China's water challenges
IATP President Jim Harkness reflects on World Water Day and his recent visit to Beijing.
On this World Water Day, I can’t help but think of my departure from China a couple of days ago. I flew out of Beijing in the middle of a massive dust storm. Howling winds in parched Inner Mongolia picked up countless tons of fine red soil and deposited them over a large swath of Northeast Asia, Japan and Korea. As our plane bucked and lurched up into the dirty-orange gale, I tried to distract myself by reading the complimentary China Daily the flight attendant had handed me before takeoff, and found that the perennially water-short North China plain is not the only area of the country that is suffering. Southwest China is in the throes of its worst drought in over a half century, affecting over 20 million people in Yunnan, Guizhou and Guangxi provinces. Harvests will likely be only 50 percent of their 2009 levels. The poorest farmers, who live in mountainous areas and depend on rains for their crops of maize or potatoes, will be hit hardest. This year reservoirs and rivers are also drying up. That means irrigated rice, the staple of urban populations, will also suffer.
The general thrust of China’s approach to water shortages has been to increase supply. Whether the underlying ideology was socialism or capitalism, more inputs (water, pesticides and fertilizer) and greater productivity have long been seen as the solutions to China’s food security challenge. As surface water disappeared from the North China plain, subsidized tube wells sucked groundwater from deeper and deeper, draining aquifers much faster than they could possibly re-charge. And in the past decade, with the wells running dry, work began on a massive project to transfer water from the South to the North via a network of reservoirs, pipes and canals that would divert trillions of gallons of the Yangtze’s flow northward. A recent decision to halt the most disastrous part of this project was a major victory for China’s scientifically and politically savvy water activists, but a more fundamental shift toward reducing waste and increasing efficiency of water use is still a long way off.
One of the more interesting sessions at the International Conference on Sustainable Agriculture and Food we co-hosted in Beijing last week was about efforts to drastically reduce water use in paddy rice farming through adoption of the System of Rice Intensification (SRI). More a set of principles than a specific farming technique, SRI includes a focus on reduced use of inputs, wider spacing of seedlings and careful treatment of roots during transplanting. Instead of keeping the paddy flooded, SRI calls for the soil to be kept moist but aerated, in order to promote beneficial soil microorganisms. SRI has a growing host of proponents among grassroots development workers and farmers’ groups, but critics in major rice research institutions have questioned its scientific basis, and major field trials are currently underway.
One aspect of SRI that has made it difficult to assess is that it is intentionally flexible, so it can be adapted to local conditions, and the variation in local adaptations was evident in the contrasting approaches to SRI presented at our conference. Mr. Uwe Hoering, a German agronomist, described the widespread adoption of SRI in Cambodia, where it is essentially a very low-input, labor-intensive, organic farming system. Mr. Lu Shihua of the Sichuan Academy of Agricultural Sciences, one of the principal proponents of SRI in China, described a rather different system, using chemical fertilizer and substituting plastic sheeting for mulch as a weed control and moisture retention measure. This seemed much less environmentally friendly than the Cambodian version, but they shared the key element of water savings. In Sichuan, where over 100,000 hectares are now planted using SRI, two-thirds less water is used. The yields from SRI are marginally higher on average, but much higher in drought years, which are becoming increasingly common.
We will be posting Mr. Lu’s presentation, along with all of the others as well as video of the plenary sessions, in the next week or so. Stay tuned.
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