Spectacular rice yields
Once in a while, the world gets rocked by reports about spectacularly high crop yields. Usually, these high yields are obtained by farmers or other individuals and the results are pitched by the media as “baffling conventional scientists.” For example, on 21 November 2012, the Oryza Newsletter revealed that “Professor Fida M. Abbasi of Pakistan’s Hazara University-Mansehra surprised everyone by revealing the results of his 12-year-old rice research, which resulted in rice plants growing 6-feet tall with potential yield of a record 15 tons per hectare, almost four times the current world average of around 4 tons per hectare.” It further stated that Professor Abbasi “… started the research in 2000 with no funding and little encouragement.” The same discovery was revealed one year earlier by the Express Tribune (27 November 2011): “A Hazara-based agriculture scientist claims to have developed the world’s highest rice yield variety; “Dr. Fida Muhammad Abbasi, a professor of genetics at Hazara University, told The Express Tribune on Thursday that the existing varieties do not produce more than 5 tons per hectare; however, the new variety would yield 12 tons per hectare.” In one year, the yield potential of this new variety had jumped from 12 to 15 tons per hectare, about 3 times that of existing varieties. This year, on 16 February, The Guardian revealed that “Sumant Kumar, a shy young farmer in Nalanda District of India's poorest state, Bihar, had—using only farmyard manure and without any herbicides—grown an astonishing 22.4 tons of rice on 1 hectare of land” and “it beat not just the 19.4 tons achieved by the ‘father of rice,’ the Chinese agricultural scientist Yuan Longping, but the World Bank-funded scientists at the International Rice Research Institute in the Philippines, and anything achieved by the biggest European and American seed and GM companies.” It didn’t take long for Yuan Longping (actually, the “father of hybrid rice”) to respond (The Global Times, 22 February 2013): “Chinese revered agricultural scientist Yuan Longping Wednesday slammed a British news report about an Indian farmer who claimed his rice crop yielded an astonishing 22.4 tons per hectare” and “Yuan questioned the verification of the record and the reasons given for achieving such a huge yield.”
So, what are we to make of such reports on high yield? My own experience so far has taught me that “if things are too good to be true, they usually aren’t.” Let’s look at the official statistics on rice production in Bihar, India: between 2002 and 2011, yields varied from 0.79 to 1.60 tons per hectare. The period 2011-12 showed a good average yield of 2.1 tons per hectare, which was twice that of 2010-11 but not “miraculously” high compared to the last 10 years. Good yields under rainfed conditions in Bihar are on the order of 3.5–4.5 tons per hectare. So, the reported 22.4 tons per hectare certainly stands out as a remarkable feat! According to The Guardian, this high yield was obtained without any fertilizers or herbicides, but by reducing the amount of seed used, planting young seedlings as single plants per hill, reducing water inputs, doing manual weeding, and using farmyard manure. These technologies have basically been available for hundreds, if not thousands, of years, so I can’t help wondering why millions of farmers all over the world for all these thousands of years have not been able to produce 22 tons before? Why did we have to wait for the advent of the Green Revolution before we were able to significantly increase yields on a global scale?
I think we shouldn’t be swept away by promises of super-high yields but look at what can realistically be accomplished to increase yields. The practices applied by farmer Kumar in Bihar are components of the System of Rice Intensification (SRI). A lot has been written in the scientific (and not so scientific) literature about SRI and its promises of (super) high yields. SRI is an agroecological methodology to increase the productivity of irrigated rice, which has spilled over into rainfed rice and nonrice crops. Though SRI started as a set of three essential “principles” (young seedlings, single spacing, and reduced water use), it has evolved into a participatory learning alliance that aims to offer farmers a suite of management practices to choose from and adapt according to local conditions. Its implementation in various parts of the world has incorporated various best management practices, such as the leaf color chart to guide the application of fertilizers. Similar successes are reported when using a system called Rice Check by which best management practices are combined to produce “the desired crop” in the field. Using such an approach, average yields of irrigated rice in Uruguay and southern Brazil have increased from some 5.5 tons per hectare in 2002 to 7–8 tons per hectare in recent years. Though not as spectacular as 22.4 tons per hectare, this increase is still quite an accomplishment! The successes of SRI, Rice Check, and similar approaches lie in their participatory, experiential learning approaches to find and apply the best technological means to achieve high yields. It is the task of science to advance the frontier of best technological means and to find the best ways of combining them in the field so farmers can reap the benefits. And, it is to this task that the more than 900 partners of the Global Rice Science Partnership (GRiSP) have dedicated themselves.
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