After studying this chapter you will be able to understand: Mutualistic relationships between plant roots and the bacteria and fungi that grow in the rhizosphere help plants acquire important nutrients; nonmutualistic nutritional adaptations enable plant survival in adverse habitats. | Ch. 37 Warm-Up What conclusions should we draw from van Helmont’s experiment? Where would you expect a deficiency of a relatively immobile element to be seen first in a plant? (pg. 756) What are the possible consequences of selling off water rights to cities and developments? Chapter 37 Plant Nutrition What you need to know: Mutualistic relationships between plant roots and the bacteria and fungi that grow in the rhizosphere help plants acquire important nutrients. Nonmutualistic nutritional adaptations enable plant survival in adverse habitats. Nutritional Requirements Essential element: required for plant to complete life cycle and produce another generation Macronutrients (large amounts): CHNOPS + K, Ca, Mg Nitrogen = most important! Micronutrients (small amounts): Fe, Mn, Zn, Cu, etc. Soil Quality Texture – topsoil w/ humus (decayed organic material) prevents packing of clay porous (retain H2O) yet aeration of roots Chemical composition cation exchange: roots add H+ to soil to replace cations (K+, Ca2+, Mg2+) absorbed by plant Soil particle surrounded by film of water Root hair Water available to plant Root hair Air space Cation exchange in soil Soil water Soil particle Availability of soil water and minerals Mutualistic Relationships: Rhizobium bacteria supply nitrogen at roots (fix atmospheric N2 to usable N) Plant supplies sugar & amino acids Mycorrhizae (plant + fungus) Role of soil bacteria in the nitrogen nutrition of plants Unusual nutritional adaptations: epiphytes, parasitic plants, canivorous plants Epiphyte: grow on another plant, absorb H2O from rain through leaves Parasitic Plants: not photosynthetic; absorb sugar and minerals from living hosts Carnivorous Plants: photosynthetic, but obtain some nitrogen and minerals by digesting small . | Ch. 37 Warm-Up What conclusions should we draw from van Helmont’s experiment? Where would you expect a deficiency of a relatively immobile element to be seen first in a plant? (pg. 756) What are the possible consequences of selling off water rights to cities and developments? Chapter 37 Plant Nutrition What you need to know: Mutualistic relationships between plant roots and the bacteria and fungi that grow in the rhizosphere help plants acquire important nutrients. Nonmutualistic nutritional adaptations enable plant survival in adverse habitats. Nutritional Requirements Essential element: required for plant to complete life cycle and produce another generation Macronutrients (large amounts): CHNOPS + K, Ca, Mg Nitrogen = most important! Micronutrients (small amounts): Fe, Mn, Zn, Cu, etc. Soil Quality Texture – topsoil w/ humus (decayed organic material) prevents packing of clay porous (retain H2O) yet aeration of roots Chemical composition cation exchange: roots add H+ to soil to replace cations (K+, Ca2+, Mg2+) absorbed by plant Soil particle surrounded by film of water Root hair Water available to plant Root hair Air space Cation exchange in soil Soil water Soil particle Availability of soil water and minerals Mutualistic Relationships: Rhizobium bacteria supply nitrogen at roots (fix atmospheric N2 to usable N) Plant supplies sugar & amino acids Mycorrhizae (plant + fungus) Role of soil bacteria in the nitrogen nutrition of plants Unusual nutritional adaptations: epiphytes, parasitic plants, canivorous plants Epiphyte: grow on another plant, absorb H2O from rain through leaves Parasitic Plants: not photosynthetic; absorb sugar and minerals from living hosts Carnivorous Plants: photosynthetic, but obtain some nitrogen and minerals by digesting small animals
