土壤供磷水平与冬小麦合理施肥

因土施肥的关键在于如何确定土壤肥力水平.根据我们按统一方案进行的多年多点田间肥料试验结果认为,土壤诸养分中速效磷含量的高低与产量有较好的相关关系:y=8.25+62.46logP r=0.8618~(**)(y为产量百分数,p为土壤速效磷测试值),所以用土壤速效磷含量做为土壤肥力指标之一在河北是可行的.根据不同土壤供磷水平配置了三个肥效方程,算出不同供磷水平土壤的经济最佳施肥量和氮磷肥施用比例,也可预测产量幅度.本试验结果从宏观上提出了河北省冬小麦施肥配方,对指导小麦科学施肥有重要意义,同时为国家安排生产和调配化肥提供了科学依据.

THE LEVEL OF AVAILABLE PHOSPHOROUS OF THE SOIL AND THE RATIONAL APPLICATION OF FERTILIZERS FOR WINTER WHEAT

The key of the different amount of fertilizers applied in various soils lies in how to determine the level of the soil fertility. According to field fertilizer experiments made by us in many years and sites on the basis of unified design, we belive that , the content of available phosphorous in soil nutritions is well correlated with the yield:y = 8. 25+ 62. 46logp r = 0.8618* *(y : the percent of the yield, P: the measurement value of the available phosphorous in the soil)So, it is practical to use the content of the available soil phosphorous as one of the indexes of the soil fertility in this province. According to the relationship between the available soil phosphorous and the yield percent, the level of available phosphourous of the soil can he divided into three grades: below 10ppm, between 10 and 20 ppm, and above 20ppm. The corresponding yield percents of these grades are : below 70, between 70 and 90, and above 90.According to different levels of availabl soil phosphorous, three different equations of fertilizer effects are made up, and the best economical fertilizer application amount and the proportion of nitrogen and phosphorous can be calculated and the yield range can be predicted.The suitable application amount of fertilizers in the main production areas of winter wheat in the province can be recommended according to the level of available phosphorous of the soils, the effection equation of phosphate fertilizer , and nitrogenous and phosphate fertilizers. The yield and net profit can also be prodicted.The experimental result indicates the fertilizer fomula applicable for winter wheat in the province macroscopically. It is of universal significance in instructing fertilization scientifically in wheat. In the meanwhile, it provides scientific basis for the country to arrange production and allocate fertilizers.