Applying fertilizer deep into the soil allowing the plant to fully absorb the nutrients is assisting rice farmers to increase yields by 18 percent while reducing fertilizer use by one-third.
This is a departure from the traditional broadcasting method done by spreading the fertilizer using hands across a field or paddy which has been blamed for wanton wastage of fertilizer. As prices of fertilizers hit unprecedented highs, with a 50 kg bag of common fertilizers hitting an unprecedented price of over Sh7,000, farmers have been keen on using the minimum amount of fertilizer to achieve maximum results.
But the common broadcast method has been blamed for the wastage of fertilizer with up to 40 percent of all broadcast fertilizer going to waste. The argument is that when fertilizer is broadcast in fields, a huge proportion of Nitrogen, an important component in plant growth, is lost through atmospheric evaporation or conversion to nitrates, compounds that are mobile in the soil and can contaminate groundwater.
But the new method dubbed fertilizer deep placement (FDP) allows the fertilizer to sit deep in the soil releasing nitrogen bit by bit coinciding with the crop’s requirements during the growing season.
Rice farmers using the deep placement technology place the fertilizer compartments between four plants at a depth of seven to ten centimeters within seven days after transplanting.
Soil scientists working with farmers to intensify the uptake of the technology say their analysis has shown that only about five per cent of nitrogen is lost to the environment report that only about 5 percent of nitrogen is lost to the environment compared with about 35 percent when nitrogen is applied through broadcasting. “Within four months of the introduction of the technology, we were able to do a soil nutrient analysis and realized a tremendous improvement in uptake which of course translated into yields,” said Dr. Nathan Mutua one of the scientists working with the farmers.
And farmers are all promises about the technology. “I was a bit skeptical about the technology like most of my fellow farmers. The process of making fertilizer into compartments seemed so tedious. But in two harvests I have managed to get harvests I have never recorded in my 20 years of rice farming,” said Njagi Theuri a rice farmer in Mwea.
The technology which scientists hope to roll out to other crops could be Kenya soil’s holy grail. Kenyan soils have moved from poor to critical as scientists indicate that about 99 percent of Kenyan soils cannot produce tangible yields as they are.
Numerous reports indicate that Kenyan soils acutely lack nitrogen and phosphorus, important nutrients for plant growth.
A study by Farmlight International found that cultivated soil in Kenya suffered an annual net loss of 46 pounds of nitrogen per acre, about 52 kilograms per hectare, removed from the field by harvests. “The beauty with this technology is that because fertilizer sits deep in the soil the soil nutrients stay in the soil for quite some time,” added Dr. Mutua.