不同厚度秸秆隔层对河套灌区盐碱土壤温度、水分和食葵产量的影响

[目的]研究不同厚度秸秆隔层对盐碱地食葵农田土壤温度、水分动态变化及产量的影响,为河套灌区筛选适宜盐碱地食葵生长的合理厚度秸秆隔层措施提供依据.[方法]2015—2017年在内蒙古河套地区典型盐碱农田设置了4个不同厚度的秸秆隔层,分别为CK(无秸秆隔层)、S3(厚度3 cm秸秆隔层)、S5(厚度5 cm秸秆隔层)和S7...

Effects of Straw Interlayer with Different Thickness on Saline-Alkali Soil Temperature,Water Content,and Sunflower Yield in Hetao Irrigation Area

【Objective】The effects of different thickness of straw interlayer on soil temperature, water content dynamic change and crop yield of sunflower field in saline-alkali land were studied to provide a basis for selecting reasonable thickness straw interlayer measures suitable for the growth of sunflower in Hetao irrigation area. 【Method】 From 2015 to 2017, 4 straw interlayers of different thicknesses were set up in the typical saline-alkali farmland in the Hetao area of Inner Mongolia, namely CK (no straw interlayers), S3 (straw interlayers with a thickness of 3 cm), S5 (straw interlayers with a thickness of 5 cm), and S7 (straw interlayer with a thickness of 7 cm), to study the effects of different thickness of straw interlayer on the dynamic changes of soil temperature, water content, and sunflower yield during the growth period of sunflower under. 【Result】The straw interlayer treatment (S3, S5 and S7) significantly increased the soil temperature of 0-40 cm soil layer during the whole growth period of sunflower. Among them, compared with CK treatment, the soil temperature in sunflower seedling stage significantly increased by 0.7℃, 0.6℃, and 0.5℃, respectively, from 2015 to 2017 (P<0.05), and the increase in temperature gradually decreased with the increase of straw burying time. There was a significant difference between straw interlayer treatments during flowering period, among which S5 and S7 treatments increased by 0.4℃ and 0.6℃, respectively, compared with CK treatment in average for 3 years (P<0.05); 40-50 cm soil layer straw interlayer treatment showed a trend of increasing temperature in seedling and bud stage of sunflower, and showed a cooling trend in the later growth period. Under different treatments, the soil temperature during the whole growth period of sunflower decreased as the soil layer deepens, and there was a very significant positive correlation between soil temperature and atmospheric temperature. The distribution range of R² value in three years was 0.628-0.735. Straw interlayer treatments enhanced the sensitivity of soil temperature to atmospheric temperature, and the response of soil temperature to atmospheric temperature decreases with the increase of straw burying time. The interaction between different straw interlayer treatments and different irrigation periods also had significant effects on soil water content (P<0.05). Straw interlayer treatment could reduce the average soil water content of the 0-40 cm soil layer before irrigation and after harvest. Among them, the S7 treatment had the largest reduction, and the three-year average decreased by 7.9% and 5.4% (P<0.05), compared with the CK treatment; after irrigation, the average soil water content of S3, S5 and S7 treatments increased by 2.3%, 3.4%, and 3.6%, respectively, compared with CK treatment for 3 years (P<0.05). The straw interlayer treatment could promote the growth of sunflower and increase the yield of sunflower, and improve irrigation water productivity and water use efficiency, among which 5 and 7 cm thick straw interlayer treatments increased the most and had the largest increase, but there was no significant difference between the two treatments (P>0.05). 【Conclusion】Straw interlayers of different thicknesses could increase the soil temperature in the 0-40 cm soil layer during the growth period of sunflower, and the increase of temperature decreased with the increase of the straw burying time. The difference between different treatments was significant during the flowering stage. In addition, the straw interlayer treatment could improve the average soil water content of 0-40 cm soil after irrigation, and provide a suitable growth environment for sunflower. Considering soil temperature and crop water use efficiency, straw separation with thickness of 5 cm is the most suitable for promotion and application in Hetao irrigation area of Inner Mongolia.