Plant Nutrition AP Biology 2006 2007 Physiological adaptation

Plant Nutrition AP Biology 2006 -2007

Physiological adaptation Dogs pee on trees…Why don’t trees pee on dogs? NH 3 animal waste AP Biology plant nutrient

Nutritional needs § Autotrophic does not mean autonomous u plants need… § sun as an energy source § inorganic compounds as raw materials w water (H 2 O) w CO 2 w minerals AP Biology

Macronutrients § Plants require these nutrients in relatively large amounts u AP Biology C, O, H, N, P, K, Ca, Mg, S

For what & from where? C macromolecule synthesis CO 2 O macromolecule synthesis CO 2 H macromolecule synthesis & proton pumps H 2 O N protein & nucleic acid synthesis soil P nucleic acids, ATP, phospholipids soil K stomate control, water balance soil Ca cell wall & membrane structure, regulation soil Mg chlorophyll soil S proteins, enzymes soil AP Biology

Micronutrients § Plants require in very small amounts Cl, Fe, Mn, Bo, Zi, Ni, Mb u primarily cofactors for enzyme function u AP Biology

Nutrient deficiencies § Lack of essential nutrients u exhibit specific symptoms § dependent on function of nutrient § dependent on solubility of nutrient AP Biology

Magnesium deficiency § Symptoms Take 2 fertilizer pellets & call me in the morning chlorosis = yellowing of leaves u Why? What is magnesium’s function? u AP Biology

Chlorophyll Why does magnesium deficiency cause chlorosis? The chlorosis shows up in older leaves first, because plant moves + to newer leaves. Why? Mg AP Biology

Agronomists really dig dirt! The role of soils § Plants are dependent on soil quality u texture / structure § relative amounts of various sizes of soil particles u composition § organic & inorganic chemical components § fertility AP Biology

Importance of organic matter § Topsoil most important to plant growth u rich in organic matter u So don’t rake your lawn or bag your leaves § humus w decomposing organic material breakdown of dead organisms, feces, fallen leaves & other organic refuse by bacteria & fungi w improves soil texture w reservoir of minerals n u organisms § 1 tsp. of topsoil has ~5 billion bacteria living with fungi, algae, protists, insects, earthworms, nematodes AP Biology

Soil health as a global issue Not taking care of soil health has far-reaching, damaging consequences 1920’s Dust Bowl u lack of soil conservation u § growing the same crop year after year (wheat) § grazing by cattle § bare ground exposed to wind erosion in winter § drought AP Biology

Fertilizers § “Organic” fertilizers u manure, compost, fishmeal § “Chemical” fertilizers commercially manufactured u N-P-K (ex. 15 -10 -5) u § 15% nitrogen § 10% phosphorus § 5% potassium AP Biology What are the political, economic, environmental issues?

Nitrogen uptake § Nitrates plants can only take up nitrate (NO 3 -) § Nitrogen cycle by bacteria u trace path of nitrogen fixation! u root AP Biology What will the plant use N for?

Soybean root nodules § N fixation by Rhizobium bacteria u AP Biology symbiotic relationship with bean family (legumes)

Plow it under? Why would you that? Increasing soil fertility § Cover crops u growing a field of plants just to plow them under § usually a legume crop § taking care of soil’s health w puts nitrogen back in soil AP Biology A farmer… outstanding in his field? erosion control, too

Some plant oddities… AP Biology 2006 -2007

Parasitic plants § tap into host plant vascular system Indian pipe Mistletoe AP Biology

Plants of peat bogs § High acid environment u most minerals & nutrients bound up & are not available to plants § must find alternative sources of nutrients AP Biology

Carnivorous plants Sundew Venus fly trap Pitcher plant Are they really carnivores? AP Biology

AP Biology Pitcher plant

Any Questions? ? AP Biology 2006 -2007

Local Long Island soil issues Quartz silica based soils - low in P - can be acid Acid soils bind up mineral ions p. H by adding lime AP Biology Granite

Soil health as a global issue § Soil conservation & sustainable agriculture u u u maintaining healthy environment sustainable production of food supply economically viable farming industry “A sustainable agriculture does not deplete soils or people. ” – Wendell Berry contour plowing AP Biology cover crops crop rotation

Global issues § soil fertility § erosion § irrigation § forestry destruction AP Biology

AP Biology

Uses of peat AP Biology