摘要： 采用五元二次正交回归旋转设计试验，对黄土高原旱地小麦进行了多因素多指标的定量化综合研究。以二年田间试验的数据结果为依据，应用微机建立数学模型，解析各因素作用的量化强度，并选出生产上成套的高产组合方案。研究表明，在旱地小麦生产中，不仅要重视氮磷肥和有机肥的配合，还应讲究其量比的协调。正常年份下氮肥增产的潜力较大，应稳住磷肥增施氮肥；干旱年份氮肥用量过高明显造成减产，应稳住氮肥增施磷肥。以播期播量调节群体，以有机无机互调肥效，提高水份利用率是当前旱地小麦生产的可行途径。

关键词: 旱地小麦, 组合设计, 数学模型

Abstract: A Multi-Quadric orthogonal rotational regression design is used in the quantitative synthetic multi-factor and multi index study of dryland wheat production in Loess Plateau.Based on the data of field experiments in two years,mathematical models are developed by using a mini-computer.The quantitative intensities of each factor with respect to its multi-objective functional indices are expiated by mathematical analysis and the best combination of whole set measures for high yeilding is selected by simulation.Experiment result proves that not only the mixed application of nitrogen,phosphorous and farm manure(FM)is necessary,but also the optimum ratio of these nutients is important to fulfill the desired yield in dryland wheat.Nitrogen fertilizer has greater potential for increasing yield in normal rainfall years,so while keeping the usual application of phosphates,nitrogen should be increased;while in drought years,yield will be decreased with over-application of nitrogen fertilizers.Therefore,with the normal amount of nitrogen,addtional application of phosphorous is required.It is concluded that under present conditions an feasible way for improving wheat yield in dryland is a combination of optimum population with optimum seeding date and rate,increasing the fertilizing efficiency by using inorganic fertilizers and FM,and improving water utilization.

Key words: Dryland wheat, Combination design, Mathematical model