宁南山区主要粮食作物生产力和水分利用的研究

 在3个有代表性的气候年份（1981-1983年），6种地区类型，两种肥力条件下对宁夏南部山区主要粮食作物：小麦、糜子和谷子的生产力和水分利用进行了研究。结果表明：该地区当前粮食作物平均生产水平为亩产75公斤，蒸腾蒸发量（ET）280mm，水分利用率（WUE）0.27，作物对土壤储水利用程度为53.3%。提高土壤肥力可显著提高作物对土壤水分的利用效率和利用程度。根据试验资料，预测了该地区粮食作物的生产潜力，讨论了3种作物对气候、土地的适应能力及合理布局。

A STUDY ON PRODUCTIVITY AND WATER USE OF MAIN CROPS IN SOUTHERN NINGXIA HILLY AREA

In a study on the productivity and water use of wheat, proso (Panicum milliaceum) and foxtail millet (Seteria italica) (1981-1983) in 6 different landforms of 2 different fertilities in Southern Ningxia, a semi-arid and severe eroded area in loessal hilly zone. The mean cereal crop yield is 75kg/mu, the evapotranspirution (ET) 280 mm, the water use efficiency (WUE) 0.27 (kg grain yield/mm water comsumption). The water use in crop growing seasons is 53.3% of water stored in soils The cereal garin yield may reach 125kg/mu in recent yeaes and above 200kg/mu in the future as predicted based on the facts that the WUE has reached the upper limit (0.75) and water use at the maximum (70%).Climate and soil fertility are the two major factors influencing grain yield which has 83% variation between years of different climate, and 66% of different soil fertility. Improvement of soil fertility results in significant higher WUE. The regression equation between yield (Y) and ET (X) may be expressed as Y=-117.47+0.63X n=45, r=0.73 (at low soil fertility) and Y=-117.4+1.33X n=45, r=0.82 (at high soil fertility). The ET in wheat, proso and foxtail millet are 295mm, 247mm and 300mm respectively. The mean grain yield and its variation coefficients are 71kg and 59.7% for wheat; 79kg and 74.5% for proso and 74.5kg and 80.8% for foxtail millet. It is believed that the major factor responsible to the low yield is not fully use of soil moisture due to the low level of fertilizer applied, in addition to the insufficient rainfall; and the improvement of soil fertility is the principal measure for increasing WUE and the yield.