[关键词]
[摘要]
在调查甘肃引黄灌区玉米产量、施肥量和土壤理化性状基础上,2015年确定60个地块作为研究对象,分层采集0~40 cm土层土壤样品,研究土壤三相比、紧实度、水稳性团聚体含量和有机质含量的变异规律及其与玉米产量、化肥偏生产力的关系。结果表明,0~40 cm土层土壤三相比δ值、土壤紧实度、土壤> 0.25 mm水稳性团聚体含量和有机质含量均呈中等变异特征。土壤紧实度随土层加深而显著增加,土壤三相比δ值、> 0.25 mm水稳性团聚体含量和有机质含量均有随着土层加深而降低的趋势。玉米产量与0~40 cm土层土壤三相比δ值和土壤紧实度呈极显著负相关,与土壤> 0.25 mm水稳性团聚体含量和土壤有机质含量呈极显著正相关;磷肥偏生产力与0~40 cm土层土壤三相比δ值呈极显著正相关,与土壤紧实度呈显著正相关,与土壤> 0.25 mm水稳性团聚体含量和土壤有机质含量呈极显著负相关;氮肥偏生产力与4个指标之间均达不到差异显著水平。玉米产量与土壤紧实度、土壤三相比δ值的关系可用一元二次方程来拟合,与土壤> 0.25 mm水稳性团聚体含量、土壤有机质含量的关系可用一元线性方程来拟合。多元逐步回归分析表明,玉米产量最终取决于土壤> 0.25 mm水稳性团聚体含量和土壤有机质含量两个关键因素。
[Key word]
[Abstract]
Based on the investigations of corn yields,fertilizer application rates and soil physical and chemical properties in Gansu Yellow River irrigation district in 2015, the layered 0~40 cm soil samples were collected as the research object in 60 corn fields for the variability of soil three-phase,compaction,water-stable aggregate, organic matter content and their partial correlations with corn yield and partial factor productivity. The results showed that the averages of soil three-phase δ value,soil compaction, > 0.25 mm water-stable aggregate and organic matter content in 0-40 cm soil showed moderate variability. The soil compaction significantly increased with the increase of soil depth, but the soil three-phase δ value, > 0.25 mm water-stable aggregate and organic matter content decreased with the increase of soil depth. Corn yields were extremely negative correlated with 0~40 cm soil three-phase δ value and soil compaction, but extremely positive correlated with > 0.25 mm water-stable aggregate and organic matter content, significantly. Phosphate partial factor productivity were extremely positive correlated with three-phase δ value, positive correlated with soil compaction, but extremely negative correlated with > 0.25 mm water-stable aggregate and organic matter content 0~40 cm soil depth. There were no significant difference between nitrogen partial factor productivity and the four indexes. The relationships between corn yield and soil compaction, soil three-phase δ value could be fitted by quadratic unary equation, and that of > 0.25 mm water-stable aggregate and organic matter content could be fitted by unary linear equation. The results of multivariate stepwise regression analysis showed that > 0.25 mm water-stable aggregate and organic matter content were the key factors to decide corn yield.
[中图分类号]
S158;S513
[基金项目]
农业农村部公益性行业(农业)科研专项(201503117);甘肃省农业科学院重点研发计划(2020GAAS19)。