红壤性水稻土施肥的产量效应及与气候、地力的关系

以23a红壤性水稻土化肥定位试验为对象，探讨了不同施肥措施下水稻产量变化及其与气候、地力的关系。结果表明：不同施肥措施的产量效应均显著受气候的年成变化及其交互作用的影响，气候的季相变化因不同施肥措施而异，对CK、NK、NPKM处理影响不大，而对N、NP、NPK处理有强烈的影响；红壤性水稻土基础地力贡献率较稳定，为46．3％，72．0％。随着施肥结构完善，对地力贡献的依赖性表现出NPKM〈NPK〈NK、NP〈N的趋势；各施肥管理水稻平均增产效果表现为NPKM〉NPK〉NK〉NP〉N。连续施用氮（N）肥，增产效果达持续显著水平的年限为17a，钾（K）肥的为98，而磷（P）肥不明显。N肥单施或与P肥、K肥配施，生产稳定性显著下降，且随时间的延长，增产效率均呈线性下降，其下降速率表现出NP〉N〉NK的趋势，至18～218后，产量水平相当或者低于无肥区（CK）。N肥与PK肥配施，可显著提高水稻生产的稳定性和产量，再配施有机肥，水稻增产效果更为明显。

CROP YIELD RESPONSE TO FERTILIZATION AND ITS RELATIONS WITH CLIMATE AND SOIL FERTILITY IN RED PADDY SOIL

Based on a 23-year stationary field experiment on fertilization in red paddy soil,crop yield response to fertilization and its relationship with climate and soil fertility was probed.The experiment was designed to have six treatments,i.e.CK,N,NP,NK,NPK,and NKPM.Results show that changes in annual climate and its interaction caused significant variability of crop yield in all the six treatments,while the impact of changes in seasonal climate on crop yield varied between treatments,little in Treatments CK,NK and NPKM,but strong in Treatments N,NP and NPK.Soil fertility contributed stably to crop yield,at a rate ranging from 46.3% to 72.0%.With improvement of the fertilization recommendation,the six treatments fell into an increasing order of NPKMNPK>NK>NP>N in terms of crop response.Significant crop response to N fertilization lasted 17 years,and to K fertilization 9 years,but no significant crop response to P fertilization was observed.Stability of the production decreased significantly in Treatments N,NP and NK.With the time going on the decline appeared in a linear curve and the three treatments were in the sequence of NP>N>NK in terms of decreasing rate.During the period from the 18th to 21st years,their yields were close to or even lower than that Treatment CK.The production of rice,in both stability and yield,was raised significantly in Treatment NPK,where the crop response was more significant when organic manure was used to replace part of the N fertilizer.