黄土旱塬长期施肥条件下小麦钾素营养和肥料利用率的研究

Study of Potassium Nutrition of Wheat and Fertilizer Use Efficiency under Long-term Fertilization Conditions in Dryland of Loess Region

[目的]为了给黄土旱地经济合理施肥、粮食增产提供科学依据。[方法]在长期定位试验的基础上，研究了不同施肥对小麦产量、各生育期钾素营养和肥料利用率的影响。[结果]不同施肥小麦增产效果差异显著。单施氮肥小麦增产75．3％，单施磷肥小麦产量则降低24．7％，NM、PM、NPM配施小麦增产75．9％-92．9％；小麦钾素的吸收主要集中在生长发育前期，孕穗期以后因泌钾现象多表现为负吸收，施用有机肥，特别是无机肥与有机肥配施，促进小麦吸钾作用明显，小麦植株各器官含钾量明显提高；单施N肥、NP配施小麦钾素的吸收量、吸收速率较高，单施有机肥及有机无机肥配合施用小麦钾素吸收量和吸收速率比对照也有明显提高；单施N肥小麦氮肥利用率较高为76.73％，单施P肥小麦磷肥利用率较低仅为14.20％，NP配施与单施P肥相比，吸磷量、吸钾量分别增加112.53％和79．36％。施用有机肥可以显著提高作物氮、磷、钾吸收量，但肥料利用率却不高。[结论]施用有机肥以及有机无机肥配合施用，可以明显促进小麦对氮、磷、钾养分的吸收，提高小麦产量。

[ Objective] The purpose of the experiment was to provide scientific basis for rational fertilization and grain yield increase in dryland of Region. [Method] Based on the long-term located experiment, the effects of different fertilization on wheat yield, potassium nutrition in each growth stage and fertilizer use efficiency were studied. [ Resnlt] N application could increase wheat yield by 75.3% while P application conld decrease wheat yield by 24.7%.The combination of NM, PM, NPM application conld increase the wheat yield by 75.9% -92.9%. The potassium uptake of wheat mainly concentratod on the earlier stage, after the booting stage wheat potassium uptake mainly manifestod minus, organic fertilizer application, especially, the combination of organic fertilizer and mineral fertilizer conld obviously increase the potassium uptake of wheat. N application and the combination of NP could obviously increase potassium uptake and uptake rate of wheat. Compared with CK, wheat potassium uptake and uptake rate increased obviously with organic fertilizer application. The fertilizer use efficieney（FUE） was high when only N fertilizer was applied,which was 76.73%.While the FUE was only 14.20% when only P fertilizer was applied. The combination of N and P conld increase the absorbed amounts of N, P and K significantly,and organic fertilizer application conld also increase the absorbed amounts of N, P and K significantly while the FUE was low. [ Conclusion ] Applying manure （or manure and chemical mixed） not only could promote the absorption of N, P and K in wheat, but also conld increase wheat yield significantly.