Posted on March, 3, 2022 at 08:41 am
Soil fertility in the country is declining due to insufficient nutrients, scientists have said.
They have warned that soil fertility depletion is the fundamental cause of declining per capita production.
This, scientists say, is arising from continuous mining of soil nutrients and inappropriate farming practices, including the use of blanket fertiliser recommendations.
Kenya Agriculture and Livestock Research Organisation director general Dr Eliud Kireger said nutrient depletion varies with the intensity of field management, soil properties and landscape.
“Some of the negative effects of land degradation include decline in crop productivity, food insecurity, low returns on agricultural investment and environmental degradation,” he said.
Kireger spoke on Wednesday during a farmers’ field day in Ainamoi ward, Kericho.
He said fertiliser trials conducted by KARI (now KALRO) in 1994 in 37 counties showed that major soil nutrients–nitrogen and phosphorus–, were deficient in 57 per cent and 26 per cent respectively.
“For example, most farmers apply fertiliser to increase their banana yield at average rates of 20kg per acre of inorganic fertiliser and about 40kg per acre of dried organic manure," Kireger said.
However, these amounts are quite low compared to the national average of 55kg of fertiliser per acre and way below recommended rates of 80kg per acre of DAP, or 60kg per acre of NPK (23:23:0) at planting,” he said.
Kireger said traditional approaches towards soil fertility replenishment, including organic farming and low external input, have failed due to low availability of inputs by smallholders, leading to land degradation.
KALRO has been undertaking soil fertility replenishment strategy based on integrated soil fertility management (ISFM) practices which advocate the use of both organic and inorganic fertilisers for balanced nutrient fertilisation.
“This calls for precise and prescriptive fertiliser recommendations at the farm level which are based on precise soil testing to ensure increased, sustainable and profitable crop production. Thus, for increased and sustainable crop production, appropriate fertiliser recommendations based on soil tests are paramount,” Kireger said.
“Adoption of innovative soil testing techniques that are rapid with a high output will help increase sustainable food production and hence food security.”
Esther Gikonyo, a soil fertility and plant nutrition scientist at KALRO – Kabete, said soil fertility in the country is declining.
This is due to continuous cropping without sufficient application of nutrients and proper management of the soils, which leads to soil degradation.
“For us to improve crop production, we need to look at the management of soils for 10 years to be able to be food secure,” she said.
The scientist said they are working in five counties–Bomet, Kericho, Machakos, Nyandarua and Nyeri–under the soil fertility replenishment strategy.
“In Bomet, Kericho, we are doing soil testing on banana production, pigeon pea and green grams varieties in Machakos and Irish potato in Nyandarua and Nyeri. In all of these counties the basic thing we are looking at is how we can improve soil fertility because that is the basis of crop production," Gikonyo said.
"You cannot manage what you do not understand or rather, what you do not know and therefore, for us to be able to manage the soils, we have to do soil testing.”
Source: The Star