| Intro |
The Hai Basin in China exemplifies problems that are observed in many arid environments: excessivewater consumption, depletion of aquifers, and damage to eco-systems. Progressively since the 1970swater resources in Hai Basin have been over-exploited, primarily for irrigation, while the water require-ments of other sectors have increased. Water tables are falling and outflows to the sea are sporadic andheavily polluted. Current consumption of water in the basin is estimated to exceed the renewable sup-ply from rainfall by 6.25 × 109m3yr−1. Traditional approaches—improving irrigation efficiency throughstructural works and on-farm technologies such as drip and sprinkler—have failed to restore a balance.Researchers have investigated various on-farm techniques to reduce consumption, including mulching,zero tillage, deficit irrigation, revised cropping patterns, and improved cultivars. We project the results ofsuch experiments for winter wheat (Triticum aestivum L.), maize (Zea mays L.), and cotton (Gossypium spp.)to basin scale to assess their potential in restoring sustainable water consumption. Widespread adoptionof mulching, which is the most promising option for farmers, would reduce the over-consumption by25% (1.6 × 109m3yr−1). If water quotas are introduced, forcing a reduction in consumption, current pro-duction could be maintained while saving 4.1 × 109m3yr−1. Ending the remaining over-consumption of2.15 × 109m3yr−1would require reducing grain production by 4–7.8 Mt yr−1. |
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