By George Munene
By halving inorganic fertiliser use from 75kg of DAP to 35kg per acre and applying manure instead, agronomist Hedmond Morit says he’s helped a maize farmer in Kipkelion, Kericho County move from harvesting an average of 10 bags an acre to a whooping 40 bags.
Some of the 10 acres of double-cob maize yielded up to 46 bags, all the while neighboring farms contending with exorbitant fertiliser prices have had some of their poorest yields in years.
When fertiliser prices hit a record high of over Sh7,000 a bag earlier this year, commercial farmers were left with two options; figure out how to sustain themselves with less or exit farming.
“Biogas slurry harvested from effluent from the farm’s herd of 150 cows is channeled to a drying area. Here it is covered with polythene paper and left to dry for three weeks,” Hedmond explained of the farm’s setup.
Biogas slurry supplies more plant-readily available Nitrogen (N) than other fertilisers. It also increases soil organic matter, and available phosphorus (P) and potassium (K).
It contains trace elements not present in synthetic fertilisers such as manganese (Mn) and selenium (Se), as well as being high in biological pesticides owing to its high number of amino acids, growth hormones, and antibiotics which enhance plant growth.
Bio-slurry is also ideal manure for crops as toxic gases that affect crops are filtered out during anaerobic digestion. This includes methane and sulfur.
The slurry is dried to make it easy to handle and friable. Wet manure can scorch plants if applied directly during planting.
“The farm practices zero tillage/no-till farming–growing crops on pasture without digging. The farmland is sprayed with herbicides to scorch weeds and grass before furrows are dug with a planter,” he outlined.
The manure is left to decompose for two weeks in the furrow bed before planting commences.
Organic manure helps build back the soil in numerous ways; it provides it with humus, therefore, improving soil structure, increasing the number of living organisms within it, stabilising soil acidity; all of which make it more agriculturally conducive.
“The first phase has yielded exceptional results which have been borne out in soil tests which show a gradual increase in the nutritive composition of the soil. We are now eager to see the yield per acre from farming with even less fertiliser application,” the agronomist concluded.