A fortified composite manure at the Kitale ASK Show on October 29, 2016. Fortified composite manure can double crop yield. PHOTO BY LABAN ROBERT.
Farmers, who fortify composite manure, may increase harvests by two-fold as a result of adding the missing mineral components that support a wholesome growth.
Composite manure fortification involves introduction of extra mineral elements into the fertiliser, which is prepared from organic farm waste.
Kenya Agricultural and Livestock Research Organisation officer Jane Kiptoo said the quality and effectiveness of the composite manure is determined by the materials used in the preparation.
Green matters, like legumes, are known for high levels of nitrogen.
“If one uses dry maize remains, which are rich in phosphorus, there is a high possibility that the concentration of nitrogen will be less than the earlier mineral. Other minerals that were used up by the stalks in the formation of the maize grain will be deficient in the composite. This calls for ‘replenishing’ of the minerals,” the officer, who works at the Kitale region, said.
In a cases study published in the International Journal of Science and Nature, African nightshade grown with eight tonnes of composite manure per hectare gave a green leaf harvest of 5.2 tonnes per hectare.
The control experiment field, which was not treated with the composite, gave a yield of 2.6 tonnes of green leaves per hectare.
From the farm composite, every one tonne of the manure was fortifies with 100kg of rock phosphate and 10kg of murate of potash. One kilo of magnesium oxide was added.
The resultant composite had 2.13 per cent nitrogen, 5 per cent potassium, 3.38 per cent phosphorus and 0.57 per cent magnesium. The presence of some minerals can also influence the availability or absence of others.
Because it may not be easy for farmers to know the minerals composition of the various crop residues, Real IPM environmentalist an agronomist said the balance can be reached by sampling. By that, he meant that various farm residues should be used during preparation of the composite.
For instance green potato vines can be mixed with maize husks, weeds, eggs shells, chicken and rabbit waste, peels of tubers and fruits, among others.
Each of the waste will make a contribution of minerals to the composite.
Fortification is done after the composite has turned black, when the pungent smell can no longer be felt. Then the organic fertiliser is left to rest for a while before being used.