Theory question 104
Soil Fertility and Plant Nutrition(a)(i) State six uses of lime in agriculture. (ii) List four common liming materials.
(b) State: (i) three examples of a nitrogenous fertilizer. (ii) three examples of a phosphorus fertilizer.
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(a)(i) Any six: corrects soil acidity (raises pH); supplies calcium (and magnesium); improves soil structure (flocculates clay); increases availability of nutrients such as phosphorus; encourages activity of soil micro-organisms and nitrogen fixation; reduces toxicity of aluminium/manganese/iron; used in fish ponds to correct acidity; used as disinfectant in animal houses
(ii) Any four: ground limestone (calcium carbonate); quick lime (calcium oxide); slaked/hydrated lime (calcium hydroxide); dolomite; marl; wood ash; basic slag
(b)(i) Any three: urea; ammonium sulphate (sulphate of ammonia); ammonium nitrate; calcium ammonium nitrate; sodium nitrate; anhydrous ammonia
(ii) Any three: single superphosphate; triple superphosphate; rock phosphate; basic slag; bone meal; ammonium phosphate
Simple lists; give chemical names where you can.