Conservation agriculture transforming farming in Southern Africa

By Guardian Correspondent , The Guardian
Published at 08:20 AM Dec 07 2024
Christian Thierfelder, Principal Scientist at CIMMYT, poses in a field that is being tested for conservation agriculture at Henderson Research Station, Harare, Zimbabwe. Credit, Busani Bafana
Photo: IPS
Christian Thierfelder, Principal Scientist at CIMMYT, poses in a field that is being tested for conservation agriculture at Henderson Research Station, Harare, Zimbabwe. Credit, Busani Bafana

ON the dusty plains of Shamva District in Zimbabwe, Wilfred Mudavanhu's maize field defies drought.

With the El Niño-induced drought gripping several countries in Southern Africa, Mudavanhu’s maize crop is flourishing, thanks to an innovative farming method that helps keep moisture in the soil and promotes soil health.

Once harvesting just 1.5 tonnes of maize (30-50 kg bags) each season, Mudavanhu’s harvest jumped to 2.5 tonnes of maize (50 bags) in the 2023/2024 cropping season.

Mudavanhu is one of many farmers in Zimbabwe embracing conservation agriculture, a method that prioritizes minimal soil disturbance, crop rotation, and soil moisture conservation. The practice is complemented by other methods such as timely control of weeds, mulching, and farming on a small plot to gain high yields.

Researchers say the conservation agriculture method is proving a lifeline for farmers grappling with climate change.

For more than 20 years, the International Maize and Wheat Improvement Center (CIMMYT) has promoted research on conservation agriculture in Southern Africa with the aim of getting farmers to increase their crop yields.

Under conventional farming, smallholder maize yields have often been below 1 tonne per hectare in Zimbabwe, according to researchers. Adopting CA practices has led to yield increases of up to 90 percent. 

While in Malawi farmers have experienced maize yields increased by up to 400 percent, crops are integrated with nitrogen-fixing trees such as Faidherbia albida. In Zambia, maize yields under conventional farming have been at 1.9 tonnes per hectare, and these have increased to 4.7 tonnes per hectare where farmers have used conservation agriculture practices.

But beyond high yields, conservation agriculture saves moisture and enhances soil health, offering farmers a long-term solution to the growing problem of soil degradation, a looming threat in the face of climate change, researchers said.

“As the climate crisis deepens, CA has become essential for Southern African farmers, offering a resilient, climate-smart approach to boost productivity and withstand climate change impacts, reinforcing sustainable food security,” Christian Thierfelder, a principal scientist at CIMMYT, told IPS, explaining that CA could be a game changer for the rainfed cropping system in the region.

About 3 million farmers in Southern Africa are practicing CA, Thierfelder said, adding: “The more climate change hits as seen in recent droughts, the more the farmers will adopt CA because the traditional way of doing agriculture will not always work anymore.”

The use of machines is attracting smallholder farmers to adopt conservation agriculture. CIMMYT has researched using machines suitable for smallholder CA systems.

The machines have been found to increase intercropping methods farmers use while addressing the challenges of high labour demands associated with conservation agriculture.

Traditionally, farmers spend hours digging planting basins, a time-consuming and labor-intensive process. The basin digger has mechanized the land preparation stage, reducing the number of people needed to dig the basins.

Thierfelder said CIMMYT has partnered with registered service providers in Zimbabwe and Zambia, who offer mechanization services that improve farming efficiency and reduce labour demands. One such innovation, the basin digger—a cost-effective, low-energy machine—reduces labour by up to 90 percent.

Cosmas Chari, a farmer and service provider in Shamva, used to spend a day digging basins for planting, but now he takes an hour using the basin digger.

Mudavanhu became a mechanization service provider after integrating CA with mechanization. As a service provider, Mudavanhu hires out a two-wheeled tractor, a sheller, and a ripper to other farmers practicing CA.

Similarly, another farmer, Advance Kandimiri, is also a service provider practicing CA.

“I started being a mechanization service provider in 2022 and adopted CA using mechanization,” said Kandimiri, who bought a tractor, a sheller, and a two-row planter.

“Conservation agriculture is more profitable than conventional farming that I was doing before I learned about CA,” said Kandimiri.

Data from CIMMYT's research indicates that farmers adopting CA practices can earn extra income of approximately USD 368 per hectare as a result of getting higher yields and reduced input costs.

Conservation Agriculture in the Region

Farmers across Southern Africa have found success after adopting CA practices with remarkable results.

In 2011, during a visit to Monze in Zambia's Southern Province, Gertrude Banda observed the significant benefits of CA firsthand. Farmers practicing CA for over seven years demonstrated how planting crops without tillage using an animal traction ripper led to reduced labour in land preparation and improved crop yields.

Banda says she was motivated by this experience to adopt CA on her own 9-hectare farm, where she grows cowpeas, groundnuts, and soybeans. She practices crop rotation, alternating maize with various legumes to enhance soil fertility and improve crop yields. Additionally, she uses groundnut and cowpea residues for livestock feed. She earned about USD 5,000 from selling her soya crop.

“Today, my entire farm follows CA principles,” Banda said. “All my crops are planted in rip lines, and I rotate maize with various legumes to maintain soil health.”

Over 65,000 farmers in Malawi and 50,000 in Zambia have adopted CA, according to CIMMYT, whose research shows that farmer education, training, and technical guidance are vital for farmers to make the shift.

However, widespread adoption of conservation agriculture has remained low despite its acknowledged advantages. Smallholder farmers face challenges in accessing inputs and equipment, said Hambulo Ngoma, an agricultural economist at CIMMYT.

Besides, farmers have limited knowledge of effective weed control and struggle with short-term yield uncertainties, which can discourage consistent practice, Ngoma said.

“While CA has proven its worth, adoption rates are still relatively low across Southern Africa," Ngoma said, adding, “Many farmers lack the resources to invest in the tools and training required for effective implementation."

Fruitful Partnerships to Promote Conservation Agriculture

Blessing Mhlanga, a cropping systems agronomist with CIMMYT’s Sustainable Agrifood Systems program, said the success of CA goes beyond technology and techniques but is hinged on education and including CA principles in national policies. In Zambia, for instance, CIMMYT, in partnership with the Food and Agriculture Organization (FAO), helped design a mechanization strategy that has paved the way for mechanized CA to be incorporated into government-led agricultural programs.

"Technologies like intensification with Gliricidia, a fast-growing nitrogen fixing tree, strip cropping, and permanently raised beds are now part of Zambia’s national agriculture agenda," explained Mhlanga, who noted that the adoption of CA by smallholder farmers can be transformative, particularly in regions reliant on rainfed cropping.

Mhlanga said with more than 250 million hectares of land currently under CA globally and adoption rates of the CA practices increasing by 10 million hectares annually, the future of CA is promising. However, much work remains to be done in providing smallholder farmers like Mudavanhu with the right tools and knowledge to adopt conservation agriculture fully.