利用持续16年的长期田间试验与气象观测资料，对下辽河平原不同降水年景作物对施肥的增产反应及水分对肥料增产的促进作用、不同水肥条件下玉米对养分的吸收与分配以及玉米农田土壤养分收支进行了研究；并估算了该地区水肥交互作用对作物增产的贡献；同时，利用沈阳地区近50年气象与玉米单产历史资料，建立趋势—随机预测模型，以预测该地区不同气候年景玉米产量。研究结果表明，该地区玉米蒸散耗水与其生育期内降水之间关系密切，且不同的施肥处理对玉米消耗水分量影响不大。过少或过多的降水均会降低玉米产量；在高肥力水平下平水年（降水400～550mm）玉米产量最高，水肥交互作用对作物增产的贡献亦达最大，可占总增产量的44.9%。玉米体内养分浓度及养分在籽实与秸秆中的分配比例明显受施肥、降水及作物生长状况的影响。在平水年条件下，养分在籽实内累积的比例最高；同时，作物生长状况愈好，形成单位籽实产量所需养分量有减少的趋势，有利于提高作物体内养分的转化利用效率。施肥条件差异可使玉米收获移出农田的养分量相差2～3倍。水分条件对养分移出量的作用不如施肥明显；N肥施用加剧了土壤P的赤字，而N、P肥施用可加剧土壤K收支赤字；水分条件的改善也会明显加快养分收支赤字过程。通过对沈阳地区玉米单产与气象因子的分析，建立趋势—随机预测模型，发现热量因素对玉米产量形成有着重要作用；而养分均衡供给可提高玉米对不利气象条件的耐抗能力，具有稳产作用；同时，利用长期定位试验结果对模型加以验证，发现模型预测结果与长期定位试验结果非常吻合。

Based on a consecutive sixteen years field trial and meteorological observation data, the response of increasing crop yields to fertilization in different precipitation years was studied. The effects of fertilization and precipitation on the nutrient uptake and distribution of maize and on the nutrient budget of N, P, and K in farmland soil were also analyzed. And the effects of water-nutrient interaction on maize yields in low reach of Liaohe River Plain were estimated. At the same time, for maize yield forecasting with different meteorological conditions, the trend-state mathematical model was set up by 50 years yield of maize and meteorological observation data. The results show that, the evapotranspiration was significantly correlated with the precipitation in the growth stage of maize. Under different conditions of fertilization, the water consumption of maize was similar. At the same time, the crop growth was directly influenced by the water supply, and the yield decreased markedly in waterlogging or drought years. Under high level fertilization treatments and fitting water supply (normal rainfall), the increase of crop yields was the highest; the effect of water-nutrient interaction on maize yields was the most significant, and it accounted for 44.9% of the total increased crop yields. The nutrient concentration and the ratio of nutrients in grain vs. in stalk of maize were significantly influenced by fertilization, precipitation and crop growth status. In normal precipitation years, the ratio of nutrients accumulated in grain was the highest; the better the maize growth and the less the consumption of nutrients in producing each unit of grain products are beneficial to increase the utilization efficiency of nutrients. The quantity of maize nutrients transferred from the system increased by a factor 2～3 in different fertilization conditions and it was more significantly influenced by fertilization than precipitation. Application of nitrogen fertilizer accelerated a large deficit of soil phosphorus, and the use of nitrogen and phosphorus accelerated the deficit of potassium. The process of deficit of soil nutrient was shortened with improving of precipitation condition. The trend-state mathematical model was established by analyzing per unit area yield of maize and meteorological data over the period 1995～2004. The result indicated that the heat resource was very important to maize yield, and the stress tolerance of maize was improved with balanced nutrients supplied. Finally, the model was proved by the results of long-term location trial; it was shown that the forecasting meteorological yields were highly coincident with the real results. Keywords：Low reach of Liaohe River Plain; Maize yield; Effects of water and nutrient interaction; Budget; Yield forecasting.