Mineral Nutrients in Soils and Plants Flashcards
Material composition of plants…
90% is water, rest mostly C, O and H
What nutrients do plants require?
C, H, O, K, N, Ca, Mg, P, S, Fe, Mn, Zn, Cu, Ma, Cl and B
Excamples of plants requriing special nutrients?
Nitrogen fixators and cobalt and nickel
Plant element accumulation phytoremediations…
Grown, harvested, dried, incubated and ash disposed
What elements are toxic in plants?
Al and Mn in acidic soils, Na and Cl in saline soils
Foliar Uptake
A process of diffusion, depending on cuticle permeability and concentration gradients
How do plants absorb gas?
Green tissues by foliar uptake, mostly roots
Root nutrient absorption…
Roots to the vascular system, most effectively done at the tip, whilst less so beyond with formation of the endothermis, seperating conductive tissues and roots
What allows plants to overaccumulate nutrients?
Photosynthetic product breakdown, limited by cold or O2
Nutrient transport within plants?
Zylen transports to shoot by mass flow, after delivery to growing shoots, reabsorbed from xylem fluid and assimilated
Function of the phloem…
Mediates re-translocation from older to younger tissues: N and S readily mobilised as protein
Importance of nutrients stored in organiac complexes?
Leaching would othersiw deplete soil of nutrients
CEC/SOM decay in nutrient release?
CEC rapid whilst SOM slow
What do release rate and solution concentration depend on?
Amounts/kinds of solid-phase nutrients, soil water content, temperature, aeration, microbial activities and soil solution properties
CEC Hydrated cations…
Most readily exchangeable
