酸性红壤中磷高效大豆新种质的磷营养特性

Phosphorus nutrition characters for new soybean germplasms with high phosphorus efficiency in acid red soils

采用一系列磷高效大豆新种质及对照材料,在华南酸性红壤地区3种不同磷水平的代表性土壤上,分春、夏两季研究了不同大豆品种的磷营养特性,探讨了不同大豆品种(系)在不同磷水平土壤上的最佳施磷量及其经济效益。结果表明,1)土壤有效磷含量是影响酸性红壤地区大豆生产的重要因素,无论从地上部生物量、磷吸收量还是产量来看,所有供试品种均表现出高磷>中磷>低磷土壤的趋势。2)施磷对低肥力土壤上大豆产量的影响较大,对中等肥力土壤影响较小,而对高肥力土壤,施磷肥反而造成大豆减产;过量施用磷肥会造成大豆对磷的"奢侈吸收"。3)大豆的磷营养特性具有显著的基因型差异,因而需要不同磷养分管理方式。4个磷高效大豆新种质在低肥力土壤上仅需施用少量磷肥,在中、高肥力土壤上不需施磷即可满足生长需要。经济效益分析结果表明,磷高效品种无论在低肥力还是在中、高肥力土壤上,其纯收入均远高于本地和国家大豆区域试验对照品种。

Several P efficient and inefficient soybean cultivars were employed to investigate P nutrition characters,the optimal P application amounts and their economic benefits in the soils with three different fertilities in spring and summer seasons,respectively.The results show that soil P availability is an important limiting factor for soybean production in acid red soils,and biomasses,P uptakes and yields of the tested soybean germplasms are in the order of high medium low P soils.Soybean yields in low P soils are significantly affected by the phosphorus application,while much less in medium P soils and even negatively in high P soils.Furthermore,excess P fertilization could result in a ＇luxury absorption＇.There are significantly genotypic variations on P nutrition characters of soybeans.Therefore,different P fertilizations should be employed to different soybean germplasms.Slight P application in low P soils,no P application in medium,and high P soils could meet the demand for the growth of the four new P efficient soybean germplasms.The results from economic analysis indicate that net incomes of P efficient soybean cultivars are much higher than those of local and control cultivars.