Kenya farmers heal soils, increase yields with conservation agriculture
At a time when tired soils and drought as a result of weather changes have left agricultural land barren, a new low-cost farming method is restoring hope among over thousands of farmers in Kenya by increasing yields and restoring soil health.
Dubbed conservation agriculture, CA, the initiative is also intensifying food production and boosting earnings for smallholder farmers in Kenya. It involves practices such as minimum soil disturbance, crop residue retention and intercropping.
While most Kenyan farmers plant seed directly into unprepared land immediately after the onset of rains terming it a coping mechanism, no-tillage cultivation has proven to have the potential – if carried out in conjunction with other appropriate agronomic practices – to become an important part of strategies to improve food production, cut down labour cost in the farm by up to 20 percent and stabilize threatened rural livelihoods.
Traditionally, farmers till land to kill weeds and make soil crumble. But plowed dirt can wash or blow away. Tilling also exposes lower layers of earth to sunlight, evaporating moisture and burning nutrients. For example, 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.
For Mary Munene, a farmer from Murang’a, the idea of preparing her land by spraying herbicide – as opposed to plowing the fields prior to planting – sounded too simplistic to be believed. Throughout her farming life she had adopted the traditional methods like tilling.
Through trainings by research institutions like Kenya Agricultural and Livestock Research Organization, KALRO, she learned the importance of minimal soil disturbance and to dig holes only where seeds were to be planted to reduce soil erosion. She also learned how to space her maize and legume seeds to optimize yields, as well as the correct application rates for manure and fertilizer to improve soil nutrient levels.
“People thought we were crazy when they saw us spraying our land and they warned us that we would damage our soils and get no harvest,” says Mary. But, in spite of her scepticism, she set aside 1 acre of her 2.5 acre farm to test the CA-based practices. From the first harvest after adopting the practice, Mary obtained 8 bags of produce, where previously, she would harvest just three bags. Following these promising results, Mary was conscious to apply the advised rates of manure and fertilizer when preparing her land for the next season and increased her harvest again to 14 bags. “My yields keep on increasing!” she exclaims.
Mary has also joined an ‘innovation platform’ (agricultural knowledge exchange and action forum). Being a part of 30-member group has enabled her to afford inputs like herbicide, fertilizer and improved seeds at discounted prices as the group is able to buy in bulk collectively. According to Mary, the use of quality inputs has not only improved her yields, but has saved her time, labor and expense. Prior to embracing CA, Mary would spend Ksh 6,000 on plowing services, but since using herbicides, she spends just Ksh2,000 per acre.
In using sustainable intensification practices, productivity is increased without compromising the ability of the environment to meet the needs of future generations.
As part of the innovation platform, group marketing has also enabled Mary to achieve a higher price for her produce. Before joining the group, she would sell a bag of kales for around Sh2,800, but since bulk selling with the group, she is able to receive higher prices of between KSH 4,000-6,000 With her increased earnings, Mary has also improved her nutrition security through the purchase of chickens to provide eggs for household consumption. She has also bought an Ayshire heifer, from which she aims to produce and sell milk to further increase her earnings.
Derreck Rono a maize farmer in Trans Nzoia County, one of Kenya’s breadbasket had never known peace. With his one acre piece of land sitting on a sloppy terrain, he welcomed and dreaded the long rains in equal measure. For even though he needed them for his crop’s growth, it was only a matter of time before the top soil together with his crops would be washed away. He couldn’t relocate, so he decided to do something about it. Instead of plowing before each planting, he leveled the previous crop, let the residue decompose and seeded the following year’s crop directly in the mulchy remains.
The runoff stopped, and within two years, the farm had a layer of topsoil that “now grows whatever you plant,” said Rono. Whereas the land initially 50 kilograms, of maize an acre, the farm – now two acres – last year produced 200 kilograms of maize an acre, plus other crops including beans, and horticultural produce.
Zero-tillage farming with residue cover saves irrigation water, gradually increases soil organic matter and suppresses weeds, as well as reduces costs of machinery, fuel and time associated with tilling. Leaving the soil undisturbed increases water infiltration, holds soil moisture and helps to prevent topsoil erosion. Conservation agriculture enhances water intake that allows for more stable yields in the midst of weather extremes exacerbated by climate change.
While conservation agriculture provides many benefits for farmers and the environment, farmers can face constraints to adopt these practices. Wetlands or soils with poor drainage can make adoption challenging. When crop residues are limited, farmers tend to use them for fodder first, so there might not be enough residues for the soil cover. To initiate conservation agriculture, appropriate seeders are necessary, and these may not be available or affordable to all farmers. Conservation agriculture is also knowledge intensive and not all farmers may have access to the knowledge and training required on how to practice conservation agriculture. Finally, conservation agriculture increases yields over time but farmers may not see yield benefits immediately.
