紫色丘陵区保护性耕作条件下水稻优化施肥模式研究

应用二次正交回归旋转组合设计方法,研究了紫色丘陵区保护性耕作下麦秆还田量、施氮量(N)、施磷量(P2O5)、施钾量(K2O)和氮肥施用次数的主效应和交互效应与水稻产量的关系。结果表明:保护性耕作下水稻最高单产8722.5kg/hm2,偏离平均单产1101kg/hm2,最低单产7222.5kg/hm2,偏离平均单产1344kg/hm2,试验田水稻施肥技术代表了本区域水稻生产实际情况,能提炼出符合本区域大田生产的高产、高效科学施肥方法。根据回归模型得出3125种配方施肥方案,从中优化筛选出5套方案,而最优化方案为:2hm2麦田的小麦秸秆还田于1hm2稻田中,每公顷施纯氮270kg、磷90kg、钾45kg,施氮量按底肥、分蘖肥、拔节肥、穗肥、粒肥5次各60%、10%、10%、10%、10%施用,钾肥底肥、穗肥各50%,可获得单产约9450kg/hm2,每公顷收益可达12600元左右,收益比为6.42。农田保护性耕作措施是非常切合时宜的,是培肥地力,改良土壤,优化农田生产小环境,保证耕地可持续生产的得力措施。

Study on Optimum Fertilized Mathematical Model of Rice under Conservational Tillage on Purple Slope Land

The five factors quadratic regression orthogonal rotational combination design was adopted in this experiment to study the relations among the yield and the main effects and interaction of five synthetic measures of different amount of straw mulch, fertilizer N and its times,P2O5 and K2O in the conservational tillage practices of rice. The result showed that the highest yield was 8722.5 kg/hm2, which was higher than average yield 1101 kg /hm2, and the lowest yield was 7222.5 kg/hm2, which was lower than average yield 1344 kg/hm2. The fertilization technique of experiment represented the local rice management practices and scientific fertilization methods according with field production could be obtained from this experiment. 3125 fertilized mathematical models were achieved according to regression analysis and then 5 optimum fertilized mathematical models were chosen. The best amount of fertilizer that obtained yield 9450 kg/hm2 , income 12600 yuan/hm2 and income ratio 6.42 is: straw mulch magnitude of 1hm2 is the residues of 2hm2, pure nitrogenous fertilizer is 270 kg/hm2,which were divided into 5 phases as follows: bottom, tiller, elongation, fringe and grain, and at the ratio of 60%?10%?10%?10%?10%, respectively. Pure phosphate fertilizer is 90 kg/hm2, pure K-fertilizer is 45 kg/hm2. And the mathematical model between the yield and five factors have been set up.Adoption of no-tillage, straw mulch and fertilization significantly influenced rice yield, suggesting it was a valuable conservational practice for rice production on paddy soils.