穴播条件下地膜覆盖及播种量对春小麦土壤水盐分布的影响

[目的]在河套平原开展了地膜覆盖及穴播量对春小麦土壤水盐分布的影响研究,为减轻土壤盐渍化,提高土壤水分利用效率,实现精量化播种,促进地膜春小麦生产提供科学指导。[方法]以穴播不同量(穴播量分别为8粒,10粒,12粒,14粒和16粒)的露地春小麦为对照,监测穴播不同量的地膜春小麦对土壤水分、盐分分布及春小麦产量的影响。[结果]地膜覆盖与露地穴播的土壤水分均随穴播量的增加而降低;且从播种至灌浆期不同穴播量间的差异随着春小麦的生长而增大。相同穴播量下地膜覆盖的土壤水分在孕穗期前高于露地,扬花期后则低于露地;整个生长期地膜覆盖的耗水量略高于露地。地膜覆盖与露地穴播的土壤盐分均随穴播量的增加而降低但无显著差异,相同穴播量下地膜覆盖0—30 cm土层土壤盐分显著低于露地,30 cm土层以下则与露地基本一致。地膜覆盖与露地穴播的土壤水分利用效率均随穴播量的增加而增加,相同穴播量下地膜覆盖的春小麦产量和水分利用效率、水分产出率高于露地,千粒重和经济系数则低于露地。露地穴播的产量及水分产出率均以穴播14粒的最高,地膜覆盖的产量以穴播12粒的最高,水分产出率以穴播10粒的最高。[结论]地膜覆盖可降低0—30 cm土层土壤盐分,提高土壤水分利用效率,河套平原地膜春小麦的适宜穴播量应为当地常规露地条播量的70%至84%,即穴播10至12粒。

Effects of Film Mulching and Sowing Rate on Soil Moisture and Soil Salt Distribution of Spring Wheat Under Hole Sowing

[Objective] The effects of plastic film mulching and hole sowing rate on soil water and soil salt distribution of spring wheat under hole sowing were studied in Hetao Plain, in order to provide scientific guidance for reducing soil salinization, improving soil water use efficiency, realizing precision sowing and promoting plastic film spring wheat production.[Methods] Spring wheat in open field with different hole sowing rate (8, 10, 12, 14 and 16 seeds, respectively) was taken as control, to monitor the effect of spring wheat with film mulching on soil moisture, soil salt distribution and the yields of wheat.[Results] The soil moisture in both film mulched fields and open fields decreased with the increase of hole sowing rate, and the difference of soil moisture among different hole sowing rate from sowing to filling period increased with the growth of spring wheat. Under the same how sowing rate, the soil moisture in film mulched fields were higher than those in open fields before the booting period, while it was lower after flowering period. Soil water consumption of spring wheat with film mulching were slightly higher than those in open fields in the whole growing season. The soil salt in both open fields and film mulched fields decreased with the increase of hole sowing rate, however, there was no significant difference among different hole sowing rates. Soil salt in 0-30 cm soil layer in film mulched fields was significantly lower than those in open fields, but the soil salt below 30 cm soil layer was basically the same as those in open fields under the same hole sowing rate. The soil water use efficiency in both open fields and film mulched fields increased with the increase of hole sowing rate. The yields, water use efficiency and water output rate of spring wheat with film mulching were higher while the thousand grain weight and economic coefficient were lower than those in the open fields under the same hole sowing rate. The yield and water output rate in open fields were the highest with a hole sowing rate by 14 seeds, while the yield in film mulched fields was the highest with a hole sowing rate by 12 seeds, and the water output rate was the highest with a hole sowing rate by 10 seeds.[Conclusion] Film mulching can reduce soil salt in 0-30 cm soil layer and improve soil water use efficiency. The suitable hole sowing rate of spring wheat with film mulching should be 70% to 84% of the local conventional open field strip sowing rate, i. e. 10 to 12 seeds per hole sowing in salinized soil in Hetao Plain.