Maize, rice and wheat, the world’s major cereals, can be grown in ways that take into account sustainability for a better future.
A book published by the Food and Agriculture Organization (FAO) of the United Nations advocates “Save and Grow” technique when it comes to farming.
According to the UN food agency, environmentally-friendly farming methods can take us to a more sustainable future, keeping in mind the sustainable development agenda of ending hunger and poverty by 2030.
“We need a global transition to a more resilient and sustainable agriculture that is less dependent on agrochemicals and draws more on natural biological and ecosystem processes,” FAO’s deputy director of plant production and protection division William Murray said.
It has been estimated that by 2050, the annual global demand for maize, rice and wheat will reach almost 3.3 billion tonnes (800 million tonnes).
According to Murray, reaching the target will be more difficult than in the past owing to widespread degradation of farmlands, increasing competition for land and water, stagnation in growth of cereal yields and the impacts of climate change (higher temperatures, intense droughts and flooding).
CREDIT:FAO
The “Save and Grow” practice consists of a set of techniques that advocate natural ecosystem processes to “produce more with less”.
The technique focuses on conservation agriculture, maintaining soil health, selecting crops with higher yield potential and greater resistance to climate change, efficient water management and pest control.
One such example practised in Asia (China) is the rice-fish farming system wherein farmers rear fish in flooded paddy fields.
While on the one hand, the fish can be sold for income or eaten for nutrition, on the other hand, growing fish along with rice helps in controlling fungi and weeds that damage the crop. It thus reduces the need to depend on pesticides.
“Rice-fish is a traditional system that has been largely replaced by intensive rice mono-cropping. We are now seeing, in countries like Indonesia, a revival of aquaculture in rice fields. What “Save and Grow” can contribute is better management of fish stocking and harvesting, which has been shown to increase fish production three times over and increase rice yields by 10 per cent,” Murray told Down To Earth.
Basically, what “Save and Grow” adds to traditional systems is new technologies and practices such as higher-yielding varieties, precision irrigation, needs-based fertilizer management, bio-pesticides and direct-seeding without soil tillage, the FAO agriculture expert added.
Why does “Save and Grow” emphasise mainly on smallholder farmers growing staple cereals?
Maize, rice and wheat are the world’s most widely-cultivated crops and the foundation of world food security, with an annual production of well over 2 billion tonnes a year. The developing world’s 500 million small-scale and family farmers grow an estimated 80 per cent of the food in those countries. Small-scale farmers in Africa and Central America generally grow maize as a food crop for household consumption and for sale in urban markets. In Asia, rice is mainly a small farmer crop, with almost all of it produced on holdings ranging from 0.5 to 3 hectares.
What kinds of sustainability improvements are necessary to increase global food production by 2050?
We can restore the health of our soils by inter-cropping cereals with pulses and other legumes to reduce dependence on synthetic fertilizers. There is also a need for improved varieties that are more productive and better adapted to small-holder farming systems (as well as introduce) bio-control of pests to reduce the use of pesticides.
Does the “Save and Grow” initiative take into account the 2030 SDG target of zero hunger and end to poverty?
Achieving the Sustainable Development Goals requires a global transition to more productive, inclusive and sustainable agriculture. The “Save and Grow approach” is making a contribution to that transition by helping restore production in major grain belts where Green Revolution technologies have faltered, and raising the productivity of low-input farming systems common in Central America and much of Africa. “Save and Grow” will help governments achieve the key SDGs of eliminating poverty and hunger, raise productivity and incomes of smallholders, promote inclusive economic growth, strengthen resilience to climate change and restore terrestrial ecosystems.
Where do you think climate change will have the most pronounced effects on food yields?
Climate change impacts on agriculture will be most severe for the most vulnerable—the developing world’s small-holder farmers and the billions of low-income urban people. As maize is mainly a rain-fed crop, higher rainfall variability will increase losses in sub-Saharan Africa and Asia. Rice productivity in the tropics is forecast to decline, because many of today’s high-yielding rice varieties are intolerant to abiotic stresses that are likely to be aggravated by climate change. For wheat, the projected increased frequency of short-term high temperatures could have catastrophic effects on yields. The Indo-Gangetic Plains are currently a favourable mega-environment for wheat, but by 2050, more than half of the total area may suffer from heat stress.
Is multi-cropping more environmentally sustainable than mono-cropping?
All evidence points to the important role of crop diversification in building more productive, stable and resilient farming systems. For example, rotation of wheat with grain legumes is practised increasingly in rain-fed wheat production areas, especially in soils with low levels of nitrogen, typical of Western Asia and North Africa. The rotation of maize with other crops holds particular promise in increasing resource-use efficiency. Rice-based systems are also becoming increasingly diverse.
How has the “Save and Grow” practice helped restore production in wheat-growing regions of India?
Over the past 15 years, farmers in north-west India have been adopting key resource-conserving practices such as zero-tillage, retention of crop residues, raised bed planting of wheat, the dry-seeding of rice, and crop rotations. The adoption of zero-tillage direct-seeding in wheat production has reduced farmers’ costs per hectare by 20 per cent and increased net income by 28 per cent. Till date, zero-tillage appears to have been adopted mainly for the wheat component of the rice-wheat system.
Applied to rice, it would lead to needed reductions in the use of irrigation water. A practical measure that the book recommends is retaining the residues of the harvested rice crop so that it can serve as protective soil cover for the subsequent wheat crop. Today much of the rice straw is still simply burnt. To discourage burning-off and encourage the retention of residues, the governments of Punjab and Haryana are now upscaling a new technology, the “Happy Seeder”, which can drill wheat seed through heavy loads of rice residues.
Is there any way to reduce dependence on cereals by promoting pulses, vegetables and fruits?
Cereals will always be crucial to the human diet—they offer a concentrated source of energy, protein and other nutrients that could be easily stored. “Save and Grow” promotes the diversification of small-holder production to include pulses, fruits and leafy vegetables as well as foods with a high content and bioavailability of nutrients—meat, dairy products, poultry and fish—which address multiple nutrient deficiencies.
Rice is a water-intensive crop. According to many news sources, India’s groundwater level is depleting fast and the summer monsoon is becoming more and more erratic. Is there a way to reduce water quantity while growing rice?
Various approaches are being promoted to help farmers increase rice productivity using less water. One is alternate wetting and drying, in which the paddy is flooded and the water is allowed to dry out before re-flooding. Another is aerobic rice where seeds are sown directly into the dry soil and then irrigated. Both approaches result in water savings of 30 to 50 per cent. Another advantage is that by draining rice fields several times during the growing season, we reduce emissions of methane, an important greenhouse gas.
Keeping in mind that ecosystems and farm needs vary across the world, the “Save and Grow” concept provides scope to try out innovative farming techniques while at the same time promote sustainability.
The zero-tillage method adopted by farmers in Kazakhstan in Central Asia shows that conservation agriculture can go a long way in increasing wheat yields.
Farmers across the semi-arid steppes of northern Kazakhstan suffered huge losses after the region witnessed one of its worst droughts in 2012.
There was a dip in the country’s wheat harvest, from 23 million tonnes in 2011 to less than 10 million tonnes the following year.
“Ploughing has been the standard practice in wheat production for millennia. Only now, after some 50 years of very intensive mono-cropping in key wheat-producing regions, have the full costs become clear—depletion of soil fertility, loss of soil biodiversity, and soil’s capacity to retain moisture and nutrients,” FAO’s deputy director of plant production and protection division William Murray said.
In Kazakhstan, ploughing contributed to the loss of millions of tonnes of soil annually to wind erosion. The shift to zero or much-reduced tillage since 2000 was accomplished with strong government support with the result that wheat growing is now both more productive and sustainable.
Back in 2012, there were some lucky wheat cultivators who had adopted conservation agriculture—zero tillage, retention of crop residues on the soil surface and crop rotation and they had all the reason to smile.
While the wheat yield failed due to the severe drought, some farmers in Kostanay province achieved yields of two tonnes per hectare, almost double the national average of recent years, that very same year.
Conservation agriculture in northern Kazakhstan’s wheat belt has been driven by necessity, the FAO report says.
The country has vast land resources and is one of the world’s leading producers and exporters of wheat, but the crop relies entirely on precipitation and is vulnerable to loss of soil moisture.
As part of sustainable agriculture, wheat farmers started reducing tillage in the 1960s to cope up with high losses of soil to wind erosion. By the end of the 20th century, minimal tillage was a common practice.
Trials in the north showed that zero-tilled land produced wheat yields 25 per cent higher than ploughed land while labour costs were reduced by 40 per cent and fuel costs by 70 per cent, the report adds.
Today, Kazakhstan ranks among the world’s leading adopters of zero-tillage farming practice. The area of land that is no longer ploughed at all rose from nil in 2000 to 1.4 million hectares by 2008.
When it comes to Africa, the Save and Grow approach has contributed to a revival of the traditional practice of growing maize intercropped or rotated with legumes, such as groundnuts, soybeans and pigeon peas.
Legumes are particularly important for restoring soil health and fertility. It is estimated that globally, some 190 million hectares of grain legumes contribute to around 5 to 7 million tonnes of nitrogen to soils.
“The roots of chickpeas and pigeon peas secrete organic acids which can mobilise fixed forms of soil phosphorus and make it more readily available to cereal crops. Legumes also release into the soil hydrogen gas, which is oxidised by soil microbes and further improve soil biology,” Murray said.
According to him, farmers in Bangladesh are growing maize and Napier grass between the two main rice-growing seasons as an efficient way of producing food, earn income and provide fodder for livestock.
In the Indo-Gangetic Plains of South Asia, farmers have developed a crop rotation system that produces rice during the summer monsoon and wheat during the short winter. However, a major constraint to wheat productivity is late sowing due to late rice harvest. Precious time is also lost owing to the farmers’ practice of thoroughly ploughing the harvested rice fields.
In many areas, the wheat planting date has been brought forward by direct-seeding wherein sowing is done after the paddy harvest with no prior tillage operations. Zero-tillage contributes to higher wheat yields, in the range of 6 to 10 per cent, because it allows for timely sowing and produces a better crop stand.
The impact of Save and Grow practices and technologies is reflected in recent increases in wheat production in India. Following poor yields from 2003 to 2007 in Punjab, wheat productivity has increased steadily and average output exceeded 5 tonnes per hectare in 2012.
While Green Revolution focused on intensive production of maize, rice and wheat and improved the supply of dietary energy, it did not improve overall human nutrition. Much more attention needs to be given not only to the quantity, but also to the variety and quality of the foods produced and consumed, and this is one of the key concepts of “Save and Grow”.
Though “Save and Grow” promotes conservation, it does not entirely take us back to the old days style, a senior FAO official based in Rome said. There is a need to identify genetic species that will productively interact with ecosystems.
And here technology has a vital role to play. One such concept is laser-assisted land-levelling, which reduces water losses by as much as 40 per cent, improves the efficiency of fertilizers and boosts yields by from 5 to 10 per cent.