秸秆还田与地膜覆盖对土壤理化性状影响

发布时间：2018-05-17 15:03

本文选题：地膜覆盖 + 秸秆还田　；参考：《兰州大学》2017年硕士论文

【摘要】：地膜双垄沟播技术已成为半干旱半湿润黄土高原雨养农业区被大面积推广用于作物增产的种植模式,其具有覆盖抑蒸、垄沟播种、集雨保温等优点。玉米秸秆富含有机物质,其能作为输入土壤的再生生物资源帮助作物生长。然而由于黄土高原地区水温条件不适宜和降雨稀少等原因腐解玉米秸秆所需时间较长,因此我们把地膜双垄沟播技术与秸秆还田有机结合起来集两者之长处,找到了一种既能提高土壤肥力又能增加作物产量的种植模式。但在该种植模式下是否会影响土壤理化性状,土壤理化性状和作物产量的增加不能以牺牲土壤理化性状为前提。土壤团聚体、pH值、容重等均是评估土壤理化性状重要指标。本实验于2015年分别在甘肃省会宁县和榆中县进行,实验设置四个处理:对照(CK)、秸秆还田(S)、覆膜(M)、秸秆还田+覆膜(SM),分别重复三次,随机区组排列。于2015年7月及收获时采样,测定指标有pH、全氮、矿化氮、土壤团聚体水稳性、MWD、耕层土壤含水量、微生物碳氮、有机碳、容重和玉米生物量。主要得出了以下结果:(1)地膜覆盖在籽粒产量和根生物量上增产效果显著。会宁实验地较不覆膜处理在籽粒产量和根生物量上增产幅度分别为83%和34%,榆中实验地增产幅度分别为140%-38%。秸秆还田对其无显著影响。(2)秸秆还田能显著影响全氮含量,较不秸秆还田处理而言增加幅度为18-30%;能显著影响有机碳含量,增加幅度为12-40%;能显著影响微生物量碳、氮含量,增加幅度分别为42-117%、16-102%;能显著影响土壤容重,减少幅度为4-9%。(3)地膜覆盖能显著影响硝态氮含量,较不覆膜处理而言增加幅度为73-325%;能显著影响土壤pH,减少幅度为0.19-0.35;能显著影响土壤容重,增加幅度为6-7%。。pH值与硝态氮含量存在强相关性。(4)秸秆还田能显著增加土壤大团聚体(0.25 mm)比重,较不秸秆还田处理而言增加幅度为10-37%;地膜覆盖能显著增加土壤大团聚体(0.25 mm)比重,较不覆膜处理增加幅度为8-34%。秸秆还田对平均质量直径(MWD)影响不显著,地膜覆盖影响显著,秸秆还田与地膜覆盖对其有交互作用。在覆膜前提下不秸秆还田处理MWD增加幅度较秸秆处理MWD增加幅度更大,在秸秆还田前提下不覆膜较对照(CK)MWD显著增加,而覆膜(M)与秸秆还田+覆膜(SM)之间差异较小或不存在显著性。通过上述实验我们得出秸秆还田与地膜覆盖均能显著增加土壤大团聚体(0.25 mm)比重,土壤大团聚体的增加有利于土壤孔隙性良好,土质疏松、耕性良好,土温协调稳定,保肥供肥性能强等,而秸秆还田与地膜覆盖均能显著增加土壤大团聚体比重可能是与根生物量及微生物活性增加有关;地膜覆盖显著减小pH,可能破坏土壤理化性状,影响微生物及农田作物的生长发育等,pH减小与土壤中硝态氮的富集有关;地膜覆盖会增加土壤容重即土壤致密性增加,可会直接或间接影响作为生长发育。秸秆还田与地膜覆盖的耕作模式会部分影响土壤理化性状,在进行耕作时可以农田覆膜可以隔年实施一次,有利于土壤理化性状的恢复。
[Abstract]:The double ridge furrow sowing technology has been widely used in the semi arid and semi humid loess plateau in the rain raising agricultural area, which has been widely used to increase the yield of crops. It has the advantages of covering the steaming, furrow sowing, and collecting rain and heat preservation. The corn straw is rich in organic matter, which can be used as the regenerated biological resources of the soil to help the crop growth. It takes a long time to decompose corn straw for the reasons that the water temperature is not suitable and the rainfall is scarce in the plateau. Therefore, we combine the double ridge furrow seeding technique with the straw to the field, and find a planting pattern which can increase the soil fertility and increase the crop yield. Soil physical and chemical properties, soil physical and chemical properties and increase of crop yield can not be taken as the premise of sacrificing soil physical and chemical properties. Soil aggregate, pH value and bulk density are all important indexes for evaluating soil physical and chemical properties. The experiment was carried out in Huining county and Yuzhong County of Gansu Province in 2015 respectively. The experiment set up four treatments: control (CK), straw return Field (S), film mulching (M), straw returning and film mulching (SM) were repeated three times in random area. In July 2015 and harvest time, samples were sampled, and the indexes were pH, total nitrogen, mineralized nitrogen, soil aggregate water stability, MWD, soil water content, microbial carbon and nitrogen, organic carbon, bulk density and corn biomass. The main results were as follows: (1) mulched in the seed film The effect of grain yield and root biomass on yield increased significantly. The yield increased by 83% and 34% on Grain Yield and root biomass in the experimental area of Huining, and there was no significant effect on the increase of yield in Yuzhong. (2) the total nitrogen content could be significantly affected by straw returning. The addition of 18-30% can significantly influence the content of organic carbon and increase the range of 12-40%, which can significantly affect the amount of carbon and nitrogen of microorganism, and the increase of nitrogen content is 42-117%, 16-102%, which can significantly affect the soil bulk density, and the decrease range is 4-9%. (3) film mulching can significantly affect the nitrate nitrogen content, and the increase is 73-325% compared with the non plastic film treatment. The effect of soil pH was reduced to 0.19-0.35, which could significantly affect soil bulk density, the increase of 6-7%..PH value was strongly correlated with nitrate nitrogen content. (4) straw returning could significantly increase the proportion of soil large aggregate (0.25 mm), compared with no straw returning treatment, the increase was 10-37%, and film mulching could significantly increase soil aggregate (0.2 The proportion of 5 mm) was not significantly increased by 8-34%. straw returning to the average mass diameter (MWD), and the effect of Mulching on the mulching was significant. The mulching film (CK) MWD increased significantly, while the difference between the mulching (M) and the straw mulching (SM) was small or not significant. Through the above experiments, we concluded that the proportion of soil large aggregates (0.25 mm) could be significantly increased by the straw returning and mulching, and the increase of large soil aggregates was beneficial to soil porosity, soil porosity and tillage. Well, the soil temperature is coordinated and stable, and the performance of fertilizer and fertilizer is strong, while the proportion of straw returning and film mulching can significantly increase the proportion of soil large aggregate, and the soil mass and microbial activity may be increased. The film mulching can significantly decrease pH, may destroy soil physical and chemical properties, affect the growth and development of microorganism and crop, and pH decrease with soil. The enrichment of soil bulk density, that is, the increase of soil bulk density, that is, the increase of soil density, which can directly or indirectly affect the growth and development. The tillage pattern of straw returning and mulching will affect the physical and chemical properties of soil partly. Recovery.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S316;S141.4

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