Experts pitch for no tillage to curb land degradation

Agricultural experts are lauding the steps Kenyan farmers are making in adopting a no tillage system of farming that increases yileds, but warn that failure to implement the system aggressively and quickly could lead to chronic land degradation and soil erosion that will ultimately threaten food production in the country.

The no tillage system entails planting crops into soil that has remained untilled after the harvest of the previous crop. Such cultivation has proven to have the potential, if carried out in conjunction with other appropriate agronomic practices, to improve food production, cut down labour cost in the farm by up to twenty per cent and stabilise threatened rural livelihoods.

Constant tillage threatens the health of the topsoil, which is paramount for better crop yield since it provides a housing complex for an incredibly diverse community of organisms, including billions of beneficial microbes, nitrogen-fixing fungi, nutrients and earthworms whose digestive tracts transform the fine grains of sterile rock and plant detritus into the fertile excrement that forms soil.

On average, the planet is covered with little more than 3 feet of topsoil. Estimates from the Food and Agriculture Organisation have indicated that the world is losing about one per cent of its topsoil every year to erosion, mostly caused by agriculture.

With scientists insisting that true living topsoil cannot be made overnight as it grows back at a very slow rate of an inch or two over hundreds of years, farmers are being urged to adopt the no tilling method as a means of protecting the topsoil and improving food production.

Some Kenyan farmers plant seed directly into unprepared land immediately after the onset of rains, regarding it as a coping mechanism. Scientists are warning that failure to take up the no tillage system could have serious repercussions for Kenyan agriculture.

The zero tillage system has become a success story in countries where it is being practiced by farmers en masse. In Bangladesh, India and Pakistan, for example, zero tillage has reduced the demand for water in rice and wheat farming on almost a million hectares of land.

While rice and wheat are important for southern Asia's food security, yields had been stagnating and soil quality deteriorating. But a 'rice–wheat' farming system, which has a summer 'wet' crop of rice — during the monsoon season — and a winter 'dry' crop of wheat, gave scientists the leeway to introduce no tillage farming there in 2009.

The wheat seeds germinate in residual water left by the rice crop, saving up to a million litres of water per hectare. This farming technique has been widely hailed for cutting down land degradation by fifty per cent.

All scientists agree that the only problem with the zero tillage system is the over reliance on herbicides, as farmers try to clear weeds in otherwise untilled land which may affect the quality of the crop.

“You see even if you tell farmers to go weed out manually, it is almost impractical for farmers to do it all in their big pieces of land,” says Zipporah Ndeti, another scientist pushing for the adoption of no tillage in Kenya. “We are still looking for innovative and less laborious ways of doing away with weeds. We crack that and zero tillage farming will define farming in Kenya.”