text size: smaller reset larger

 

 

Less water, fewer plants, more rice - the SRI revolution

New technologies for rice production are proving popular in the Middle Niger Delta (Erika Styger)
New technologies for rice production are proving popular in the Middle Niger Delta
Erika Styger

Timbuktu, an ancient trading post on the edge of the Sahara Desert, is synonymous with remoteness, of lying somewhere at the end of the road. But, for rice cultivation in Africa, this arid land in the Middle Niger Delta was the beginning: from here, rice farming spread across West Africa during the last millennium. Now, thanks to the efforts of Malian rice farmers, a new wave of rice technology has begun to ripple across the region. It has the potential to more than double yields, while raising the productivity of land, water, labour and capital.

The System of Rice Intensification (SRI), pioneered in Madagascar in the early 1980s by the French Jesuit priest, Father Henri de Laulanié, is being tested and adopted by Malian farmers, who thought that they had tried every technique available to improve their crop production. Beyond Mali, the system has already been validated in 34 other countries, including by the rice research institutes of China, India and Indonesia, which together produce 60 per cent of the world's rice. Sceptics are also taking the results seriously, with researchers at Cornell and Wageningen Universities planning a joint evaluation, together with the International Rice Research Institute (IRRI).

Fewer and further between

In SRI, rice plants are transplanted early, after just 8-12 days in an unflooded nursery, and they are planted singly, rather than in clumps. Planting is a precision task, done in a square pattern with relatively wide spacing: 25-30 cm between plants. This increases the sunlight each receives and gives roots more room to grow. Fields are ideally kept damp rather than completely flooded, creating a more aerated environment, which promotes root development and diversity of soil organisms. This also allows more weed growth, but Malian farmers have tackled this problem by using conical weeders - rotating, spiky drums which are rolled between the rows of plants, burying the weeds and aerating the soil. Because SRI seedlings are planted in a square grid, weeding along and across the rows is possible, also giving better soil aeration. This regular weeding has boosted plant vigour, eliminating competition from weeds and encouraging the infiltration of moisture and nutrients into the root zone.

The conical weeder used by farmers in Mali (Erika Styger)
The conical weeder used by farmers in Mali
Erika Styger

With SRI, fertilisation is done before planting, using compost or well-decomposed livestock manure spread on the fields prior to ploughing. During two years of field trials and demonstrations in Mali, supported by the NGO Africare, farmers saw some unwanted yellowing of the crop midway through its growth cycle, but application of a little nitrogen (in urea form) has solved the problem. The Africare team is keen to see whether building up soil fertility over several seasons, by using crop residues, for example, may remove the need for chemical fertilisers completely.

More tillers and bumper harvests

Yield in rice is closely linked to the number of tillers, the shoots that produce grain-bearing panicles, and grains per panicle. In assessing some 60 control and SRI plots, the Malian farmers found that in each case, the SRI plants had a higher number of tillers per plant (24.1 vs. 16.2) and larger panicles than the conventionally grown rice (133 grains per panicle vs. 97 grains).

These results were achieved despite some sceptical farmers attempting to make their control plots as productive as possible. Grain yield in the SRI plots averaged 9.1 tonnes per hectare, compared with 5.7 tonnes in plots where modern rice-growing methods were used, and 4.5 tonnes in nearby, traditionally-cultivated fields.

Global success

Trials in Afghanistan, supported by the Aga Khan Foundation, have seen rice yields reaching an average of 10.2 tonnes/ha in SRI plots, compared to 5.7 tonnes in control plots. In the marshy Al-Muthanna province of southern Iraq, more than 1,600 farmers have been trained in the system, and have seen yields increase by 75 per cent. In Tripura state, northeast India, where less than 1,000 farmers used SRI methods in 2005-6, there are now over 162,000 farmers using the technique, with strong backing from the state government. In Ha Tay province of Vietnam, some 3,000 hectares were under SRI in 2007. This rose to 35,000 hectares in 2008 thanks to a campaign by the Ministry of Agriculture and Rural Development with Oxfam America's support. Twenty other provinces of Vietnam introduced SRI demonstration programmes in 2008 as part of this campaign.

Trials of SRI in Afghanistan have seen yield almost double (Erika Styger)
Trials of SRI in Afghanistan have seen yield almost double
Erika Styger

The principle of planting less to get more may not just apply to rice, however. According to Cornell University professor of government and international agriculture, Norman Uphoff, these methods have worked with other crops, including wheat, sugar cane and finger millet in India. Uphoff is quick to stress that while SRI focuses on crop management rather than genetic improvement, the importance of breeding better rice varieties is not the issue. "We are not opposing genetic improvement,' he says. "All of our best SRI results come from improved rice varieties. But traditional varieties, which are tasty and have good storage and nutrition qualities, respond very well to these methods too," he explains. "What's more, consumers often prefer them, being willing to pay higher prices for them. So by making traditional varieties more productive as well as more profitable, SRI also supports rice biodiversity, and the future of rice farming everywhere."

Date published: March 2009

 

Have your say

 

The New Agriculturist is a WRENmedia production.

This website uses cookies to improve your experience. By continuing to browse the site you are agreeing to our use of cookies.
Accept
Read more