渭北高原典型黑垆土区土壤物理性状及其对小麦产量的影响

2015年在调查渭北高原黑垆土施肥量、产量和土壤性状(紧实度)的基础上,确定了61块冬小麦田为研究对象,分层采集0～50 cm土壤样品,研究了土壤紧实度、容重、水稳性团聚体的变异规律及其与小麦产量、化肥偏生产力的偏相关关系.结果表明: 0～50 cm土层土壤紧实度和水稳性团聚体具有弱变异特征,变异系数分别为9.9%、4.9%;容重具有中等变异特征,变异系数为27.5%.小麦产量、化肥偏生产力与0～50 cm土壤紧实度均呈极显著负相关,其中与0～10、10～20和20～35 cm土层相关性状的关系更密切.小麦产量与土壤紧实度、容重、>0.25 mm水稳性团聚体含量、有机质的多元回归分析表明,产量最终取决于土壤紧实度和有机质两个关键因素.因此,提高土壤有机质含量,降低表层(0～20 cm)和犁底层(20～35 cm)土壤紧实度是提高渭北高原黑垆土区小麦产量的关键.

Soil physical properties and its effects on wheat yield in typical dark loessial soil on Weibei Plateau,China.

Based on the investigations of fertilizer application rates, wheat yield and soil properties (soil compaction) of dark loessial soil on Weibei Plateau in 2015, soil samples from 0-50 cm depth were collected in 61 winter wheat fields. The variability of soil compaction, bulk density, water-stable aggregates and their partial correlations with wheat yield and partial factor productivity were analyzed. The results showed that soil compaction and water-stable aggregates in 0-50 cm depth had weak variability, with the variation coefficients of 9.9% and 4.9%, respectively. Soil bulk density had moderate variability, with the variation coefficient of 27.5%. Wheat yield and fertilizer partial factor productivity were negatively correlated with soil compaction, which were more closely correlated in soil depths of 0-10 cm, 10-20 cm and 20-35 cm. Results from multiple regression showed that wheat yield was determined by soil compaction and organic matter. The improvement of soil organic matter and reduction of soil compaction in top soil (0-20 cm) and plough pan layer (20-35 cm) would be the key strategies to enhance wheat yield in dark loessial soil on Weibei Plateau.