|Better Farming Series 17 - Groundnuts (FAO - INADES, 1977, 40 p.)|
36. Groundnuts need above all phosphorus, calcium and sulfur.
The fertilizer called superphosphate contains these in the form of mineral salts.
But different amounts of fertilizers have to be used in different areas, because the soils are not the same. Ask your extension worker what fertilizer to choose and how much of it to apply.
37. To apply too much fertilizer is also a waste of money.
On an experimental field, an application of 75 kilogrammes of superphosphate per hectare resulted in a crop of 1300 kilogrammes of unshelled groundnuts. An application of 150 kilogrammes of superphosphate per hectare yielded a crop of only 1340 kilogrammes. The extra 40 kilogrammes of groundnuts did not pay for the extra 75 kilogrammes of fertilizer used.
Groundnuts can use chemical fertilizers better if you put organic manure on the field before tilling.