Kenyan farmers embrace zero-tillage system to improve yields

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

The no-tillage system entails planting crops into soil that has remained unploughed after the harvest of the previous crop. Such cultivation has proven to have the potential, if carried out in conjunction with other appropriate farming practices, to improve food production, cut down labour cost in the farm by up to 20 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 habitat for organisms, including billions of beneficial microbes, nitrogen-fixing fungi, nutrients and earthworms whose digestive tracts transform the fine grains of sterile rock and plant waste into fertile soil.

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

With scientists insisting that the topsoil cannot be made overnight since it is regenerated 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.

“When a farmer tills, it means they are removing weeds, mixing in soil amendments like fertilisers, and shaping the soil into rows for crop plants and furrows for irrigation,” says Dr Kaheria Muriuki, a scientist from the Tegemeo Institute of Agriculture who is actively involved in pushing for no-tillage farming. “This results in adverse effects like soil compaction and death or disruption of soil microbes and other organisms, while washing or blowing away topsoil through erosion. No-till farming avoids these effects,” he says.

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 50 per cent.

A major 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.

“It is impractical for farmers to weed manually on 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.”

Business Daily Africa

Poor rains dash farmers' hopes in Zimbabwe

Garai Hokonya, 53, a smallholder farmer in Chivhu district, about 120km southwest of Zimbabwe's capital, Harare, has resigned himself to the unpalatable truth that the 12 hectares of maize he planted by hand are being devastated by an unseasonal and prolonged dry spell.

"I have written off the crop and am driving the cattle and goats to graze in the fields," Hokonya said. "This is painful, because my family used zero tillage [no ploughing] to prepare part of the land due to a shortage of draught-power," he said.

A decade of food insecurity - which reached its zenith in the first quarter of 2009 when nearly 7 million people, or well over half the population, needed emergency food assistance - has taken a heavy toll on livestock. Working animals were sacrificed for food in the lean times, decimating the draught-power that small-scale farmers need to plough their fields.

In response to the shortage of animals, "and on the advice of agricultural extension workers who told us that [manual planting] was going to boost our yields", small-scale farmers dug shallow holes and planted seeds manually as a substitute for ploughing. This method was seen as ideal, as fields that have lain fallow retain nutrients and so do not require large amounts of fertilizer.

Hokonya was filled with optimism. "When we started planting, the weather was good because the rains were coming steadily [in October 2009] and there was no reason to think the situation could turn as bad as it has done." But by late December he and the neighbouring farmers were anxiously scanning the blue skies for clouds, and hope turned sour.

Zimbabwe's Meteorological Services Department has forecast the chance of good rains in the coming weeks, but Hokonya is sceptical about replanting because "these forecasts are mostly wrong, and it is now too late to think about planting a new crop."

However, even before the adverse weather, relief agencies were forecasting that about 2.2 million Zimbabweans would require food aid between January and March 2011.

The latest weather hazards assessment for Africa by USAID/Famine Early Warning Systems Network (FEWS NET) indicated that Zimbabwe was among several other southern African countries experiencing poor rainfall.

"Since December, below-average precipitation and above-average temperatures continue to help strengthen seasonal moisture deficits across central Mozambique, southern Malawi, southern Madagascar and southern Zimbabwe," FEWS NET said in its assessment.

Renson Gasela, a farming specialist and the former agriculture secretary of the Movement for Democratic Change (MDC), said: "The crop situation across the country is very bad and food security is under great threat." The provinces of Manicaland, Masvingo, Matabeleland South and Midlands are also being affected by adverse weather patterns.

"We had hoped that food imports this year would be minimal, but the weather has dealt the country a big blow and yields are going to be worse than the last main farming season," Gasela predicted. "We would say we have lost about half of what we could have harvested, even though there is need to wait a little longer to get a fuller picture of the damage done."

The Crop and Food Assessment Mission of the UN Food and Agriculture Organization and UN World Food Programme projected a cereal harvest of 1.3 million tons in 2009, compared to 690,000 tons in 2008.

It was too late to replant in most parts of the country, "and even in areas where it is possible, there is no guarantee that the rains will last for long," Gasela said.

Denford Chimbwanda, president of the Grain and Cereal Producers Association (GCPA) sad, "We are heading for disaster if we don't start receiving rains within a week. It is very unfortunate, because most farmers had done their best to prepare their farms and plots."

He said most farmers got fertilizers too late, at a stage when they could not apply it because of low soil moisture. "Because of the little rain that has fallen so far, farmers cannot top-dress their crops, yet this is vital."

Innocent Makwiramiti, a Harare-based economist, said the spectre of another poor harvest was already being seen in the maize price. "Traders have already started speculating and are responding to the looming drought by increasing the price of maize [the staple food]."

He said, "A 50kg bag ... that used to cost around US$9 is now selling for US$15; this could also push up the price of mealie-meal [maize-meal] in shops, regardless of whether it is locally produced or imported." 

IRIN

Agricultural practices causing global loss of top soil

While many worry about the potential consequences of atmospheric warming, a few experts are trying to call attention to another global crisis quietly taking place under our feet.

"The estimate is that we are now losing about 1 percent of our topsoil every year to erosion, most of this caused by agriculture. We're losing more and more of it every day," said David Montgomery, a geologist at the University of Washington.

On average, the planet is covered with little more than 3 feet of topsoil -- the shallow skin of nutrient-rich matter that sustains most of our food and appears to play a critical role in supporting life on Earth.

"It's just crazy," fumed John Aeschliman, a fifth-generation farmer who grows wheat and other grains. "We're tearing up the soil and watching tons of it wash away every year," he said. Aeschliman is one of a growing number of farmers trying to persuade others to adopt "no-till" methods, which involve not tilling the land between plantings, leaving crop stubble to reduce erosion and planting new seeds between the stubble rows.

Montgomery has written a popular book, "Dirt," to call public attention to what he believes is a neglected environmental catastrophe. A geomorphologist who studies how landscapes form, Montgomery describes modern agricultural practices as "soil mining" to emphasize that we are rapidly outstripping the Earth's natural rate of restoring topsoil.

"Globally, it's clear we are eroding soils at a rate much faster than they can form," said John Reganold, a soils scientist at Washington State University. "It's hard to get people to pay much attention to this because, frankly, most of us take soil for granted."

The National Academy of Sciences has determined that cropland in the U.S. is being eroded at least 10 times faster than the time it takes for lost soil to be replaced.

The United Nations has warned of worldwide soil degradation -- especially in sub-Saharan Africa, where soil loss has contributed to the rapidly increasing number of malnourished people.

Healthy topsoil is a biological matrix, a housing complex for an incredibly diverse community of organisms -- billions of beneficial microbes per handful, 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.

As such, true living topsoil cannot be made overnight, Montgomery emphasized. Topsoil grows back at a rate of an inch or two over hundreds of years. Very slowly.

Ron Myhrum, state soil scientist with the U.S. Department of Agriculture's office in Spokane, agreed that global soil loss is a huge problem. But Myhrum said erosion rates in the Northwest region have improved recently because of better conservation farming practices, including federal payments to farmers to leave some natural ground cover in highly erodible areas.

"We don't have the kind of dust storms here we used to have," Myhrum said. "What's more alarming to me than erosion is conversion of farmland to urban use."

That is indeed another way to lose soil -- paving it over. Judy Herring, manager of King County's farmland preservation program, said the county has lost 60 percent of its farmland since the 1960s. In 1979, Herring said, voters approved a bond program that buys back farmland to protect it from development (and has done this for 13,200 acres so far).

But while some land is lost to development, pollution or changing weather patterns, Montgomery, Reganold and others say global soil loss is a crisis mostly rooted in agriculture.

"Erosion rates have improved here, but that doesn't mean they're good," Reganold said. Topsoil clearly is still being stripped off faster than it can be regenerated, he said.

Aeschliman, the Palouse farmer, a stocky and energetic man who doesn't seem to notice that he's in his 60s, stood on a dirt road looking at the difference between his land and that of a neighbor. Because most neighbors are relatives, he did not provide any names here.

"Just look at that!" he bellowed, pointing to a series of water-carved cracks and gouges running down a recently tilled field of wheat. Every year, he said, these fields are tilled and the rains come, washing the soil down into the road so deep the county routinely has to dig it out. The rest of the soil runs off ... eventually to the Pacific.

"Here, look at this stuff," Aeschliman said as he held up a handful of the fine brown silt that had eroded off his neighbor's hillside. "Now, look over here."

He walked across the road to his no-till wheat field. Unlike the rolling hills of loose dirt on the tilled field, Aeschliman's field looks more like a shag rug, with its rows of dead wheat stubble. He reached down into the dirt and pulled out a coarsely textured, much darker clump of dirt, roots and debris.

"This soil is full of worms, bacteria and all sorts of life," Aeschliman said. "And it stays put. That stuff over there (waving his hand back behind him) is just powder, brown dust. It's dead. There's no worms, no life in it."

Thirty years ago, Aeschliman was one of the first in the area to grow his grains using no-till farming methods. He's an ardent no-till proselytizer today, but he didn't abandon tilling the fields based on some organic epiphany or desire to save the world.

"I just got tired of all the mud," Aeschliman said. The family home, built in the 1880s, sits at the base of a long drainage off the rolling wheat fields. Every spring, with the tilling and the rain, his home would be a foot deep in muddy runoff.

No-till farming could do a lot to reduce topsoil erosion, Reganold said, but it's not without its downsides. Switching to no-till farming requires heavy upfront investment and learning new techniques, he said, and also tends to depend more on herbicides because the weeds are no longer controllable by plowing them into the soil.

Organic farming methods also can reduce soil loss, Reganold said. He cited his own research, which has shown a marked increase in soil health, water retention and regrowth when organic methods are used rather than the traditional methods.

A regional association of farmers and other proponents of no-till agriculture, also known as direct-seed farming, is holding its annual meeting in next week. Aeschliman is one of the founders of the organization, the Pacific Northwest Direct Seed Association, and is happy to see that no-till farming is growing in popularity.

"It's both good for the soil and good for your pocketbook," he said.

Seattle Post Intelligence

Zero tillage reduces water demand in rice, wheat farming

Zero tillage has reduced the demand for water in rice and wheat farming on almost a million hectares of land in Bangladesh, India and Pakistan.

Scientists from the International Maize and Wheat Improvement Center (CIMMYT) and the Rice Wheat Consortium for the Indo-Gangetic Plains — a network of scientists and nongovernmental organisations — carried out the investigation.

Their work is highlighted in the World Bank's 'World Development Report 2008: Agriculture for Development', published on 19 October.

This is the first time in 25 years that agriculture's role in development has been the focus in the World Bank's annual development report. It calls for increased funding for agricultural research and for making agriculture central to the development agenda.

Rice and wheat are important for southern Asia's food security, but yields have recently been stagnating and soil quality deteriorating.

A 'rice–wheat' farming system has a summer 'wet' crop of rice — during the monsoon season — and a winter 'dry' crop of wheat.

The scientists introduced zero tillage — also known as conservation tillage — to farmers in the region. Zero-tillage involves planting seeds into soil that hasn't been tilled after the harvest of the previous crop. The wheat seeds germinate in residual water left by the rice crop, saving up to a million litres of water per hectare.

Atique Rehman, an agricultural student at the University of Agriculture, Faisalabad, Pakistan, said, "In the conventional method, soil needs to be soaked, which requires much more irrigation water. In zero tillage, soaking irrigation is skipped as sufficient moisture is available after the harvesting of the rice crop."

With zero-tillage, farmers can produce higher yields and reduce production costs by up to ten per cent. They also save on diesel fuel for tractors, and the fertility and structure of the soil improves.

The report also highlights researchers' efforts to produce drought-tolerant maize for Africa. Creating new varieties can take decades of research, but these are now reaching farmers and yields are stabilising.

The report warns that the production of improved crops is a lengthy process and cannot be undertaken without proper investment.

SciDev.Net

FAO project promotes Brazilian technology for low-tillage agriculture in Africa

A new FAO project seeks to boost agricultural production in Kenya and Tanzania by encouraging a shift to conservation agriculture (CA) techniques, which optimizes the use of farm labour and could also help reduce widespread land degradation. CA techniques include reduced or no-tillage (NT) of the soil, and the use of permanent soil cover.

The project will forge links between farming communities in the two countries and Brazilian firms specialized in production of equipment used in CA. Under the three-year, German-funded project, up to 4,000 farmers are to be trained in CA practices through participatory field schools.

Conservation agriculture is based on three principles: (1) minimal soil disturbance, to preserve soil organic matter (2) permanent soil cover (cover crops, residues and mulches) to protect the soil and suppress weeds without the need for chemical herbicides and (3) diversified crop rotations and associations to promote soil micro-organisms and disrupt plant pests and diseases.

Since dedicated CA implements - such as knife-rollers and direct seeders - are not widely available, the project will take Kenyans and Tanzanians to Brazil to study CA technologies and will design strategies for developing a sustainable equipment supply chain in the sub region. Lessons learned will be "up-scaled" and disseminated throughout Africa.

The FAO says conservation agriculture offers Kenyan and Tanzanian farmers a pathway to sustainable agriculture and rural development, which hinges on sustainable land management and better use of available farm labour. In Tanzania, where the economy is based mainly on small-scale farming and livestock, an estimated 44 percent of the rural population lives below the poverty line. In neighbouring Kenya, the incidence of rural poverty is around 50 percent, despite strong recent growth in the farm sector.

In both countries, land degradation is a major constraint on the productivity of labour and other external inputs. The reduction in farm labour availability due to migration, HIV/AIDS and other diseases has forced farmers to abandon traditional methods of land preparation and other farm operations. Many now plant seed directly into unprepared land immediately after the onset of rain.

"While farmers and extensionists often regard such practices as a poor way of farming, planting without ploughing uses less human labour and animal power," says Josef Kienzle of FAO. "Far from being a mere 'coping mechanism', no-tillage cultivation has the potential - if carried out in conjunction with other appropriate agronomic practices - to become an important part of strategies to improve food production and stabilize threatened rural livelihoods."

The benefits of no-tillage on small farms are well known in Brazil, which has pioneered conservation agriculture in tropical and subtropical farming systems. The first prototype NT seeder and a prototype knife-roller for residue management were designed in 1985. In 1992 a provincial government launched a large-scale evaluation of CA systems and ordered 50 seeders and other equipment from a local manufacturer.

Direct seeding was soon recognized as an excellent means of natural resource conservation, which attracted financial support from the federal government for a programme that encouraged farmers to adopt the innovations.

Biopact