秸秆还田方式对盐碱土壤微观结构和理化性质的影响  

Effects of Different Straw Returning Methods on Changes of Soil Structure in Saline-alkali Soil

作　　者：张曼玉 杨海昌[1] 张凤华[1] 罗艳琴 于善超 孙静 曹政 ZHANG Man-yu;YANG Hai-chang;ZHANG Feng-hua;LUO Yan-qin;YU Shan-chao;SUN Jing;CAO Zheng(Shihezi University,the Key Laboratory of Oasis Eco-agriculture,Xinjiang Production and Construction Crops,Shihezi 832003,Xinjiang,China)

机构地区：[1]石河子大学新疆生产建设兵团绿洲生态农业重点实验室,新疆石河子832003

出　　处：《节水灌溉》2022年第5期65-70,共6页Water Saving Irrigation

基　　金：国家自然科学基金项目(4216070089);兵团科技攻关项目(2019AB038);石河子大学青年创新人才计划项目(CXPY201910);石河子大学科研项目(ZZZC201918A)。

摘　　要：秸秆还田是西北地区普遍存在的一种改善土壤质量的农作措施之一。为明确秸秆不同还田方式对新疆盐碱土微观结构和理化性质的影响,于2020年进行田间试验,设置以不还田(CK)为对照,棉花秸秆翻压还田(H1)、油菜秸秆翻压还田(H2)、棉花秸秆覆盖还田(F1)、油菜秸秆覆盖还田(F2)共5个处理,分析0~20 cm土层电导率、含水量、有机质和团聚体粒径分布变化,并结合扫描电镜(SEM)探究其土壤微观结构变化。结果表明:较CK,H1、H2处理随着还田时间的增加电导率逐渐降低,含水量逐渐增加,效果优于F1、F2处理。第75 d,H1、H2处理电导率分别降低了5.30%和3.89%,含水量增加了8.93%和7.85%。相比CK,H1、H2处理土壤有机质分别增加了30.90%、29.80%。相比CK,H1、H2处理降低了土壤中小于0.053 mm团聚体比例,增加了0.25~2.00mm团聚体的比例。秸秆翻压还田(H1、H2处理)相较于秸秆覆盖还田(F1、F2处理),土壤片状微观结构增多,颗粒之间由面与面接触转变为直接点接触,增加土壤孔隙数量。综上,秸秆翻压还田较覆盖还田更有利于改善土壤颗粒微观结构和土壤团聚体粒径组成,增强降盐保水的作用。为新疆地区秸秆还田提供理论支撑。Straw returning is one of the common agricultural measures to improve soil quality in Northwest China. In order to clarify the effects of different straw returning methods on the microstructure and physicochemical properties of saline-alkali soil in Xinjiang. In this study, a field experiment was carried out in 2020. A total of 5 treatments, including the treatment of non-returning field as the control, cotton straw soil-turning and returning(H1), rape straw soil-turning and returning(H2), cotton straw mulching and returning(F1), and rape straw mulching and mulching(F2) were set up to analyze the changes of electrical conductivity, water content, organic matter and particle size distribution of aggregates in 0~20 cm soil layer. Scanning electron microscopy(SEM) was used to investigate the changes of soil microstructure. The results showed that compared with CK, the conductivity of H1 and H2 treatments decreased gradually with the increase of returning time and the water content gradually increased, and the effects were better than those of F1 and F2 treatments, respectively. On the75th day, the conductivity of H1 and H2 treatments decreased by 5.30% and 3.89%, and the water content increased by 8.93% and 7.85%,respectively. Compared with CK, soil organic matter in H1 and H2 treatments increased by 30.90% and 29.80%, respectively. In addition, H1and H2 treatments reduced the proportion of aggregates <0.053 mm in soil, and the proportion of aggregates of 0.25~2.00 mm was increased by 3.71% and 4.60%, respectively. Compared with the treatments of F1 and F2, the treatments of H1 and H2 increased the soil flake microstructure, the particles changed from surface to surface contact to direct point contact, and the number of soil pores was increased. In conclusion, straw soil-turning is more conducive to improving soil particle microstructure and soil aggregate particle size composition than mulching, and enhances the effect of salinity reduction and water retention. The study provides theoretical support for straw retur

关 键 词：盐碱土改良 秸秆还田方式 翻压还田 覆盖还田 棉花秸秆 油菜秸秆 土壤结构 土壤团聚体 

分 类 号：S287[农业科学—农业水土工程]