Chapter 29 Plant Nutrition and Soil Sun, Water, Nutrients necessary CO2 and H20 into organic compounds Synthesize all required amino acids, vitamins, using inorganic nutrients from environment. Evolution designed for efficient uptake of raw material and distribution

Plant Nutrition and soil Essential Elements Functions of Essential Elements The soil Nutrient cycles Nitrogen and Nitrogen cycle The Phosphorus Cycle

Nitrogen cycle

Plant Nutrition and Soils Plant Nutrition- involves the uptake from the envrionment of all the raw material required for 1.Essential biochemical processes (metabolism and growth) 2.Distribution within the plant More than 60 chemical elements identified Not all essential (gold, silver, lead, mercury, arsenic, uranium) Phytoremediation- the removal of contaminants

The fungus Boletus parasiticus Forms Ectomycorrhizae on the Roots of a red pine (Pinus resinosa) Increase uptake of water and Phophorus Also Protects against pathogenic Fungi and nematodes

Essential Elements Criteria Needed for life cycle and/or Essential for parts i.e. Mg in chlorophyll Nitrogen in protein 17 essential

Essential elements Necessary for plant growth In the absence plant displayed characteristic abnormalities of growth, or deficiency symptoms, reproduction In 1880 established that at least 10 essential Essential elements/minerals (inorganic nutrients)- Carbon, hydrogen, oxygen, potassium, calcium, magnesium, nitrogen, phosphorus, sulfur and iron By the 1950’s added seven more, manganese, zinc, copper, chlorine, boron, molybdenum, and nickel

The essential elements can be divided into Micronutrients and Macronutrients Micronutrients- trace elements equal or less than 100 mg/kg Macronutrients – require large amounts above 100 mg/kg Nutrient sometimes greater in conc. Than soil thus have to use energy Certain plant species are chars. By specific elements

Plants of the mustard family i.e. Wintercress use sulfur Synth. Mustard oil

Horsetail silicon into cell walls Making it indigestible for herbivores

Functions of Essential Elements Essential elements: Functions and Defieciency symptoms Table 29-2

Nutrient Deficiency symptoms Depend on functions and mobility of essential elements Chlorosis Fig loss or reduced development of chlorophyll Magnesium, essential for chlorophyll –Younger leaves vs. older leaves –Depends on phloem –Phosphorus, potassium and nitrogen are also phloem- mobile (appear in older first) –Iron and calcium are phloem immobile (appear in younger first) –Sulfur and zinc intermediate in mobility

Deficiency of magnesisum a phloem mobile element in Maise- older leaves more affected than younger

Sorghum - Deficiency of iron a so called phloem immobile element results in symptoms of chlorosis in younger leaves

The soil

Fibrous roots that bind and anchor prairie soil Primary nutrient medium for plants Root systems (fibrous anchor) Weathering of rock produce the inorganic nutrients

Three major soil types Coniferous- acidic little accumulation of humus is leached of minerals Cool temperate deciduous decay is more rapid, leaching less, soil more fertile Grasslands, almost all plant dies each year organic material returned to soil- highly fertile soil, often black in color

Soil consist of layers called Horizons

Living organisms of the A horizon Microbes, small mammals, earthworms Ants