Soil Chemistry
CHEM – 111: Chemistry for Engineers
CoE-1A: Group 1
Agualin, Jehmarc Karl
Agustin, Kate John Lord
Balajeboco, Dion Perry
Bañez, Jacky
Batugon, Jhonel
Cabrera, Keshley Nicole
Cacananta, Suhaila
Carpiz, Lance Jacob
Casingal, Vince Allen
Cayetano, Junuel Josh
Costales, John Lloyd
Cuchapin, Jan Lenard
Instructor: Engr. Reamlyx E. Lachica
1 Soil Chemistry
Dacuno, Charles
Daracan, Ranelle Rex
De Guzman, John Rovick
Del Cruz, Koji Ken
Estrada, Khristian Leo
Table of Contents
Table of Contents
2
Chapter 1: Introduction
3
History of Soil Chemistry
4
Origin of Soil
14
Applications
20
Chapter 2: Properties, Characteristics, Compositions,
& Different Reactions of the Soil
23
Properties of Soil
24
Characteristics of Soil
28
Compositions of Soil
31
Different Reactions of Soil
33
Chapter 3: Pollutions in the Soil
38
Definition & Health Risk
39
How Soil Pollution Affects the Environment & People
39
Types of Soil Pollution
40
Chapter 4: Human Activities that Causes the Pollution
44
Chapter 5: Governing Laws
56
Global Governing Laws
57
Local Governing Laws
66
Chapter 6: Engineering Controls
72
Responsibilities & Control of Engineers in Soil Chemistry
73
Possible Duties of an Engineer in Soil Chemistry
74
2 Soil Chemistry
Equipment Used in Soil Chemistry
75
Solid Waste Management
78
References
3 Soil Chemistry
81
Chapter 1
Introduction
Soil is a fundamental part of our ecosystem. It is the basis for plant’s source of
nutrients & contains us, living organisms. In this chapter we will tackle the history,
origin, and application ofchemistry of soil. In basic terms, soil chemistry is the study of
the chemical characteristics of soil, which are influenced by mineral composition,
organic matter, and environmental factors
This Chapter Contains:
History of Soil Chemistry
Origin of Soil
Applications of Soil Chemistry
4 Soil Chemistry
History of Soil Chemistry
Soil chemistry have been a subdiscipline of soil science ever
since it emerged. However, it has already existed for a long
period of time ever since farming started, although it was still
never considered scientific back then. Over the years, soil
chemistry has been evolving, in which this section creates the
timeline and other discoveries that contributed to further
improve soil chemistry.
Pre-History
Ever since farming started, the relationship of
humans with soil has been strong and deep, though it
was never considered to be scientific. The reason might
be because of us humans being keen observers of our
environment. This means that we attempt to find out
what impacts are beneficial to us and what is
detrimental, but not attempting on success. With soil, it
is primarily economic based where we humans used
tools available for using soil in gaining the highest yield
on labor and inputs.
Ancient Period
In Ancient Greece, soil scientists have also
emerged, with two of them being the Greek
Theophrastus (371 BC-287 BC) who wrote “On the
Causes of Plants”, and the Chinese Fan Shengzhi (1st
century BC) who wrote agricultural-related topics such
as “Filed Usage, Plowing, Irrigation, Harvesting”, and
other topics related to crops. In the modern world, they
5 Soil Chemistry
are not considered “scientists” since their works are
based on observations and never conducted experiments
to test theories. Back then, soil science is about basic
research and soil and crop productivity. What we call
“soil science” today is based on the observations and
knowledge from the scholars of Ancient Greece, Ancient
China, the Americas, and Europe.
The Renaissance
The early renaissance (specifically 16th century)
have seen scholars looking at the world in a new way.
Every aspects of the world are up to study with the
concepts of biological and chemical laws are seen to be
influenced by humans and influencing. In soil science, it
started with the exploration of soil biota and their
processes. Not long after tools that are known to be used
for soil study was invented. One such invention is the
microscope, which was invented by Zacharias and Hans
Jenssen in 1590, which lets us see microorganisms that
are invisible to the naked eye (rogitex, n.d.).
The 19th century
In the middle of the 19th century, Justus von Liebig
have theorized that fields can be fertilizes with inorganic
compounds and salts, specifically those of phosphate. His
attempts in using chemical analysis in identifying low
productivity soils and to differentiate them from highly
productive soils were not very successful. Many of
Liebig’s analytical results were hard to understand in
relationship to plant growth and soil chemistry because
it was not until the development of the concept of pH by
Sörenson and its application to soil chemistry using the
pH meter developed by Beckman that much of what was
occurring could be understood. However, these studies
did lead to the development of the law of the minimum
(Conklin, 2014, p. 6).
The study of soil chemistry was further developed
by a consultant of England’s Royal Agricultural Society in
the 1850’s, who is also deemed to be the father of soil
chemistry, J. Thomas Way. He conducted various
6 Soil Chemistry
studies regarding soil’s ability to adsorb both cations and
ions and exchange ions, discovering that soil ion
exchange was a rapid process and clay, as an important
factor cation adsorption and that heating soils or
treating them with strong acid decreased the ability of
the soils to adsorb ions. Additionally, Liebig held the
"balance-sheet" theory of plant nutrition. Soil was
considered a more or less static storage bin for plant
nutrients—the soils could be used and replaced. This
concept still has value when applied within the
framework of modern soil science, although a useful
understanding of soils goes beyond the removal of
nutrients from soil by harvested crops and their return
in manure, lime, and fertilizer.
The early geologists generally accepted the
balance-sheet theory of soil fertility and applied it within
the framework of their own discipline. They described
soil as disintegrated rock of various sorts—granite,
sandstone, glacial till, and the like. They went further,
however, and described how the weathering processes
modified this material and how geologic processes
shaped it into landforms such as glacial moraines,
alluvial plains, loess plains, and marine terraces.
The work of Liebig, Way, and Lawes provided the
basic understanding of many of the constituents in soil
including both inorganic and organic acids and bases, but
not of pH (which was not known at the time). The
importance of lime, phosphate, and sulfur was
understood, if only incompletely. Sulfur was reported as
being applied as sulfuric acid. It is, however, unclear as
to exactly how it was applied. John Laws clearly
described the changes in ammonia compounds when
they were applied to soil. Unfortunately, he was unable
to fully explain what was going on in this process
(Conklin, 2014, p. 7).
However, toward the end of the 19th century,
there were still some things about soils and chemistry
that inhibited an understanding of much of soil
chemistry. The concepts of pH and ions had not yet been
developed. Although clay was known and had been
7 Soil Chemistry
known for centuries, the varieties of clays in soil were
not known and thus their effect on soil chemistry was
unknown. The basic concepts of ion exchange and
buffering were also not yet understood either in
chemistry or in soils (Conklin, 2014, p. 8).
The first person to study soils in the United
States was a Virginian scholar named Edmund Ruffin.
He worked tirelessly to discover the secret of liming
and identified what we now know as exchangeable
calcium. In 1832, he published the first edition of An
Essay on Calcareous Manures after writing a brief
essay in the American Farmer in 1822. However, much
of what Ruffin had learned about soils had to be
rediscovered because his writings circulated only in
the South.
In 1870, the Russian school of soil science, led
by V.V. Dokuchaiev and N.M. Sibertsev, developed a
new concept of soil. They viewed soils as independent
natural bodies, each with unique properties resulting
from a unique combination of climate, living matter,
parent material, relief, and time. They hypothesized
that the properties of each soil reflected the combined
effects of the particular set of genetic factors
responsible for the soil's formation. Hans Jenny later
emphasized the functional relatedness of soil
properties and soil formation. The results of this work
became generally available to Americans through the
publication in 1914 of K.D. Glinka's textbook in
German and especially through its translation into
English by C.F. Marbut in 1927.
8 Soil Chemistry
The Russian concepts were revolutionary.
Properties of soils were no longer based wholly on
inferences from the nature of the rocks or from climate
or other environmental factors, considered singly or
collectively. Rather, by going directly to the soil itself, the
integrated expression of all these factors could be seen in
the morphology of the soils. This concept required that
all properties of soils be considered collectively in terms
of a completely integrated natural body. In short, it made
possible a science of soil.
The Golden Age of Microbiology
The period from 1890-1910 was called the Golden
Age of Microbiology. The improvements of the
microscope made scientists observe smaller and smaller
organisms. However, microscope improvements have
also divided the soil community into two camps: agro
chemists, who studied the microorganisms in labs by
extracting them from the soil, and agro-geologists, who
saw that field experiments are necessary in replicating to
consider all the factors in soils.
The agro-geologists acknowledged the soils’
heterogeneity, while agro-chemists often conclude that
“…if an organism did not grow on a gelatin or agar plate
it could not be important and thus not worth
studying.”(van Baren, Hans, et al, 75 Years the
International Society of Soil Science). In the 21st century,
9 Soil Chemistry
agriculture, this dichotomy still exists being the basis for
genetically modified crop varieties that can withstand
genetic lab breeding and intense chemical spray versus
the varieties that are open pollinated which are suitable
for regenerative agricultural practices and traditional
breeding of field plants (rogitex, n.d.).
During this time E. W. Hilgard took up the cause of
soil chemistry. He carried out research using data from
King and others in order to find a chemical
characterization of soil that would differentiate between
productive and unproductive soils. Additionally, soils
were extracted with acids of various strengths as
indicated by their specific gravity. Results of this type of
extraction were expected to indicate the long-term
productivity of a particular soil (Conklin, 2014, p. 8).
Two fundamental discoveries about the structure
of the atom and electromagnetic radiation also occurred
during this period and provided a foundation for
instrumentation that would be fundamental in
furthering our understanding of soil chemistry. One was
the discovery of X-rays, also sometimes called Röntgen
rays, discovered in 1895, by W. Röntgen. The second was
made by J. J. Thomson in 1912. He observed positive rays
and described how these could be used to identify
compounds and elements. Subsequently, he presented a
clear description of the process in 1913. This led to the
development of mass spectrometry (Conklin, 2014, p.
11).
These discoveries allowed for important increases
in the understanding of soil chemistry. The concept of
ions and the fact that some elements could exist as ions
were an essential step forward. This led to an
understanding of the phenomenon John Way clearly
described in his work of what he called base exchange, as
cited earlier. It led not only to an understanding of ion
exchange but also of soil buffering. The discovery of Xrays would eventually lead to the ability to describe and
identify soil clays that are the source of much of the
cation exchange in soils. The idea of soil pH as opposed
to soil being simply acidic or basic based on litmus paper
10 Soil Chemistry
was essential to understanding soil fertility and
contamination (Conklin, 2014, p. 11).
The 20th century
At the very beginning of the 20th century, two very
important discoveries or inventions were made. M. S.
Tswett discovered and developed chromatography and
Fritz Haber demonstrated the chemical production of
ammonia. Both of these would dramatically affect soil
chemistry. Chromatography provided a method of
separating the myriad organic and inorganic compounds
and ions found in soil. Development of the Haber process
led to the widespread use of ammonia and nitrate
fertilizers and the intense study of the chemical changes
that nitrogen undergoes in soil.
The concept of soil underwent a gradual
broadening and extension during the years following
1930, primarily through consolidation and balance. The
emphasis had been on the soil profile, but after 1930,
morphological studies were extended from single pits to
long trenches or a series of pits in an area of a soil. The
morphology of a soil came to be described by ranges of
properties deviating from a central concept instead of by
a single "typical" profile. The development of techniques
for mineralogical studies of clays also emphasized the
need for laboratory studies.
11 Soil Chemistry
The clarification and broadening of the concept of
soil science also grew out of the increasing emphasis on
detailed soil mapping. Concepts changed with increased
emphasis on predicting crop yields for each kind of soil
shown on the maps. Many of the older descriptions of
soils had not been quantitative enough, and the units of
classification had been too heterogeneous for making
yield and management predictions needed for planning
the management of individual farms or fields.
During the 1930s, soil formation was explained in
terms of loosely conceived processes, such as
"podzolization," "laterization," and "calcification." These
were presumed to be unique processes responsible for
the observed common properties of the soils of a region
(National Resources Conservation Services, 2007).
It was during this time, the 1940s, that the spin of
electrons and protons was observed by Wolfgang Pauli.
This discovery would eventually lead to the development
of NMR spectroscopy, better known simply as NMR. It is
also the basis of magnetic resonance imaging (MRI).
Also, during this time, Ernst Ruska experimented with
and developed a “lens” that could be used to focus a
beam of electrons. This led him to develop an electron
microscope with a 400× magnification. Thus, all the basic
knowledge necessary for the further development of our
understanding of soil chemistry including the
12 Soil Chemistry
instrumentation needed to explore it was in place at the
beginning of the century (Conklin, 2014, p. 13).
The middle of the century saw the development of
instrumentation based on these discoveries and the
evolution of functioning instruments that were available
from a number of manufacturers. Extracts could be
analyzed using these instruments. They were and are
constantly being improved in terms of detection,
particularly with relationship to sensitivity. Thus, they
provide the tools necessary for an even deeper
understanding of soil chemistry (Conklin, 2014, p. 14).
Turn of the Century – 20th to the 21st century
During the past few centuries, interest shifted from
simply determining if something was present in soil to
the form or “species” it was in. This was driven by the
fact that the form, often, if not always, determines its
biological availability, danger, or toxicity. This has been
described as “speciation” and is often thought of as
referring to the ionic state of the analyte in question.
However, it should also be applied to combinations of
inorganic and organic compounds and ions and their
environments.
A number of advances in instrumentation occurred
at the end of the 20th and the beginning of the 21st
centuries. Computers were being used not only to
acquire signals generated by instrumentation but also to
display the data and to manipulate it. As this process
continued, they were also used to control instruments
and to allow for automatic sample changers to be added
to instruments. Autosamplers allow samples to be
continuously analyzed even in the absence of an
instrument operator. This significantly increases the
number of samples analyzed, which greatly increases the
amount of chemical information available about a wide
variety of soils.
A type of radiation that was not available earlier
came into existence and eventually became available to
soil scientists. This is the radiation given off by
13 Soil Chemistry
synchrotrons that emit what is called synchrotron
radiation (originally considered a waste product of
acceleration electrons close to the speed of light). It is
described as similar to bright X-rays. This
electromagnetic radiation has been used to successfully
elucidate the structure and oxidation states of metals in
soil and thus their likelihood of becoming environmental
pollutants (Conklin, 2014, p.14).
Origin of Soil
The earth was formed exactly 4.6 billion years ago.
Along with formation of cosmic dust & gas particles, the
earliest form of soil are formed, in the form of large rocks
& minerals. It grew larger & larger until the earth was
formed as a rocky planet.
Soil is thought to began forming in the PreCambrian Era dating back 2,000 Million years ago (mya).
The niest soils are a result of millions of years of
weathering. By that time, no living organism is thought
to live in soil. As the nirst soils were formed in an
atmosphere with little or no oxygen & consisted of green
clays.
Soil is a lifeless matter until 400 mya during the
Devonian period, when the soil gradually began to
develop life. These soils were reddish and brownish in
colour, indicating the presence of more oxygen in the
atmosphere due to the evolution of plants capable
of photosynthesis. The nirst soil organisms also appeared
and from this period onwards living soils as we know
them truly began to form.
Soil
Soil is the thin layer of material covering the
earth’s surface. Soil was formed from rocks parent
material through weathering and natural soil erosion.
Weathering
Water, wind, pressure, temperature change,
gravity, chemical reactions, living organism, & pressure
14 Soil Chemistry
changes are all factors that contribute to rock
weathering & as a result, the formation of soil.
Soil Composition
Soil composition is a component of a soil’s nutrient
management this is very crucial in a plant’s nutrition &
growth. The soil however composed of approximately
45% mineral, 5% organic matter, 20-30% water & 2030% air.
• Mineral Matter
Mineral matter in soil consists of particles of
different sizes. Major mixtures of soils are sands
when it is 70% & above & clay not more than 15%.
Common minneral matters found in soil includes
Iron, Potassium, Magnesium, Calcium, Sulphur, etc.
• Organic Matter
Humus is the organic substaces that are
formed duento decomposition of dead &
decomposing plants & animals. Humus is an
important component of soil as it lends the soil
fertility. Additionally, organic matter innluences
soil properties & cosequently on plant grwoth,
improving the physical condition of the soil,
increasing capacity to hold water, & is commonly a
measure of plant’s health.
• Soil Water
Soil water is the water held insude the pores
of a soil. It provides the nutrients for plant’s
growth.
• Soil Air
This component of soil is the space in
between soil particles known as pore space. It can
be temporarily occupied with water or air
particles, as it is needed for plants and other
organisms underground. The decrease of soil
moisture correlates to the increase of soil air content.
15 Soil Chemistry
Soil Moisture Content
The soil moisture content of the soil can be
measured using the following methods: Gravinometric
Method Computation (GMC) & the Volumetric Method
Computation (VMC). In GMC, the soil moisture is
computated via the dividing water per volume of soil.
While VMC is computated via the weight of water over
the core unit volume. Additionally, Bulk Density can also
be computed by dividing dry weight of soil over the core
unit volume.
𝐺𝑀𝐶 =
𝑉𝑀𝐶 =
𝑤𝑎𝑡𝑒𝑟 𝑚𝑎𝑠𝑠
𝑚𝑎𝑠𝑠 𝑜𝑓 𝑑𝑟𝑦 𝑠𝑜𝑖𝑙
𝑤𝑎𝑡𝑒𝑟 𝑚𝑎𝑠𝑠
𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑑𝑟𝑦 𝑠𝑜𝑖𝑙 𝑜𝑓 𝑡ℎ𝑒 𝑐𝑜𝑟𝑒
𝐵𝑢𝑙𝑘 𝐷𝑒𝑛𝑠𝑖𝑡𝑦 =
16 Soil Chemistry
𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑑𝑟𝑦 𝑠𝑜𝑖𝑙
𝑐𝑜𝑟𝑒 𝑢𝑛𝑖𝑡 𝑣𝑜𝑙𝑢𝑚𝑒
Layers of Earth
Earth is composed of four distinct layers:
• Crust
Crust is where we live in, it is where living
organisms, soils, rocks, and most air resides.
It is the most studied layer of earth, and it is
also currently the deepest part where
mankind has been and has seen. Apart from
that we also know that crust composition
consists of 47% Oxygen, 28% Silicon, 8.9%
aluminum, 5% Iron, 4% Magnesium, 2%
Calcium, 2% Potassium, 2% Sodium, & 2%
of.other smaller amounts of gases
accumulating at the bottom.
• Mantle
Mantle on the other hand is the
thickest layer of earth. It starts at 30km
beneath the surface. It composes mostly of
iron, magnesium, silicon, & other common
silicates like olivine, ganrnet, & pyroxene.
The other major type of rock found in the
mantle is magmesium oxide.
17 Soil Chemistry
• Inner Core
Soil spheroid comprises of materials
such as metals majority of which is iron &
nickel along with siderophiles which are
elements dissolved in iron which is also
found in the outer core. The inner core
comprises of 80% Iron, 5 – 15% Nickel, 2 –
3% Siderophiles, & 5 – 10 % Sulfer &
Oxygen. It has a density at top of 12.8 g/cm3
& at bottom 13.1 g/cm3 & a 1220km radius.
• Outer Core
The outer car is made of liquid, iron
and nickel, and has an all composition of
NiFe as a reference to their elemental
symbols. It has materials of low viscosity,
which is malleable and has a great deal of
movement and convection. This year also
creates and sustain the planets magnetic
nield protecting us from solar winds and
radiation from sun and spans at 1300 miles.
The outer core has a density at top of 9.9
g/cm3 & at bottom 2.2g/cm3.
Soil ProMile
Soil pronile is the vertical
section of soil that depicts all of
horizons. It extends from soil
surface to the parent rock material.
The regolith includes all of
weathersd material within the
pronile.
• O-Horizon (Organic Layer)
The O-horizon is the
upper layer of the topsoil
which is mainly composed of organic materials,
such as the dried leaves glasses that leaves smaller
rocks, twigs surface, organisms, fallen trees, and
other decompose organic matter.
18 Soil Chemistry
• A-Horizon (Topsoil)
This horizon of soil is often black, brown or
dark brown in color, and this is mainly because of
the presence of organic content. Contains the
humus, the rich topsoil (nutrients organic matter
and biological activity takes in place) layer of soil
where plants, oats and small living beans are
active.
• B-Horizon (Subsoil)
The horizon, or the subsoil is the sub surface
that horizon, present just below the topsoil, and
above the bedrock. It is comparatively harder and
more compact than topsoil. It contains less humus,
soluble, minerals, and organic matter. It is a sight
of the deposition of certain minerals and metals
salts such as iron oxide. This layer holds more
water than the topsoil, and is lighter brown due to
the presence of clay soil, the soil of horizon-A &
horizon-B is often mixed while ploughing the
nields.
• C-Horizon (Parent Rock/Bedrock)
The C-horizon or the Saprolite is devoid of
any organic matter and is made up of broken
bedrock. The geological material present in this
zone is cemented.
• R-Horizon (Bedrock)
R-horizon is a compacted cemented layer.
Different types of rocks, such as granite, basalt and
limestone, are found here.
19 Soil Chemistry
Applications of Soil Chemistry
The use of soil chemistry can be applied to a variety of
fields. In ecology, it is used as an indicator of the ecological
condition of a wetland. It provides information about the
wetland condition, water quality, and the services that the
wetland ecosystem provides like nutrient cycling. Wetland
soils are important in absorbing phosphorus and removing
nitrogen from water but, these can also be toxic to the
organisms living in it. Additionally, high levels of nutrients,
chemicals, and/or heavy metals are unable to support the
organisms’ high diversity in the area. Soil chemistry can also
help trace elements that could cause stress and pollution
when there are high amounts of them (“Indicators: Soil
Chemistry | US EPA, 2023).
Archeology also uses soil chemistry for interpreting the
archaeological records, like how the soil was formed, altered,
and preserved. It can also draw inferences about the
behaviors of human in the past like identifying the chemical
signatures of different human activities which may leave no
physical traces, which helps assess the long-term cultivation
effects on soil productivity, reconstructing the use of earthen
material in pottery and in building different types of cultural
features like adobe houses, earth ovens, and roasting pits
(Homburg, 2005, pp. 95-102).
20 Soil Chemistry
The use of soil chemistry can help scientists learn about
the ecology of early hominins. It describes the vegetation of the
landscape whether they provide hominins with staple food,
arboreal refuge, and shade or a habitat that makes them safe
from predators. In Africa, there are plant fossils that have been
preserved which can be used as evidence for change of
vegetations. The remains are both microbotanical (microscopic
pollen grains, generally small plants) and macrobotanical
(large plants such as trees) (Sept, 2015, pp. 85-101).
The use of soil chemistry helps explain various
environmental factors such as pollution, organic and inorganic
soil contamination, and ecological and health problems. They
are used to measure speeds of chemical reaction and soil
solution ion or molecule concentrations. Soil chemistry is
important for understanding nutrient availability, soil fertility,
and the effects of pesticides in agriculture. In agricultural, it
helps determine whether the nutrients are at levels that can
support biological activity or at higher, harmful levels and also
reveal if the soil is contaminated with toxic substances or
heavy metals.
Additionally, soil chemistry can be used to modify a soil
to yield more desired qualities. This is done by replacing an old
soil into a dirt with characteristics that are able to alter the
21 Soil Chemistry
chemical composition of soils. It can either be improved by
adding organic matter, sulfur or lime, plant-nutrient-rich
fertilizer, and clay components. The pH of the soil can also be
altered. The soils’ salinity can also be lowered by either
leaching or removing the soluble salts, or adding organic
matter, uncontaminated soil material, etc. can dilute the salts
(Hawaii Cooperative Extension Service, n.d.).
In structure building, studying a soil for a structure to be
built in is vital. It is to prevent future failures so critical
understanding of the soil properties of the site is needed. One
such failure is the Leaning Tower of Pisa, which was built in
dry season that in wet season the ground sank under the
building due to stability loss. It might seem inconvenient, but a
lack of understanding with soils can lead to disastrous
construction failures (Soils, 2015).
Conclusion
The use of soil chemistry has been evolving since it was
created when it is still not considered as a scientific subject.
Prominent people such as Way, Ruffin, and Pauli among others,
have shaped the soil chemistry that we know today. Even
different fields have been applying soil chemistry, using it to
make their work efficient. Soil chemistry is one of the most
important subdiscipline of soil science, and it always will be.
22 Soil Chemistry
Chapter 2
Properties, Characteristics, Composition
& Different Reactions in the Soil
In this chapter, we will discuss the different properties, characteristics,
compositions, and reactions of the soil. By acknowledging the basic features &
properties of soil we will be able to easily understand why soil is so important in our
environment, & how it plays a crucial role for our needs in our life as a living organism.
This Chapter Contains:
Properties of Soil
Characteristics of Soil
Composition of Soil
Different Reactions in the Soil
23 Soil Chemistry
Properties of Soil
The soil has four physical aspects that are essential
in studying soil. They are texture, structure, water-holding
capacity, and pH. Below are the explanations and how it
can influence their environment.
• Texture
It defines what the soil feels like when
touched. The soil’s texture can be smooth, that can
24 Soil Chemistry
indicate a clayey soil, or rough and course,
indicating a sandy soil. The composition of a soil in
terms of sand, silt, clay, and organic matter
influences its behavior, management potential, and
allowable use. Clay soils are harder to cultivate, hold
a lot of water, and can be waterlogged, especially in
winter, while sandy soils are easier to cultivate but
tend to hold less water and can be dry.
• Structure
In terms of structure, it is about the
arrangement of soil particles called aggregates or
‘peds’, into a larger cluster. Aggregation has
importance in increasing stability against erosion, in
maintaining porosity and soil movement, and in
improvement of fertility and carbon sequestration
in the soil (Nichols et al., 2004). Aggregation is
mostly described in terms of grade (degree of
aggregation), class (average size), and types (form).
Some soils may have different kinds of aggregates
found together, describing them separately.
Additionally, soil technicians recognize seven types
of soil structure namely:
o Granular – rounded surface
o Crumb – rounded surface, larger than
granular
o Subangular blocky – cube-like with flattened
surfaces and rounded corners
o Blocky – cube-like with flattened surfaces and
sharp corners
o Prismatic – rectangular with long vertical
dimension and flattened top
o Columnar – rectangular with a long vertical
dimension and rounded top
o Platy – rectangular with a long horizontal dimension
25 Soil Chemistry
• Water-holding Capacity
Describes how soils can retain water in their
pores as well as on the surfaces of structural
aggregates and mineral grains. The capacity
depends on soil to soil, with the texture being
correlated. As mentioned in texture, sandy soils
have low water-holding capacity and are unable to
retain large amounts of them, having their common
name being ‘thirsty soils’. In contrast, clay soils
have pores that allow them to store water, being
the reason why plants grow on them.
• pH Scale
The pH scale describes the soil’s acidity (0-7)
and acidity (7-14). Most soils in the world have a
range between 5.5 and 7.5, although the pH range
of them is typically between 3 and 8. Which means
that soil is classified as acidic and alkaline. The
ecology of an area is based on the soil’s pH.
These aspects help us understand soils more.
We can study their smoothness and roughness,
which can influence how much they can retain
water. The structure of a soil, figuring out how
aggregation can be beneficial against erosions and
26 Soil Chemistry
in improvement of soil’s fertility. We can study how
the pH scale can be a basis on the ecology that can
live in a certain area.
• Desirable Soil pH for Plants
Different plants have its different needs. As
such, some plants require a specific range of soil pH
in order to yield significantly. Most plants best grow
in the 6.0 to 7.0 range, while other plants prefer a
slightly more acidic condition of soil.
In nature, due to the different weathers &
climates, plant growth differs significantly region by
region. Areas with low rainfall conditions tend to be
baisc with soil range around 7.0. While soils under
conditions of high annual rainfall tends to be more
acidic.
Soil pH can be manipulated throgh nitrogen
fertilzers or manures. As such farmers before & now
prefer to use fertilizers in order to have a larger
crop yield. Through intensife farming this can make
soil more acidic, giving the chance of fewer crop
yield.
• pH Range for Some Plants
5.0 – 5.5 (Some Vegetables, Fruits, Trees, &
Flowering Plants) e.g:
Apple, Blueberries, Birch, Hydrangea
(Blue flower), Laurel, Pine, Potato
5.5 – 6.5 (For Vegetable, Grasses, &
Ornamentals) e.g:
Barley, White Oak, Red Raspberry,
Tomato, Chestnut, Cotton, Wheat
6.5 – 7.0 (Most Plants) e.g:
Sour Cherry, Spinach, Hydrangea (Pink
flower), Lemon, Maple, Sweet Pea
27 Soil Chemistry
Characteristics of Soil
Some characteristics of a soil have been previously
mentioned in the ‘properties’ section. This section will be
about the other characteristics of the soil.
• Color
The color of the soil can be influenced by the
soil’s mineral, water, and organic composition. For
example, a soil high in iron have a deep orangebrown to yellowish-brown color, while those that
have high organic matter are dark brown or black.
The color can also be affected by the temperature and
moisture content of the soil’s surrounding area.
• Depth
It is vital to study a soil’s depth for plant
growth. The root penetration can be restricted by any
discontinuities depending on the soil profile, from
sand or gravel layers to bedrock. The type of plants
that can grow in a given soil could be influenced from
the depth of the soil. Meaning, deeper soils can supply
plants with more nutrients and water than shallower
soils. The depth can also limit drainage during
periods of high-water content, which may impact soil
oxygenation.
• Porosity
Describes the portion of a soil volume occupied
by pore space. With pore space, air and water can be
available and has ease in movement about the soil
environment. They have an impact on soil
biodiversity because of the room they create for
microbes. Factors such as movements of worm,
insects and roots, dissolution of the soil’s parent
materials, and/or expansion of grass trapped by
groundwater in these spaces can create pores.
Texture can also influence porosity.
We can calculate the soil porosity using the
formula:
28 Soil Chemistry
!"
Where:
𝑆𝑜𝑖𝑙 𝑃𝑡 = !#
Soil Pt = Soil Porosity in %
ρB = Bulk Density in cm3
ρP = Particle Density in cm3
• Permeability
It is the ability of soil in allowing water to flow
through. The flow of water takes place in
interconnected void spaces and is connected to
structures that have water contact. The water flows in
a winding path, although the flow is considered
straight at an effective velocity in soil mechanics. The
flow velocity depends on the pore size.
• Salinity
Soils affected by salt are saline and sodic, which
occurs in every continent and under almost climactic
conditions. Salinity in soil can naturally occur overtime
due to environmental weathering. However, their
distribution is more extensive in arid and semi-arid
regions compared to humid regions. Salinization and
sodification are major degradation processes for soils
which threatens the ecosystem and recognized as one
of the most important problems globally for
agricultural production, food security, and
sustainability in arid and semi-arid regions. In every
continent, there are areas whose soils are salt affected,
but their extent and distribution have not been studied
in detail.
Plants can tolerate a certain amount of salinity.
The salt tolerance of some plants changes with growth
stages. Soil salinity is measured in terms of the soil’s
level of Electrical Conductivity (EC) in reference to the
soil’s SAR or the “ratio of sodium” in soil.
As such, “Non-Saline” (most plants) grow at the
soil salinity condition of EC is less than 2 SAR.
Meanwhile, some crops are considered Saline when
29 Soil Chemistry
their soil salinity condition is around 2 and less than
13 EC. A crop can also be considered “Sodic” when
its soil condition is less than 4 & less than 13. & a
crop is considered “Saline-Sodic” when its EC is
greater than or greater than 13.
• Fertility
Refers to the soil’s ability to sustain plant
growth by providing nutrients and the favorable
chemical, physical, and biological characteristics of
the soil as a habitat for the plant. Nutrients for
plants include macronutrients, like nitrogen and
sulfur, and micronutrients like copper, boron, and
iron. Fertilizers, whether, chemical, natural, or
organic, also helps in providing nutrients for plants,
usually by applying it into the soil. Some soil traits
are also needed to be considered for a plant to grow
like its acidity and alkalinity.
These characteristics enable scientists to
assess how the ecosystem works and give
recommendations for soil usage that have the least
possible impact on the ecosystem. Soil
characterization data, for example, can help evaluate
if a garden or a school should be developed.
Scientists can use soil characterization data to
estimate the possibility of flooding and drought. It
can assist them in determining the optimal sorts of
plants and land usage for a given site. Patterns
noticed from soil characteristics can also be
explained. Satellite imaging, vegetation growth over
the terrain, or weather-related patterns in soil
moisture and temperature (Globe Program, 2016).
30 Soil Chemistry
Compositions of Soil
Soil is composed of four main materials: minerals,
water, air, and organic matter.
Mineral makes up the most volume of soil with 45%.
They are solid and occur naturally with a fixed chemical
composition. The main minerals that are present in soil
are olivine and feldspar. The most common minerals for
plant development, however, are phosphorus, potassium,
and nitrogen gas, which can be categorized in air.
Minerals are also divided into three size classes
namely clay, silt, and sand. An example is smectite, which
is a clay mineral, which may shrink when wet and swell
rapidly when dry, which can knock over structures.
Soil also consists of water which makes up about
25% (¼) of its volume. The soil dissolves their minerals
and nutrients that is then transferred to plants and their
parts. Water is an essential factor for a plant to grow and
develop.
Soil Compositions
Organic
Matter, 5%
Air, 25%
Minerals,
45%
Water, 25%
Minerals
Water
Air
Organic Matter
Air holds about 25% (¼) of the volume of soil and
the pores on the soil are filled with them. In the pores, the
nitrogen and oxygen are mostly the air which came from
the atmosphere, only fixed by microorganisms. The
31 Soil Chemistry
microorganisms mentioned produce gas which makes the
composition of carbon dioxide higher.
Lastly, organic matters are also present in soil and
consists 5% of the soil’s volume. They are found in small
amounts and are mostly from dead animals and plants.
There are three types of organic matters, which are the
three stages of decomposition: completely decomposed,
partially decomposed, and undecomposed.
These components not only define what the soil
consists of, they are also factors that can help the growth
and development of a plant. Additionally, the soil
components can be categorized into two: biotic and
abiotic. These factors make up the composition of the soil.
Biotic means living and once-living things. In soil,
the biotic factors are mainly organic matters, such as
plants and animals.
Abiotic is the opposite, which are non-living things.
These category consists of the remaining three materials
which are water, air, and minerals.
As written by Gross and Oliver (2023), soil
composition and organization have the ability to record so
much information regarding its land use overtime. To
study soils that have been influenced by human activities,
32 Soil Chemistry
we need to use a variety of approaches that span multiple
disciplines and scales. Human activities can change all the
factors that contribute to soil formation, which can affect
how these soils evolve over time. If the main processes
that shape human-affected soils are similar to those that
shape natural soils, then the conditions that humans
create can change the way these soils develop. To manage
soils in inhabited areas in a sustainable way, we need to
improve our understanding of soil quality and how it
changes over time.
Different Reactions in the Soil
There are three types of reaction in soil chemistry:
Alkaline, Acidic, and Neutral.
• Alkaline Reaction
commonly takes place in soils with high
degree base of saturation. Salts affect the
alkalinity of soil as salts with high bases such as
sodium carbonate, tend to homogenize with the
soil. Other salts such as carbonates of calcium,
magnesium and sodium soil solutions could give
vast numbers of OH ions than H ions in the soil
solution. These soils commonly occur in arid or
semi-arid regions. The chemical reaction
includes:
2𝑁𝑎$ +𝐶𝑂%&' + 2𝐻' 𝑂 → 2𝑁𝑎$ + 2𝑂𝐻& + 𝐻' 𝐶𝑂%
• Acidic Reaction
Can takes place when the soil solution
undergoes chemical reaction in areas where rain
occurs most often, providing numerous
exchangeable bases on the soil solution’s surface
layer. This results to the domination of H ions in
the soil solution and has an impact to plant’s
growth in regions with acidic soil.
This can reaction can also occur during liming.
Example of acidic reaction when liming:
33 Soil Chemistry
CaSO4 + 2H2O → Ca (OH)2 + H2SO4
• Neutral Reaction
contains a balance of H and OH ions in the soil
solution’s composition and the ionization of
compounds as stated in the theory of
dissociation.
There are also factors considered that affects soil
reaction:
•
Nature of Soil Colloid
Soil colloid determines the soil
reaction as soil tends to be acidic if
adsorbed H+ ions dominated soil
colloids otherwise, becoming alkaline if
hydroxyl ions came in contact with soil
colloid.
• Nature of Ion
The soil that contains more hydrogen ion than
hydroxyl ions become acidic in reaction. When the
aluminium ions are present in the soil, they react
with water to liberate hydrogen ions, which
increases the soil acidity.
𝐴𝑙 %$ + 3𝐻𝑂𝐻 → 𝐴𝑙 (𝑂𝐻)% + 3𝐻$
• Percentage Base Saturation
34 Soil Chemistry
A low percentage base saturation of soil
means soil acidity. In humid areas, the basic
elements have been leached down from the soil, the
percentage base saturation decreases much below
80 and they become acidic in reaction. If the
percentage of base saturation is above 80 and at 90,
then they become neutral in reaction and alkaline
reaction respectively.
• Rainfall
Rainfall plays important role in determining
the soil reaction. The soils that are developed in high
rainfall areas, becomes acidic in nature due to
leaching of some nutrients such as calcium (Ca++),
magnesium (Mg++) etc. from soil solution. So,
leaching encourages the development of soil acidity.
On other hand, the soils that are developed in low
rainfall areas, becomes alkaline in nature.
• Fertilizers
The continual use of fertilizers is responsible
for a marked change in soil pH. Acid forming
fertilizers such as Ammonium sulphate, Urea,
Ammonium nitrate etc. when applied in the soil in
large quantities makes the soil acidic. On the other
hand, basic fertilizers such Sodium nitrate, Basic
slag etc. makes the soil alkaline.
35 Soil Chemistry
• Subsoil Acidity
Subsoil acidity refers to the pH level of soil
below the topsoil layer. Soil acidity is commonly
measured on a pH scale ranging from 0 to 14, with 7
being the most neutral. This measure indicates the
alkilinity or the acidity of a soil, wherein soil at pH
level below 7 indicates acidic soil, while a soil at pH
level above 7 idicates that the soil is alkaline. When
subsoils pH level drops below 5.0, aluminum &
manganese in the soil become more soluble, & in
some soils may be toxic for some plants. Under
these conditions, some crops may produce less
yield.
• Soil Liming
Liming is a process used by farmers in order
to increase or overcome the constraints of soil
acidity (by increasing the pH level) for enhanced
crop yield. This process involves the application of
calcium & magnesium rich materials to the soil in
the form of marl, chalk, limestone, or burnt lime.
The reactions of soil chemistry are always based on
the pH scale. Moreover, the manipulation of humans in a
soil’s pH level can contribute to the effect the soil brings
around its environments.
36 Soil Chemistry
Conclusion
Soil chemistry can be used as a basis for a lot of
things. First, it can be determined if a plant can live and
sustain its life on a certain area with a certain soil. The
types of organisms that can live there are also to be
considered. We can find the differences between soils and
how it can affect their environment, and how the
environment affects them. Finally, how it reacts on certain
factors can be used as a way on how we, as humans, use
these factors to manipulate soil’s pH level for the crops to
grow.
37 Soil Chemistry
Chapter 3
Pollution Involved in the Soil
Soil Pollution is a major threat to our ecosystem and our surivival, as it affects
soil fertility; this jeopardieses food security, which is essential for human survival. In
this chapter we will discuss the different types of pollutions affecting the soil.
This Chapter Contains:
Definition & Health Risks
How Soil Pollution Affects the Environment & People
Types of Soil Pollution
38 Soil Chemistry
Definition and Health Risk
The term "soil pollution" refers to the various
contaminants that are induced into the soil that have a
negative effect on ecosystems, the environment, and human
health. Its numerous health risks make it a major
environmental problem. Exposure to soil that has elevated
levels of such contaminants may result in various long-term
diseases such as cancer, nervous system damage,
neuromuscular blockage, depression of the central nervous
system, kidney damage, and liver damage.
How Soil Pollution Affects the
Environment and People
Chemicals and pathogens are among the soil
contaminants that can take on interchangeable liquid, solid,
or gaseous forms and mix until a satisfactory equilibrium is
achieved between them. The liquid forms fill the spaces
created by the pores between soil particles; the gaseous
forms envelop the air between soil particles; and the solid
forms are absorbed or combined with soil particles. This
implies that we may be exposed to soil contamination in the
gaseous, liquid, or solid forms either concurrently or
separately. Indirectly, soil pollution can enter our systems
39 Soil Chemistry
through the eating of food, particularly vegetables grown in
polluted soil, or by inhaling the harmful vapors of volatile
chemicals polluting the soil. Directly, it can enter through skin
contact, inhalation of soil dust or soil particles, or both.
Types of Soil Pollution
The main causes of soil degradation that exist today are
phenomena like erosion, loss of organic carbon, increasing salt
content, compacting, acidification, and chemical
contamination. Furthermore, the FAO (Food and Agriculture
Organization) makes a distinction between two categories of
soil pollution:
Specific pollution: accounted for by particular causes, occurs in
small areas, and the cause can be easily identified. Such soil
pollution is often found in cities, old factory sites, around
roads, illegal landfills, and wastewater treatment plants.
Widespread pollution: covers a large area and has multiple
sources that can be difficult to pinpoint. Examples of these
include the serious harm that air-ground-water systems due to
human health and the ecosystem by dispersing contaminants.
Examples of pollution that pollutes the soil include:
• Plastic Pollution: Improper disposal of plastic materials
can lead to the accumulation of microplastics in the soil.
This can affect soil structure and nutrient cycling.
40 Soil Chemistry
• Nitrate Pollution: Nitrogen occurs in many forms in the
environment and takes part in many biochemical
reactions. The four forms of nitrogen that are of
particular significance in environmental technology are
organic nitrogen, ammonia nitrogen, nitrite nitrogen,
and nitrate nitrogen. Nitrates can enter the groundwater
from chemical fertilizers used in agricultural areas.
Excessive nitrate concentrations in drinking water pose
an immediate and serious health threat to infants under
3 months of age.
• Urban Wastes: Urban wastes consist of both
commercial and domestic wastes consisting of dried
sludge and sewage. All the urban solid wastes are
commonly referred to as refuse. Constituents of urban
refuse: This refuse consists of garbage and rubbish
materials like plastics, glasses, metallic cans, fibers,
paper, rubbers, street sweepings, fuel residues, leaves,
containers, abandoned vehicles, and other discarded
manufactured products. Urban domestic waste, though
disposed of separately from industrial waste, can still be
dangerous. This happens because they are not easily
degraded.
• Industrial and Mining Activities: Since the amount of
mining and manufacturing has increased, most
41 Soil Chemistry
industries are dependent on extracting minerals from the earth.
Whether it is iron ore or coal, the by-products are contaminated, and
they are not disposed of in a manner that can be considered safe. As a
result, the industrial waste dumped on the soil surface
for a long period of time degrades it.
• Radioactive Pollution: Pollution that comes from
radioactive substances that came from explosions of
nuclear testing laboratories, radioactive fallout, and
nuclear dust and nuclear waste that industries gave rise
to. All of these may penetrate the soil, and their
accumulation can result in soil pollution.
• Soil Acidification: Mainly caused by acid rains, which
are rains mixed with sulfur dioxide and nitrogen oxide
emissions that come from transportation and industrial
sources. Due to the acidification, the pH of soil is altered,
and the availability of nutrients for plants is affected.
• Oil Spills: Result from the improper disposal of
petroleum-based products, such as petroleum
hydrocarbons. Accidental spills can also be the cause of
an oil spill. Near oil refineries and gas stations are some
of the areas that mostly have these occurrences.
• Soil Contamination via Chemicals: The use of various
chemicals in the soil can have long-lasting effects. For
example, when chlorinated solvents, which are mainly
used in industrial processes, are used and disposed of,
their effects can persist in the environment for a long
42 Soil Chemistry
period of time. Some chemicals not only harm the soil
but also other environments, like water. Examples
include the use of pesticides and fertilizers, which can be
toxic to other organisms such as birds, fish, beneficial
insects, and harmless plants. Additionally, the excessive
use of these two can also contribute to soil pollution.
• Urbanization: Terraforming land into a place into a city
is another form of soil pollution. It not only destroys the
biodiversity of the place; other effects, like the increase
in temperature, can also be an impact of urbanization.
Related to urbanization, lands are also terraformed in
order to increase farming space. It leads to a decrease in
soil organic matter and also loses the biodiversity it
previously had, which can contribute to the
contaminants’ mobilization.
• Heavy Metal Pollution: Heavy metals are the hardest to
remediate due to their persistence and complexity as
pollutants. The quality of the atmosphere, water bodies,
and food crops is degraded due to them. Moreover, the
health of both animals and humans is being threatened
because of heavy metals. Thankfully, a promising
strategy has emerged that can combat the heavy
concentration of heavy metals in the environment. The
microbial bio-remediation demonstrated that the ability
of the microorganisms, especially bacteria, to sequester
and transform heavy metal compounds
43 Soil Chemistry
Chapter 4
Human Activities that Cause the
Pollution
Humans has been the major cause of pollution & pollution to soil is no exception.
As humanity progress and develop new technologies, the growing demand for resources
grow significantly as much. As mentioned in the previous chapters, soil has been an
important part of our life, it is the source of our basic need of food & the main reason
how we are living. Despite that, humans have also been the major cause of its
deterioration. In this chapter, the human activities that drives the pollution to soil are
further discussed.
44 Soil Chemistry
Human Activities that Cause the
Pollution
This chapter is based upon the prior chapter wherein 10
different types of pollutions affecting the soil are identified. In
this chapter these different types of pollutions are further
elaborated as it is explained what human activities causes such
pollution.
Plastic Pollution
Plastic waste is unavoidably put into the environment.
Exposure to the environment deteriorates the mechanical and
physicochemical qualities of the waste and causes plastic
fragments to form. These fragments are referred to as
microplastics when their size is less than 5 mm. These tiny
plastic particles have the power to alter the earth's composition
beneath our feet and reduce its ability to retain water.
Microplastics can potentially have an impact on plants by
inhibiting root development and nutrient uptake. The direct
release of primary microplastics into the environment can
occur through a variety of means, such as product use (e.g.,
washing personal care products into wastewater systems from
homes), inadvertent spills during production or transportation,
or abrasion during washing (e.g., laundering of clothing made
45 Soil Chemistry
with synthetic textiles). It is anticipated that the existing
effects and severity of soil microplastic pollution on soil health
attributes will remain for a very long time, particularly given
the rising worldwide plastic production (Zhang et. al., 2021).
Addressing this multifaceted issue requires a
comprehensive strategy, encompassing heightened awareness,
responsible consumer behavior, and the development of
sustainable alternatives to alleviate the adverse impacts of
plastic on our environment (Plastic Soup Foundation, 2011)
Plastic, a remarkably enduring creation of humanity, is
now widely recognized for its slow degradation, potentially
taking centuries and transforming into microplastics. These
minuscule plastic particles pose a severe threat as they can be
ingested by marine animals, entering their bodies and tissues,
ultimately disrupting the food chain and having dire
consequences for our planet's health and its inhabitants.While
awareness of the hazards posed by plastic is growing among
humans, the presence of this material in our oceans continues
to surge. Plastic pollution remains a primary driver of marine
species extinction, causing health issues for both humans and
animals, and contributing to the widespread destruction of our
ecosystems. Despite increased awareness, the escalating
impact of plastic pollution demands urgent and concerted
efforts to mitigate its far-reaching consequences (UNESCO,
2022).
46 Soil Chemistry
Nitrate Pollution
Nitrate pollution doesn’t only come from water,
groundwater is also affected by this problem. Nitrate pollution
usually comes from human activities. Such causes like animal
or human waste, sewage systems, concentrated animal
farming, fertilizer applications, and many others are the
reasons why such pollution exists. This type of pollution is one
of the most concerned health risk in the world, where the issue
is increasing over time. If the contaminated water, which if it
exceeds the World Health Organization’s guideline limit of 50
mg of NO3/L, by a person, high chances of methemoglobinemia
can affect the drinker with the severity depending on the
amount of contaminated water drank. This is a problem which
can threaten the lives of humans and to the environment
(Wakejo, et. al., 2022).
Urban Waste
Increase in urbanization has resulted in enormous
amount of waste generation. More than half percent of all
world population lives in urban areas. The rate of urbanization
is expected to increase by 1.5 times by 2045. The waste
generation from urban areas is increasing at a pace double
than the rate of urbanization itself. The waste generation will
increase approximately 2 times by 2045.
Urbanization is defined as moderation of an urban area
based on economic and social status towards a more urban
area having service sectors and industries. In recent years, the
47 Soil Chemistry
developing countries having an economic transition
via urbanization and have high demand of energy resources.
The world population keeps on increasing but at a slower pace
as compared to 1950 probably due to the reduced fertility
level. From an estimated world population of 7.7 billion in
2019, world population is estimated to rise to 8.5 billion in
2013 to 9.7 billion in 2050 and 10.9 billion in 2100. About 55%
of world total population lives in urban areas. The urban
population will increase 1.5 times reaching six billion by 2045.
There are many kinds of wastes generated in urban
areas of the world. Most common among these waste types are
residential waste, industrial waste, hospital waste, MSW, agricultural waste, biomedical wastes, and e-waste.
Wastes are the byproducts of biota. It is the rule of
nature that every living person on earth generate wastes, and
when individuals die, they are also considered as wastes. The
residential wastes are mostly solid in nature. It is estimated
that 3.5 billion or 52% of all over the world population does
not have access to solid waste management
in residential areas.
The production of residential wastes depends upon the
economy and size of the residential area. Higher the income
value and larger the residential area, the more will be
production of household wastes. The problems for the
management of household wastes will keep on increasing with
increasing urbanization and financial status of any area. The
amount of household wastes worldwide is approximately
991,901,800 tons (Noor, T., Javid, et. al., 2020).
48 Soil Chemistry
Industrial & Mining Pollution
Mining activities can contaminate soil through improper
disposal of mining waste. As a result of these wastes contact
with the atmospheric agents, toxic elements such as arsenic,
cadmium, chromium, copper, mercury, nickel, lead, tin,
titanium, and zinc leach out and contaminate the soil, which
serves as a filter. For industrial activities, additional cause of
pollution is incidents that are connected to industrial activities.
Examples of these are abandoned industrial sites, historical
long-term industrial pollution, and waste disposal sites that
were not managed in an environmentally sound manner. These
all continue to pollute soil. Historically, mining and
manufacturing have been the main industrial processes that
pollute the soil. The concentrations of organic pollutants and
trace elements are generally substantially greater in industrial
locations. This is because industrial operations discharge
pollutants into the environment such as the soil, nearby water
bodies, and the atmosphere intentionally and unintentionally
(FAO and UNEP, 2021).
49 Soil Chemistry
Radioactive Pollution
Radioactive pollution can cause serious problems in
terms of soil fertility. Improper radioactive waste disposal
can cause severe contamination to the soil & result in almost
irreversible soil pollution. This kind of pollution occurs
naturally at the possibility rate of near zero. The driving
cause of radioactive pollution are mainly human activities,
such as improper disposal of radioactive material, rendering
the soil toxic & infertile. This type of pollution is caused
mainly by some irresponsible nuclear power plants,
accidentally releasing radioactive materials around. Nuclear
weapon testing, & inadequate practices of radioactive waste
disposal are also some of the principal human activities
responsible for radioactive contamination (Smičklas &
Šljivić-Ivanović, 2016).
Soil Acidification
Because soil is so important to human life, humans
must move and manipulate it in order to use it. This,
however, has the potential to cause environmental issues,
soil loss, and degradation. Soil degradation is a man-made or
natural process that reduces soil's ability to function.
Acidification occurs when basic cations (such as calcium and
magnesium) leach from the soil, leaving the acidic cations
(hydrogen, aluminum, iron, and manganese) in the soil. The
pH drops, and the soil becomes more acidic. This is a natural
50 Soil Chemistry
weathering process. However, the application of some
fertilizers, such as anhydrous ammonia, to produce food leads
soil to become considerably more acidic much faster. This can
happen in any biome (Soils for Teachers, n.d)
Soil acidification is a natural process that can be
hastened or slowed by particular plants and human activities.
Soil acidification is induced by acid produced by pyrite
oxidation and acid precipitation caused by sulfur (S) and
nitrogen (N) gas emissions from industrial and mining
activities. Soil acidification in controlled ecosystems is
primarily induced by the release of protons (H+) during the
transformation and cycling of carbon (C), N, and S, as well as
fertilizer reactions. Soil acidification generated by these
processes can have negative consequences if soils are unable
to buffer future pH decreases (Bolan et al., 2005)
Oil Spills
Human activity cause oil spill from various form of
human error, negligence, or intentional actions. And some of
those activities are accidental spills during oil extraction and
transportation, oil platform accidents, illegal dumping, and
intentional spills. Accidental spills during oil extraction
and transportation happen if there’s an accident during
drilling, blowouts, pipeline rupture, or tanker accident that can
51 Soil Chemistry
lead to large scale oil spills. This happen because the process of
extracting oil from ground and transporting involves complex
machinery and infrastructure. Oil platform accidents, accidents
on these platforms, such as equipment failures, fires, or
blowouts, can lead to oil spills. The contributing factor tothis
accident is human error in maintenance, monitoring, or
emergency response. And as for illegal dumping and
intentional spills, this happens to avoid the cost of proper
disposal, so some individuals or companies intentionally dump
oil in land, sea, or in rivers, this happens because of lack of
environmental awareness, cost cutting motives, or disregard
for regulations. So, to prevent oil spills, implement and enforce
regulation, use advanced technologies for monitoring and
response, and promoting environmental awareness and
responsibility within the industry.
Accidents involving tankers, barges, pipelines, refineries,
drilling rigs, and storage facilities responsibility by people are
the most common causes of oil spills into rivers, bays, and the
ocean. Spills can occur as a result of people making mistakes or
being irresponsible. Equipment failure and also terrorist
attacks, acts of war, vandals, or illegal dumping can cause oil
spill (Office of Response & Restoration, 2019).
Urbanization
Land pollution is unavoidably caused by a large number
of people living close to one another, creating trash, and
littering in a crowded area. Construction projects are also
carried out to accommodate our growing population, and these
projects generate a lot of waste materials, including bricks,
metal, plastic, and wood. These materials contribute to the
land pollution in that area when they are not disposed of
properly (Texas Disposal Systems, 2023).
The growth of urban areas and their activities has a
significant impact on the environment, especially on the soil
that supports life. However, people living in cities have lost
their connection with the soil and its benefits. A literature
review reveals that urban activities can affect the soil
conditions and pollution levels not only in the city, but also in
52 Soil Chemistry
distant places. The soil in urban areas has changed in its physical and
biochemical properties and pollutant loads, which reduces its ability to
provide life-supporting services. Many cities in developing countries have
high levels of soil pollution due to industrialization, which requires urgent
action. We propose a global assessment of urban soils to understand how
human activities have affected them in different ways. We also recommend
soil protection and remediation in areas that are already affected by urban
development (“Chapter 3. Sources of Soil Pollution…”. n.d.).
More than half of the world’s people live in urban areas, where soils
are exposed to many human activities that can pollute them. Urban soils
are very important to assess and monitor, because they provide many
benefits for the environment and people, such as storing nutrients and
organic carbon, producing food, and offering cultural and recreational
opportunities. However, soil pollution in urban green areas can pose a risk
to the health of living beings, so it needs special attention (Peter, Braimoh,
& Onishi, 2008).
Due to the growing percentage of the world's population living in
urban areas and the high level of activity that urban dwellers engage in,
cities are significant drivers of environmental trends. But as the world gets
53 Soil Chemistry
more urbanized, people are becoming less and less aware of
the importance of soil and the resources it needs to support
life. The physical, chemical, and pollutant loads of soil, as well
as the effects of urban processes and cities on these factors,
have all had a significant and varied impact on the lifesupporting functions of soils. The level of soil pollution in
developing nations' cities is rising to the point where urgent
action is needed as these nations continue to industrialize
(Marcotullio, P. J., Braimoh, A. K., & Onishi, T., 2008).
Heavy Metal Pollution
According to Zhao et.al (2022), the accumulation of
heavy metals such as arsenic (As), cadmium (Cd), chromium
(Cr), mercury (Hg), lead (Pb), copper (Cu), zinc (Zn), nickel
(Ni) is considered toxic in the soil composition. These heavy
metals are commonly found in large industrial regions most
likely in China due to excess manufacturing, incorrect disposal
of wastes and industrialization. Moreover, China’s agricultural
regions has faced a decline in soil nourishment and has been
contaminated by said heavy metals with a recorded pollution
percentage of 16.1%. in which Cd, As, Hg, Pb, Cr heavy metals
had over standard rates of heavy metals are as high as 7.00%,
2.70%, 1.60%, 1.50%, 1.10%, respectively. In the past 50 years
Lead (Pb)has a record of 800,000 tons so as Chromium (Cr)
54 Soil Chemistry
reaching approximately 30,000 tons of heavy metals released
worldwide while in 2009, Cadmium (Cd) has a total of 743.77
tons of global emissions in heavy metals.
Different human activities such as rapid rate of
industrialization, destruction of environment and
anthropogenic rise in human population rate raised an
alarming concern of heavy metal disposal in soil, causing
pollution and has been a significant threat to every living
being’s existence. In addition to that, activities such as mining,
industrial production, and the use of metal-containing
compounds in domestic and agricultural settings contribute to
soil pollution. Heavy metal-infested soil poses risks and
hazards to the society and environment. It greatly affects a
state’s agricultural production, food chain safety, security &
quality and lastly, exacerbates land tenure problems.
55 Soil Chemistry
Chapter 5
Governing Laws
Humans are the driving cause for soil pollution, as such we as humans have the
responsibility to maintain & prevent the destruction of our own land. In this chapter we
will discuss the different governing laws present in both local & international fields.
This Chapter Contains:
Global Governing Laws
Local Governing Laws
56 Soil Chemistry
Global Governing Laws
Turkey
Soil Preservation and Land Utilization
(Law No. 5403)
There are many laws that protect the soil on
our planet. These laws are here to protect and
preserve soil so that we can have healthy soil to use
and to plant trees to prevent disasters and reduce
global warming. One example of a global law that
protects soil is Law No. 5403 on Soil Prevention and
Land Utilization. This law outlines rules for
classifying land and its resources and develops plans
for them. Land can be categorized as marginal
farming land, cultivated land, special crop land, or
farming land. Farming lands cannot be used for
other purposes except for defined plans. Land use
plans cover agricultural, pastureland, forest, special
laws, settlements, and infrastructure facilities.
Sri Lanka
Soil Conservation Act 1951
(No. 25 of 1951)
57 Soil Chemistry
AN ACT TO MAKE PROVISION FOR THE
CONSERVATION OF SOIL RESOURCES, FOR THE
PREVENTION OR MITIGATION OF SOIL EROSION,
AND FOR THE PROTECTION OF LAND AGAINST
DAMAGE BY FLOODS AND DROUGHT.
The objectives of this act are to preserve soil,
prevent soil erosion, conserve soil, and protect land
from drought and flood. The director of agriculture
will carry out investigations and surveys for
damages caused by drought or flood, and the
minister can declare erodible areas based on them.
Also, under this act, the Minister can also make
regulations that are applicable to erodible areas.
Regulations include requiring landowners to
prevent soil erosion, prohibiting clean weeding,
restricting land use for agricultural purposes,
controlling forest and grass resource exploitation,
and directing crop cultivation. Protective measures
also include the minister's power to acquire land.
Stockholm Convention on Persistent Organic
Pollutants
Stockholm Convetion on Persistent Organic
Pollutants is a global treaty that aims to protect
human health and the environment from chemicals
that remain intact in the environment for long
periods, become widely distributed geographically,
accumulate in the fatty tissue of humans and
wildlife, and have adverse effects on human health
or the environment. The treaty was signed in 2001
and became effective in May 2004.
The convention has a list of 30 chemicals that
are banned or restricted, including pesticides such
as DDT, industrial chemicals such as polychlorinated
biphenyls (PCBs), and unintentional by-products of
industrial processes such as dioxins and
furans 1. The treaty also provides a framework for
the addition of new chemicals to the list 1.
58 Soil Chemistry
The example of compounds band in Stockholm
Convention List are:
1. Aldrin
an insecticide used in soils to
kill termites, grasshoppers, Western corn
rootworm, and others, is also known to kill birds,
fish, and humans. Humans are primarily exposed to
aldrin through dairy products and animal meats.
2. Chlordane
an insecticide used to control termites and
on a range of agricultural crops, is known to be
lethal in various species of birds, including mallard
ducks, bobwhite quail, and pink shrimp; it is a
chemical that remains in the soil with a
reported half-life of one year. Chlordane has been
postulated to affect the human immune system and
is classified as a possible human carcinogen.
Chlordane air pollution is believed the primary
route of humane exposure.
3. Dieldrin
a pesticide used to control termites, textile
pests, insect-borne diseases and insects living in
agricultural soils. In soil and insects, aldrin can be
oxidized, resulting in rapid conversion to dieldrin.
Dieldrin’s half-life is approximately five
years. Dieldrin is highly toxic to fish and other
aquatic animals, particularly frogs, whose embryos
can develop spinal deformities after exposure to
low levels. Dieldrin has been linked to Parkinson's
disease, breast cancer, and classified as
immunotoxic, neurotoxic, with endocrine
disrupting capacity. Dieldrin residues have been
found in air, water, soil, fish, birds, and mammals.
Human exposure to dieldrin primarily derives from
food.
59 Soil Chemistry
5. Endrin
an insecticide sprayed on the leaves of crops,
and used to control rodents. Animals can
metabolize endrin, so fatty tissue accumulation is
not an issue, however the chemical has a long halflife in soil for up to 12 years. Endrin is highly toxic
to aquatic animals and humans as a neurotoxin.
Human exposure results primarily through food.
6. Hexavhlorobenzene (HCB)
was first introduced in 1945–59 to treat
seeds because it can kill fungi on food crops. HCBtreated seed grain consumption is associated with
photosensitive skin lesions, colic, debilitation, and
a metabolic disorder called porphyria turcica,
which can be lethal. Mothers who pass HCB to their
infants through the placenta and breast milk had
limited reproductive success including infant
death. Human exposure is primarily from food.
7. Heptachor
a pesticide primarily used to kill soil insects
and termites, along with cotton insects,
grasshoppers, other crop pests, and malariacarrying mosquitoes. Heptachlor, even at every low
doses has been associated with the decline of
several wild bird populations – Canada
geese and American kestrels. In laboratory tests
have shown high-dose heptachlor as lethal, with
adverse behavioral changes and reduced
reproductive success at low-doses, and is classified
as a possible human carcinogen. Human exposure
primarily results from food.
8. Mirex
an insecticide used against ants and termites
or as a flame retardant in plastics, rubber, and
electrical goods. Mirex is one of the most stable and
persistent pesticides, with a half-life of up to 10
years. Mirex is toxic to several plant, fish
60 Soil Chemistry
and crustacean species, with suggested carcinogenic
capacity in humans. Humans are exposed primarily
through animal meat, fish, and wild game.
9. Toxophene
an insecticide used on cotton, cereal, grain, fruits,
nuts, and vegetables, as well as for tick and mite control
in livestock. Widespread toxaphene use in the US and
chemical persistence, with a half-life of up to 12 years
in soil, results in residual toxaphene in the
environment. Toxaphene is highly toxic to fish, inducing
dramatic weight loss and reduced egg viability. Human
exposure primarily results from food. While human
toxicity to direct toxaphene exposure is low, the
compound is classified as a possible human carcinogen.
10.
Psycholrinated biphenyls (PCBs)
used as heat exchange fluids, in electrical
transformers, and capacitors, and as additives in paint,
carbonless copy paper, and plastics. Persistence varies
with degree of halogenation, an estimated half-life of 10
years. PCBs are toxic to fish at high doses, and
associated with spawning failure at low doses. Human
exposure occurs through food, and is associated with
reproductive failure and immune suppression.
Immediate effects of PCB exposure include
pigmentation of nails and mucous membranes and
swelling of the eyelids, along with fatigue, nausea, and
vomiting. Effects are transgenerational, as the chemical
can persist in a mother’s body for up to 7 years,
resulting in developmental delays and behavioral
problems in her children. Food contamination has led
to large scale PCB exposure.
10. Dichlorodiphenyltrichloroethene (DDT)
is probably the most infamous POP. It was
widely used as insecticide during WWII to protect
against malaria and typhus. After the war, DDT was
used as an agricultural insecticide. In 1962, the
American biologist Rachel Carson published Silent
Spring, describing the impact of DDT spraying on the
61 Soil Chemistry
US environment and human health. DDT’s
persistence in the soil for up to 10–15 years after
application has resulted in widespread and
persistent DDT residues throughout the world
including the arctic, even though it has been banned
or severely restricted in most of the world. DDT is
toxic to many organisms including birds where it is
detrimental to reproduction due to eggshell
thinning. DDT can be detected in foods from all over
the world and food-borne DDT remains the greatest
source of human exposure. Short-term acute effects
of DDT on humans are limited, however long-term
exposure has been associated with chronic health
effects including increased risk of cancer and
diabetes, reduced reproductive success, and
neurological disease.
11. Dioxins
are unintentional by-products of hightemperature processes, such as incomplete
combustion and pesticide production. Dioxins are
typically emitted from the burning of hospital waste,
municipal waste, and hazardous waste, along with
automobile emissions, peat, coal, and wood. Dioxins
have been associated with several adverse effects in
humans, including immune and enzyme
disorders, chloracne, and are classified as a possible
human carcinogen. In laboratory studies of dioxin
effects an increase in birth defects and stillbirths,
and lethal exposure have been associated with the
substances. Food, particularly from animals, is the
principal source of human exposure to dioxins.
12. Polychlorinated Dibensofurans
are by-products of high-temperature
processes, such as
incomplete combustion after waste incineration or
in automobiles, pesticide production,
and polychlorinated biphenyl production.
Structurally similar to dioxins, the two compounds
share toxic effects. Furans persist in the
62 Soil Chemistry
environment and classified as possible human
carcinogens. Human exposure to furans primarily
results from food, particularly animal products.
European Union (EU)
EU Soil Strategy for 2030
The EU Soil Strategy for 2030 is a strategic plan and
measures developed by the European Union with the main
goal of protecting and restoring soils and ensuring that
they are used sustainably. According to the DirectorateGeneral for Environment (2021), it sets a statement that
aims to achieve healthy soil by 2050, with concrete actions
by 2030. Its main objectives are to ensure that by 2050, all
EU soil ecosystems will be healthy and more resilient and
can therefore continue to provide their crucial services.
The framework also aims to reduce net land use and soil
pollution to a certain level so that they are no longer
harming people's health or ecosystems.
The key actions of this framework include notable
strategies that aim to achieve goals by 2050. These actions
are as follows: (1) Tabling a dedicated legislative proposal
on soil health by 2023 to enable the objectives of the EU
soil strategy and achieve good soil health by 2050; (2)
making sustainable soil management the new normal, by
proposing a scheme for land owners to get their soils
tested for free, promoting sustainable soil management
through the CAP and sharing best practices; (3)
considering proposing legally binding objectives to
limit drainage of wetlands and organic soils and to restore
managed and drained peatlands to mitigate and adapt to
63 Soil Chemistry
climate change; (4) investigating streams of excavated
soils and assessing the need and potential for a legally
binding “soil passport” to boost the economy and
enhance reuse of clean soil; (5) restoring degraded soils
and remediating contaminated sites; (6) preventing
desertification by developing a common methodology to
assess desertification and land degradation; (7)
increasing research, data and monitoring on soil; and (8)
mobilising the necessary societal engagement and
financial resources.
United Nations (UN)
There are two major international treaties with
important provisions on soil protection: the 1994 UN
Convention to Combat Desertification and the 1992
Convention on Biological Diversity (UBA, 2015).
1994 UN Convention to Combat Desertification
The Desertification Convention’s major goals are to
combat desertification and minimize the impacts of
drought. When land is degraded or afflicted by drought,
it loses its ability to sustain life, which has a variety of
implications ranging from crop failure to migration and
violence. The United Nations Convention to Combat
Desertification (UNCCD) was founded in 1994 to
conserve and restore our land while also ensuring a
more secure, just, and sustainable future. The
Convention brings together governments, scientists,
policymakers, the commercial sector, and communities
in pursuit of a common goal: to restore and manage the
world’s land. This endeavor is critical to ensuring the
planet’s sustainability and the prosperity of future
generations (UNCCD, 1994).
1992 Convention on Biological Diversity (UBA, 2015)
The Convention on Biological Diversity (CBD) is
concerned with the conservation and sustainable use of
biological diversity, including that found in terrestrial
ecosystems. The goals of this Convention, which will be
followed in conformity with its relevant provisions, are
the conservation of biological diversity, the sustainable
64 Soil Chemistry
use of its components, and the fair and equitable
sharing of the benefits arising from the use of genetic
resources, including through appropriate access to
genetic resources and the transfer of relevant
technologies, taking into account all rights over those
resources and technologies, as well as through
appropriate funding (UN, 1992).
People around the world are facing huge environmental
problems that include climate change, the cutting down of
forests, the turning of land into deserts, pollution, and the loss
of wildlife (Leib, 2011). The environment’s poor condition
affects our health, our way of life, and the natural systems.
The soil is a vital resource for food production, and it
supports the well-being and security of each country.
However, soil pollution is a widespread issue around the
world. Soil pollution has negative impacts on the
environment, human health, food safety, and soil and water
quality (Lu et al., 2015; Zeng et al., 2015; Zhang et al., 2015;
Ma et al., 2016; Rodrigues and Römkens, 2018).
Many industrial activities, uncontrolled waste dumping,
mining, use of agrochemicals, sewage sludge, and livestock
waste, and environmental accidents have resulted in many
sites being polluted (Mirsal, 2008; Li et al., 2017; Cachada et
al., 2018; Gómez-Lavín et al., 2018; Gu et al., 2018; RomeroBaena et al., 2018).
Countries need to have strong laws that provide a legal basis
to stop and deal with soil pollution. Van Liedekerke et al.
(2018) say that “management includes tasks such as setting
up an inventory, investigations, risk assessment and
remediation, and the establishment of recommendations on
land use (restrictions)”. These laws and rules need to be
backed by a clear management framework to guide all those
who are involved in preventing soil pollution, dealing with
old, contaminated sites, and cleaning up new polluted soils.
65 Soil Chemistry
Local Governing Laws
[REPUBLIC ACT NO. 622]
AN ACT CREATING THE BUREAU OF SOIL
CONSERVATION, DEFINING ITS POWERS, DUTIES AND
FUNCTIONS
This law created the Bureau of Soil Conservation,
under the executive control and supervision of the
Department of Agriculture and Natural Resources.
The Bureau of Soil Conservation shall be headed by
the Director of Soil Conservation, to be appointed by the
President. All the divisions, sections, field activities, and
agencies of the government connected with soil
conservation work are hereby transferred to the Bureau of
Soil Conservation, and such powers, functions, and duties
relative to soils vested by law or executive orders are
hereby vested in the Director of Soil Conservation. The
Bureau of Soil Conservation shall investigate properties of
soils in the fields, conduct both reconnaissance and
detailed soil surveys, classify and map soils, undertake
land valuation surveys, formulate water conservation
measures by providing water resources for crop and
livestock production and for farm-life needs, etc.
66 Soil Chemistry
[REPUBLIC ACT NO. 10068]
AN ACT PROVIDING FOR THE DEVELOPMENT AND
PROMOTION OF ORGANIC AGRICULTURE IN THE
PHILIPPINES AND FOR OTHER PURPOSES
The law aims to promote, propagate, further
develop, and implement the practice of organic agriculture
in the Philippines. It will help (a) cumulatively condition
and enrich the fertility of the soil, (b) increase farm
productivity and farmers’ income, (c) reduce pollution and
destruction of the environment, (d) prevent the depletion
of natural resources, (e) encourage the participation of
indigenous organic farmers in promoting their sustainable
practices, (f) further protect the health of farmers and the
general public, (g) save on imported farm inputs, and (h)
promote food self-sufficiency.
It supports sustainable consumption and production
by establishing a comprehensive program for the
promotion of community-based organic agriculture
systems, together with a nationwide educational and
promotional campaign for their use and processing. It also
covers awareness campaigns among consumers about the
benefits of consuming organic food and non-food
products.
[REPUBLIC ACT NO. 11511]
AN ACT AMENDING REPUBLIC ACT NO. 10068 OR THE
ORGANIC AGRICULTURE ACT OF 2010
The law aims to promote, propagate, develop
further, and implement the practice of organic agriculture
in the Philippines that will cumulatively condition and
enrich the fertility of the soil, increase farm productivity
and farmers' incomes, reduce pollution and destruction of
the environment, prevent the depletion of natural
resources, encourage the participation of indigenous
organic farmers in promoting their sustainable practices,
further protect the health of farmers, consumers, and the
67 Soil Chemistry
general public, save on imported farm inputs, and
promote food self-sufficiency.
[REPUBLIC ACT 9003]
ECOLOGICAL SOLID WASTE MANAGEMENT ACT OF
2000
In partnership with stakeholders, the law aims to
adopt a systematic, comprehensive, and ecological solid
waste management program that will ensure the
protection of public health and the environment. The law
ensures proper segregation, collection, storage, treatment,
and disposal of solid waste through the formulation and
adaptation of the best eco-waste products.
[REPUBLIC ACT 6969]
TOXIC SUBSTANCES, HAZARDOUS AND NUCLEAR
WASTE CONTROL ACT OF 1990
The law aims to regulate, restrict, or prohibit the
importation, manufacture, processing, sale, distribution,
use, and disposal of chemical substances and mixtures
that present unreasonable risks to human health. It
likewise prohibits the entry, even in transit, of hazardous
and nuclear wastes and their disposal into the Philippine
territorial limits for whatever purpose; and to provide
advancement and facilitate research and studies on toxic
chemicals.
[PRESIDENTIAL DECREE 1586]
ENVIRONMENTAL IMPACT STATEMENT (EIS)
STATEMENT OF 1978
The Environment Impact Assessment System was
formally established in 1978 with the enactment of
Presidential Decree No. 1586 to facilitate the attainment
68 Soil Chemistry
and maintenance of a rational and orderly balance
between socio-economic development and environmental
protection. EIA is a planning and management tool that
will help the government, decision-makers, proponents,
and affected communities address the negative
consequences or risks to the environment. The process
assures the implementation of environmentally friendly
projects.
[REPUBLIC ACT No. 3082]
AN ACT TO PROVIDE FOR A FIVE-YEAR SOIL SURVEY
AND CONSERVATION PROGRAM
It is known as the Five-Year Soil Survey and
Conservation Act. It’s to protect and conserve soil and
promote wise utilization of soil and water at the earliest
possible time to safeguard the usefulness of those two
vital resources and insure stable farm production, which is
needed for our economy.
This law is to be carried out by the Department of
Agriculture in collaboration with other government
agencies. The program is to do the following: conduct a
soil survey, identify areas with high soil erosion and
degradation, educate farmers and other land users about
the use of appropriate soil conservation practices such as
terracing, contour farming, crop rotation, and crops;
encourage research and development of new soil
conservation technologies and practices; and apply
fertilizer. The Bureau of Soils provides technical
assistance to farmers on how to properly use fertilizer.
Teams to implement the soil survey program in
Luzon, Visayas, and Mindanao will be determined by the
director of soils to be composed of people who can best
accomplish the objective of the soil program and to
include laboratory technicians competent to analyze soil
samples. And the fund of this program is one million pesos
appropriated annually for a period of five years, and the
budget for the five-year program is submitted to the
director of soils, which will be subjected to approval by
69 Soil Chemistry
the secretary of agriculture and natural resources. And
this act was approved on June 17, 1961, and took effect on
January 1, 1962.
[REPUBLIC ACT NO. 7160]
LOCAL GOVERNMENT CODE OF 1991
The code establishes a comprehensive framework
for the governance of provinces, cities, municipalities, and
barangays in the Philippines. Through decentralization, it
aims to enhance the effectiveness of local government
units (LGUs) by delegating increased powers, authority,
responsibilities, and resources. This legislation not only
grants local governments the ability to enact local tax
measures, such as real property taxes, but also ensures
they receive a fair share of the national internal revenue.
Furthermore, the Code emphasizes the importance
of sustainable development by incorporating provisions
that encourage eco-friendly practices and responsible land
use. It underscores the duty of local governments to
pursue initiatives that contribute to environmental
conservation and ecological integrity.
The Code not only defines the powers and
responsibilities of LGUs but also embodies principles of
sustainability, transparency, equity, and adaptability,
contributing to a resilient and responsive local governance
system in the Philippines.
[REPUBLIC ACT No. 7942]
AN ACT TO DISCOURAGE DESTRUCTION OF FORESTS,
FURTHER AMENDING FOR THE PURPOSE SECTION
TWENTY-SEVEN HUNDERD FIFTY-ONE OF THE REVISED
ADMINISTRATIVE CODE.
This act prohibits any person from entering upon
any public forest, proclaimed timberland, communal
forrest, communal pasture, and forest reserve without the
70 Soil Chemistry
written permission of the Directory of Forestry or his duly
authorized representative. In this law it also covers the
prohibition of unlawful “caingin” or in any manner destroy
such forest or part of forest, or to cause any damage to the
timber stand and other forest products and forest growth
found in it.
Violators of this act are fined & imprisoned & the
court shall order the eviction of the offender of the land, &
any forfeiture to the government of any construction or
improvement made thereon.
This law also provides a clear statement that no
person occupied any portion of these forrest in good faith
for more than five years prior June 8, 1939 are subjected
to the penalty prescribed. & should the area so occupied
be found to be more fitted for agricultural than timber
purposes, the same penalty shall be disposed of in favor of
the actual occupant/s.
[REPUBLIC ACT No. 3701]
PHILIPPINE MINING ACT OF 1995
AN ACT INSTITUTIONIZING A NEW SYSTEM OF
MINERAL RESOURCES EXPLORATION, DEVELOPMENT,
UTILIZATION, AND CONSERVATION.
The act governs all mining operations and related
rights in the Philippines, specifically exploration,
development, and utilization of natural resources
conservation through a partnership of the government
and private sector. The act provides that all mineral
resources in lands privately or publicly owned within the
territory and exclusive economic zone of the Republic of
the Philippines are property of the State, which shall
promote and supervise for their rational exploration,
development, utilization, and conservation while
attentively safeguarding the environment and protecting
the rights of affected communities (as ancestral rights).
71 Soil Chemistry
Chapter 6
Engineering Controls
Engineering controls are an essential aspect of workplace safety, particularly in
industries where workers can experience chemical hazards repeatedly. In using this it
can reduce source hazards and improve worker health and safety. Thus, it is essential
to invest in engineering controls to counter chemical hazard risks, improve worker
productivity and ultimately, save costs associated with injury or illness caused by
chemical exposure. By prioritizing engineering control workplaces, we can create a
safer workplace for everyone.
This Chapter Contains:
Responsibilities & Control of Engineers in Soil Chemistry
Possible Duties of an Engineer in Soil Chemistry
Equipment Used in Soil Chemistry
72 Soil Chemistry
Responsibilities and Control of Engineers
in Soil Chemistry
Engineering disciplines that are involved in regulating and
monitoring soil composition in relation to soil chemistry:
•
Agricultural Engineers
Despite their focus in improving agricultural
technologies, agricultural engineers also work on regulating
land pollution, natural resources management and
agricultural production (Indeed Editorial Team, 2023).
Monitoring the soil’s condition and composition is one of
their responsibilities to ensure agricultural productivity
and greater yield.
•
Geotechnical/Soil Engineers
A soil engineer is a professional engineer who
specializes in assessing the properties of the ground upon
which a project is built. It is a critical branch of civil
engineering that deals with the behavior and properties of
earth materials, such as soil and rock. It plays a crucial role
in the design, construction, and maintenance of
infrastructure, ensuring that projects are built on a solid
foundation that can support the intended loads and resist
the stresses imposed by environmental conditions.
73 Soil Chemistry
Possible Duties of an Engineer in Soil
Chemistry
o Analyze soil composition in a specific region.
o Determine soil reactions.
o Conduct laboratory tests to determine soil characteristics
such as acidity, alkalinity and pH levels.
o Consider soil characteristics, especially its weight-bearing
ability, in infrastructure establishment in a certain region.
o Specialize in geotechnical and soil testing equipment.
o Identify elements and minerals abundant in a soil sample.
o Identify specific pollutants such as heavy metals.
o Mitigate the risk of heavy metal and other pollutant
contamination in soils.
74 Soil Chemistry
Equipment Used in Soil Chemistry
Proctor Compaction & Density equipment
is used to determine the optimum moisture and
density of soil. Compaction equipment and molds form
samples to measure the compacted density and unit
weights of soils. Test results are used to control the
placement and compaction of soil embankments and
engineered fills.
California Bearing Ratio (CBR)
equipment for use in the laboratory or field is
available. CBR lab testing determines the moisture
content and strength of laboratory samples. Field tests
measure the strength of soils in place.
Consolidation equipment
tests for soil swell and expansion to predict
the potential for settling under load.
Atterberg Limits products
determine when cohesive soils move
from solid to plastic and liquid phases.
Liquid limit, plastic limit, and shrinkage
limit tests establish the plasticity index, an
important value in foundation design.
Soil Sampling products
are used to profile soil layers and collect
field samples for testing and classification.
75 Soil Chemistry
Permeability testing
or hydraulic conductivity, identifies flow characteristics of
water and other fluids in soils.
Direct/Residual Shear Strength test
equipment
includes pneumatic direct shear, deadweight direct shear, and direct/residual shear
testing machines. These machines measure
the resistance of soils to direct and residual
shear forces. A selection of weight sets, shear
boxes, and other accessories are available for
testing to size, weight, test method, and
standards.
Field Testing/Classification equipment
provides visual and manual
estimates of soil qualities such as moisture
content, strength, density, and grain size.
Soil properties indicate if the soil will be
stable and perform well understructure
and load. Moisture testers, dial and pocket
penetrometers, shear vane sets, classification charts, meters, and
more are used for accurate descriptions.
Hydrometer Analysis of Soils measures
the particle size distribution of silt and
clay in the soil.
Soil Cement test equipment measures the
compressive strength of soil and cement
mixtures. Soil cement is often used as a
base in pavements for its strength.
76 Soil Chemistry
Load Frames
can be equipped for many laboratory soil tests
with a range of digital and analog sets. Load Frames are
used in basic soil tests such as CBR, soil cement, shear
strength, unconfined compression, and more.
Load & Displacement
Measurement
instruments are mounted on load
frames to measure force and deformation
during testing. Grouped sets or individual
components are offered. Select from
analog sets, digital readouts, load cells or
load rings, and more.
Latex Membranes
provide a waterproof barrier to prevent
fluids from leaking into permeability or triaxial
soil specimens during testing.
Porous Stones allow water
drainage and support both ends of a soil
specimen during shear strength, consolidation,
permeability, and triaxial testing.
Data Acquisition Software displays stress and
strain values, computes data, and generates test
reports for many soil and asphalt laboratory
applications. Programs are available for
California bearing ratio/limerock bearing ratio,
triaxial shear, unconfined compressive
strength, soil cement, consolidation,
direct/residual shear testing, and Marshall
stability tests. Software is optimized for use
with two and four-channel digital readout systems.
77 Soil Chemistry
Specimen Measurement tools
provide precise measurements of soil
samples.
Solid Waste Management
Solid Waste
Solid waste refers to any unwanted solid material that can
no longer be used, which is generated due to human and animal
activities and is typically discarded as useless or unwanted.
On the other hand, Waste is a term used to describe
unwanted or useless materials. It can be referred to as rubbish,
trash, refuse, garbage, junk, litter, and ort. In biology, waste is any
of the many unwanted substances or toxins that are expelled from
living organisms, such as metabolic waste like urea and sweat.
Types of Solid Waste
• Municipal Solid wastes
Solid wastes that include household garbage, rubbish,
construction & demolition debris, sanitation residues,
packaging materials, trade refuges etc. are managed by any
municipality.
• Bio-medical wastes
Solid or liquid wastes including containers,
intermediate or end products generated during diagnosis,
treatment & research activities of medical sciences.
• Industrial wastes
78 Soil Chemistry
Liquid and solid wastes that are generated by
manufacturing & processing units of various industries like
chemical, petroleum, coal, metal gas, sanitary & paper etc.
• Agricultural wastes
Wastes generated from farming activities. These
substances are mostly biodegradable.
• Fishery wastes
Wastes generated due to fishery activities. These are
extensively found in coastal & estuarine areas.
• Radioactive wastes
Waste containing radioactive materials. Usually
these are byproducts of nuclear processes. Sometimes
industries that are not directly involved in nuclear
activities, may also produce some radioactive wastes, e.g.
radio-isotopes, chemical sludge etc.
Ways to Reduce Solid Waste
There are many ways to reduce
solid waste. One of the most common
ways to do such is by practicing the
simple “Reduce, Reuse, Recycle”.
These 3 R’s are applied to solid wastes
to manage & address residual solid
wastes.
• Reduction
Is a process that can be redesigned to reduce the
amount of waste generated. It can be done by simply using
paper bags or eco bags instead of plastics.
• Waste Generation
Waste generation encompasses those activities in
which materials are identified as no longer being of value
79 Soil Chemistry
and are either thrown away or gathered together for
disposal. Furthermore, it also includes the simple
segregation of wastes.
• Reuse
Waste may be diverted to reuse. In this process, the
integration of various segregation techniques are applied to
include the Reuse of reusable or returnable materials such
as non-single use plastics, glass bottles, soda & tin cans, &
clothings.
80 Soil Chemistry
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