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对三峡地区玉米降水生产潜力及适宜开发度进行研究。结果表明:在玉米全生育期,自然降水总量的41.9%用于农田蒸散。坡地与平地相比,坡地地表径流量占降水总量的28.3%,平地地表径流量占降水总量的12.3%;耗水系数平均为0.136mm/(kg·hm2),比平地低0.007mm/(kg·hm2)。影响玉米降水生产潜力的主要障碍因子是施肥水平、降水量和土壤侵蚀。随着施肥水平的提高,降水生产潜力增大,且施肥水平对坡地降水生产潜力的影响比平地更加明显;水土流失增加,降水生产潜力降低,降水量对降水生产潜力的贡献值为-3.135kg/(mm·hm2),即每减少降水量1mm,坡地降水生产潜力平均下降3.135kg/hm2。在现有技术、土壤、投入水平及管理条件下,三峡地区大田玉米降水生产潜力开发程度(MKD)较低,坡地约60%～65%,平地约65%～70%。坡地玉米降水生产潜力适宜开发度(SKD)可达80%,平地可达90%。可开发程度(KKD)坡地平均为17.5%、平地平均为17.9%,平地降水生产潜力可开发程度比坡地稍大。
Study on precipitation potential productivity and suitable development degree of maize in the Three Gorges area. The results showed that 41.9% of the total precipitation was used for farmland evapotranspiration in the whole corn growing period. Compared with plain, the slope surface runoff accounted for 28.3% of the total precipitation and surface runoff accounted for 12.3% of the total precipitation. The average water consumption coefficient was 0.136mm / (kg · hm2), which was 0.007mm / (kg · hm2). The main obstacle factors affecting the potential of precipitation production in maize are fertilization level, precipitation and soil erosion. With the increase of fertilization level, the potential of precipitation production increased, and the effect of fertilization level on the potential of slope precipitation was more obvious than that of flat land. The soil erosion increased, the potential of precipitation decreased, and the contribution of precipitation to precipitation potential was -3.135kg / (mm · hm2), that is, for every 1mm reduction in precipitation, the potential for precipitation on sloping lands drops by an average of 3.135kg / hm2. Under current technologies, soil conditions, input levels and management conditions, the MKD for field corn production in the Three Gorges area is relatively low, ranging from 60% to 65% on sloping fields and about 65% to 70% on flatlands. Precipitation potential of slope maize production potential (SKD) up to 80%, up to 90% of the ground. The KKD averaged 17.5% of the slopes and the average of the flatlands was 17.9%. The production potential of flatland precipitation could be developed slightly larger than that of the slopes.