350 300 70.5170 Frequency 250 200 150 100 50 0 50 60 70 80 90 100 110 Index value 120 130 140 150 Soil and mineral nutrition • Soil is a complex product of the interaction between living organisms and their terrestrial environment • Soils are very heterogeneous • Soil texture describes the relative contribution of particle with different sizes that impart different characteristics and affect plant performance • Most plants depend on soil to obtain water and mineral nutrition • The pH of soil is an important characteristic that affects nutrient intake • Essential nutrients are indispensable for plant growth and reproduction • Most plants depend on mycorrhizae (symbiotic relationships with fungi) to increase phosphorus and other minerals from the soil Adventitious roots (develop from stems) Fibrous root taproot enlarging radicle, or embryonic root Stem x.s. of Lycopersicon (tomato) http://www.uri.edu/artsci/bio/plant_anatomy/images.html#lab_10 Contain suberin, a fatty waterproof material Water enters by osmosis Nutrient minerals enter by passing through carrier proteins in the membranes Root x.s. of Zea mays (corn) Epidermis Cortex cell Endodermis Pericycle cell Pith cell Xylem vessel element Phloem cell http://www.uri.edu/artsci/bio/plant_anatomy/images.html#lab_10 Soil is composed of • • • • Inorganic mineral particles Organic matter Water Air The texture, or structural characteristic of a soil is determined by the percentages (by weight) of the differentsized inorganic mineral particles -sand (0.02-2 mm), silt (0.002-0.02 mm), and clay (<0.002 mm), - A loam: 40 % sand, 40 % silt, and 20 % clay Igneous rocks http://cmsc.minotstateu.edu/Labs/rockslab/igneous/igneousbox.html Metamorphic rocks http://cmsc.minotstateu.edu/Labs/rockslab/metamorphic/metamorphicbox.html Sedimentary rocks http://cmsc.minotstateu.edu/Labs/rockslab/sedimentary/sedimentarybox.html PreSettlement Soils Extant Habitats White Sands Archbold St. Lucie Yellow Sands Astatula Candler Lake Orsino Paola Tavares Grey Sands Satellite N This map was created at the Archbold Biological Station Geographic Information System Laboratory. Roberta Pickert 1999 0 50 100 km Kilom eters 0 25 50 75 100 Prepared by: Roberta L. Pickert. 9 December 1999 www.archbold-station.org Elements required by plants (macronutrients, >0.05% dry weight) Carbon CO2 carbohydrates ,lipids, proteins and nucleic acids Hydrogen H2O carbohydrates ,lipids, proteins and nucleic acids Oxygen H2O, CO2 carbohydrates ,lipids, proteins and nucleic acids Nitrogen NO3, NH4 proteins, nucleic acids, and chlorophyll Potassium K osmotic and ionic balance Calcium Ca2 in cell walls; membrane permeability 2 Magnesium Mg chlorophyll; 2 Phosphorus HPO4 , Sulfur H2PO4 SO42 nucleic acids, ATP, phospholipids Aminoacids Silicon SiO32 in cell walls Table 34-2 pp. 744 Elements required by plants (micronutrients, <0.05% dry weight) • Chlorine, Iron, Boron, Manganese, Sodium, Zinc, Copper, Nickel, Molybdenum • Parts of enzymes and Ionic balance. Table 34-2 pp. 744 Nitrogen fixing bacteria, Azotobacter (ae) and Clostridium (an) Plant proteins Nitrogen wastes Gain from atmosphere Nitrates, NO3 Animal proteins Decay bacteria and Fungi Nitrifying bacteria Ammonium NH4 Ammonia Loss to Atmosphere Denitrifying bacteria Denitrifying bacteria e.g. Nitrobacter e.g. Nitrosomonas Nitrites, NO2 The Nitrogen Cycle Endophytes: Legume/Rhizobium nodules Leghaemoglobin sequesters oxygen and creates a low oxygen environment http://www.botany.hawaii.edu/faculty/webb/BOT410/Roots/RootSymbioses.htm Occurs in 90 % of all plant families Above: Ectomycorrhyzae Below: Endomycorrhyzae MOORE-LANDECKER. 1990. FUNDAMENTALS OF THE FUNGI. PRENTICE HALL. ENGLEWOOD CLIFFS. Pp. 481, fig. 15-9; 483, fig. 15-10 Total mass (g) of mycorrhyzae present absent Andropogon gerardii 89 66 Sorghastrum nutans 121 62 Wilson and Hartnett. American Journal of Botany 84 No, 4, 1997 Arbuscular Mycorrhizae epidermis Cross-section of Ranunculus root (buttercup) cortex stele immature Notice numerous amyloplasts which store starch Mature http://www.uri.edu/artsci/bio/plant_anatomy/images.html#lab_10 Close up of Cross-section of Ranunculus root Intercellular spaces immature Cortex cells Endodermis cells Pericycle cells Phloem cells Xylem vessel element http://www.uri.edu/artsci/bio/plant_anatomy/images.html#lab_10 Mature Cation exchange Neutral pH near 7 Acid pH, 4-5