Jan Baptista Van Helmont
His willow tree experiment "proved" that water was the sole nutrient of plants.
Sir Frances Bacon
Believed: - water = principle plant nourishment - soil = kept plant upright and insulated from extreme temperature
John Woodward
Plant growth is influenced by something other than water
Jethro Tull
Roots ingest soil particles & cultivation made it easier for plants to take up soil
de Saussure
- The soil provides only small amounts of nutrients required by plants - Plants obtain C from the air - The increase in mass of the plant as it grows could not be due only to uptake of CO2, but also to the uptake of H
de Saussure
he outlined the basic reaction by which Plants convert CO2 and water to glucose
Humus theory
plants live on humus-derived extracts (C, H, O, N) from which they are able to rebuild more complex plant tissue
Albrecht Thaer
he believed the Humus theory
Albrecht Thaer
he believed that An internal vital force of plants allows to generate other vital nutrients from four elements in humus -
Albrecht Thaer
he believed Fertilizer salts and lime good b/c promote humus and OM breakdown
Philip Carl Sprengel
a student of Thaer
Philip Carl Sprengel
Came up with a list of compounds required for plant growth and discussed the idea of fertilizers
Philip Carl Sprengel
he stated the law of minimum
Ca, Mg, K or alkali metals
were needed to neutralize acids formed by plants
Phosphates
are needed to neutralize acids formed by plants
Justus von Liebig
Laid the foundation for the modern fertilizer industry
P and K with lime
He manufactured fertilizer but made the mistake of fusing with what elements
Justus von Liebig
he popularized the law of minimum
Nickel
latest discovered essential elements
Jethro Tull
. He wrote the book “Horse and Hoeing Husbandry” and developed the horse hoe and the seed drill.
Pietro de Crescenzi
published a book on agricultural practices.
Marl
during the greek period this was used to increased productivity of soils or as a liming material
Taste test
during the greek period saline soils were tasted using
Shifting cultivation
refers to any temporal and spatially cyclical agricultural system that involves clearing of land—usually with the assistance of fire— followed by phases of cultivation and fallow periods