How conservation farming is boosting yields, mitigating effects of climate change

Climate-smart agriculture is key to mitigating the negative effects of global warming. PHOTO | SHUTTERSTOCK

For many years, large-scale and small-scale farmers in the traditional food basket have been planting every season without paying attention to soil health. Over the years, this has resulted in dwindling productivity at the farm level as they grappled with the worst effects of climate change coupled with the high cost of farm inputs.

Kenya’s total land area under maize production is about 1.5 million hectares, with an annual average production estimated at three million metric tonnes, according to data from the Ministry of Agriculture. With declining maize production, Kenya is forced to import to plug the deficit to meet the local consumption.

Experts in the agriculture sector are now championing conservation agriculture to enable food producers and cut costs while attaining higher yields. This practice helps to retain moisture in the soil, ensure minimal disturbance and improve fertility.

Timothy Buisenei, a maize and wheat farmer in Kesses, Uasin Gishu, had been experiencing dwindling yields due to conventional farming until five years ago when he embraced conservation agriculture.

“Previously, production had started to go down, but when we started conservation agriculture, the yields increased,” says Buisenei.

“Maize yields have risen to three tonnes an acre equivalent to about 30 bags of maize but we used to get up to 18 bags. It was even worse for the wheat since we barely harvested 10 bags but now we can get between 18 and 20 bags per acre.”

Conservation agriculture is slowly changing the fortunes of farmers.

“Unlike the conventional method where one uses disc-plough and runs several operations, a farmer uses a special tilling machine in conservation agriculture, meaning you do few operations at a given time.

“Also, there is minimal soil disturbance or burning of the crop stalks or material. This improves micro-organism activity in the soil and buildups organic matter in the soil resulting in better uptake of nutrients by the crops,” says the farmer.

At Komool farm in Soy, Uasin Gishu, the farmer has realised better returns after embracing conservation agriculture in 2012. The farm produces an average of 40 bags per acre of maize compared to 20 in the past.

With the erratic weather patterns, a crop cultivated under conservation agriculture can survive prolonged delays in the rains.

“Sometimes the rains can delay for more than three weeks, but if you compare with the other farms that planted through conventional methods, the crop condition is different because it starts to wilt for lack of adequate moisture in soils,” Rodney Kili tells the Business Daily, adding that with proper management, a plant can also withstand diseases such as fungal infection.

He says this system of farming also cuts production costs such as tilling expenses. Under conventional farming, he says, a farmer ploughs the land three times before planting. Each ploughing costs Sh2,000, meaning a farmer incurs high costs.

“The cost of equipment is a bit expensive but in the long-term single tilling reduces costs due to less fuel.

“A farmer spends Sh2,000 under conservation farming while ploughing under the conventional system costs Sh6,000 per acre,” he says.

Mr Kili adds that farmers must also use certified seeds, proper management from planting to harvesting and the right fertilisers to attain yields.

During the harvest time, crop stalks are left to decompose, allowing the organic matter in the topsoil to build up as well as retaining beneficial organisms in the soil. This improves soil fertility and reduces the need for inorganic fertiliser.

Daniel Chebet, a pomologist (fruit expert) based at the Department of Seeds, Crops and Horticultural Science, University of Eldoret, says the time is ripe to embrace conservation agriculture to boost farm yields due to the adverse effects of climate change and rising costs of farm inputs.

The expert notes that the yields have been declining due to the loss of soil nutrients and hardening of the soil blamed on bad agricultural practices due to the ploughing machines.

“If you look at how farmers plough, it hardens or compacts the soils so that when it rains water does not percolate but there is run-off (assuming that there is plenty of rainfall, which this not the case). But farmers are now able to use the special tillers to break these water pans,” explains the researcher.

Dr Chebet observes that due to the high cost of machinery used mainly by large-scale farmers, their small-scale counterparts can grow Daikon or winter radish or use affordable implements to help to break the hard pan in the soils and boost productivity.

“With the conventional farming, yields decline each year, but it is the other way round with the conservation agriculture — yields rise each year. Today, in Kenya, a farmer can harvest up to three times (and can make Sh80,000 per acre compared to Sh15,000 in a single season),” he says.

Rr Chebet adds that under conservation agriculture, a farmer also practices crop rotation, which breaks the disease cycle in soils.

In countries like the United States, he says, some of the farmers, who started the practice in the 1970s, harvest between 100-136 bags of maize per acre.

Some farms in developed countries have also attained more than 40cm layer of organic matter in soils as a result of conservation agriculture, increasing their yields.

“If you look at conservation agriculture, the organic matter in the soils accumulates over the years, reducing the application rate of inorganic fertiliser. Some may start reducing inorganic fertiliser with time when they have attained 50 to 55 bags.

“However, it is advisable to first conduct a soil test to know the nutrient deficiency in soils,” says Dr Chebet.

Trans Nzoia County agriculture executive Mary Nzomo says conservation agriculture is the best farming practice, especially in the wake of climate change because it not only mitigates the negative effects of global warming but it also reduces production costs by between 30 and 50 percent, translating to better returns for the farmer.

“I know of farmers, especially in drier areas who have registered a 50 percent surge in yields by practising conservation agriculture. Some used to lose entire crops due to drought but now they can cushion their crop from climate change,” she says.

Dr Nzomo says the practice works on three principles — first, permanent soil cover that ensures moisture retention and building up of humus in the soil and second minimal soil disturbance that reduces erosion.

The system also works on the principle of crop rotation that replenishes soil nutrients, especially nitrogen fixation by legumes and reduces exhaustion of nutrients by some heavy feeders such as maize. The idea is to rotate cereals and legumes as well as leave land fallow for some time.

“Given these principles, it is clear that there are multiple benefits for the farmer. This practice is sometimes also called zero or minimum tillage and it is cheaper because you do not do the conventional ploughing. It also utilises some chemical weed control which is cheaper and more efficient,” says the county official.

She argues that this practice is a solution to climate change and in dry areas for the farmers who lose total crop failure.

Already, some counties are practising conservation agriculture such as Trans Nzoia, which has bought special equipment for farmers to hire, says Dr Nzomo.

“The special equipment used to break the soil hard pan ensures the moisture is retained in the soil to support plant growth and development,” the official notes.

Wilbur Mutai, agricultural projects official at the Uasin Gishu County government, says a majority of farmers in the region had been worst hit by the negative effects of climate change.

“We have witnessed a reduction in the crop production on the farm, there is rain and emergence of new pests and diseases like fall armyworm and migratory locusts due to the rising temperatures.

“We are encouraging our farmers to change to adapt to the new techniques to cope with climate change,” said the county official.

Mr Mutai explains that the devolved unit promotes climate-smart agricultural activities to allow farmers to adopt eco-friendly practices to mitigate the impact of climate change.

“We are engaging our farmers to adopt green technologies and get the right tree species of their farm and to protect riparian land by ensuring that they don’t cultivate 30 metres from the river to protect riparian lands,” said Mr Mutai when he recently spoke to 3,000 smallholder farmers in Uasin Gishu County who benefited in the greening initiative to boost forest cover, promote conservation agriculture and protect the water catchment areas.

He said the county had partnered with Micro-Enterprises Support Programme Trust to distribute 4,500 indigenous and fruit tree seedlings to boost climate-smart agriculture through the initiative.

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