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close this bookBetter Farming Series 20 - Upland Rice (FAO - INADES, 1977, 30 p.)
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View the documentOrganic manure and chemical fertilizers

Organic manure and chemical fertilizers

32. Organic manures are animal manure and green manure.

Organic manures improve the structure of the soil. Plants grow better in a soil of good structure, and the chemical fertilizers are used better.

Organic manuring should therefore be done at the beginning of the rotation, that is, before growing the first crop on a field.
For example

If in the first year after clearing the field you grow a crop of yams and the second year you grow rice, you must apply organic manure in the first year before you plant your yams.

33. Chemical fertilizers.

You know that the main chemical fertilizers are:

- Nitrogen (N)

- Phosphorus (P)

- Potassium (K)

Rice needs above all nitrogen.

The nitrogen fertilizer most often suitable for the soils of Africa is ammonium sulfate.

But rice also needs phosphorus and potassium. If the rice cannot take out of the soil enough phosphorus and potassium, the stems are not strong and so they bend down to the earth so that the grains cannot form and ripen well.

Ask advice from the extension services in your area. They will tell you how much fertilizer to apply to your rice field.

It is best to apply nitrogen, that is, ammonium sulfate, in three separate applications:

For example

It you have to give your field 100 kilogrammes of ammonium sulfate, apply:

- 40 kg before sowing,

- 30 kg after the first cultivation,

- 30 kg when you see the panicles are forming.

Be careful not to let ammonium sulfate, get onto the leaves; the fertilizer may burn them.

Phosphoric acid and potassium are applied before sowing.