马铃薯全膜双垄连作种植对土壤质量的影响

Potato is one of the dominant crops in semiarid area, the middle of Gansu province, China. The production and water use efficiency (WUE) of potato is greatly improved with the extensively application of the fully mulched alternating narrow and wide ridges planting technology and the auto plastic film machine. Therefore, the planting acreage of potato in area is increased with years. Continuous cropping cultivation of potato is not uncommon in this area. which is due to: the government－led scale planting，the limited total cultivatable area and the impracticable potato-maize rotation pattern (insufficient water and heat) . Uncovered continuous planting led to the soil deterioration and crop development suppression. Application of plastic film can improve microenvironment around plant roots and the hydrothermal ecological system of soil, correspondingly improves the soil quality. Therefore, under the fully mulched alternating narrow and wide ridges planting，the impact of the continuous planting of potato on soil quality is a scientific proposition worthy of further study. This project is base on the trail of high yield and drought tolerant potato in middle semiarid area of Gansu, China, and the filed location test and the laboratory precision analysis will be used. In this project, variation of physical, chemical and biological characterization of soil under the fully mulched alternating narrow-wide ridges with ridge planting and the fully mulched alternating narrow-wide ridges with furrow planting were analyzed from 1-4 years potato continuous cropping soil, and explore the impact of the completely mulched alternating narrow and wide ridges planting on the farmland soil quality. The results from this study should provide theoretical foundation for improving potato yield, quality and promote the sustainable development of semiarid farmland.

随全膜双垄种植技术及相应耕作覆膜机械的研发应用，陇中半干旱区优势作物马铃薯产量和水分利用效率大幅度提高，种植面积也随之扩大。受政府倡导的规模种植及耕地总面积有限的影响，加之马铃薯-玉米轮作模式不可实现（水分、热量不足），使该区马铃薯连作栽培普遍存在。非覆膜连作种植导致土壤质量变劣，作物生长发育受抑；但覆膜能改善植物根系环境及土壤的水热生态效应，对土壤质量形成有利。因此，全膜双垄种植模式下，马铃薯连作对土壤质量的影响是值得深入研究的科学命题。项目以在陇中半干旱区实施的马铃薯抗旱增产试验为基础，拟采用大田定位试验与实验室精确分析的研究方法，通过对全膜双垄垄播和全膜双垄沟播种植下马铃薯1-4年连作对土壤养分吸收运移规律、盐分积累动态以及土壤物理、化学、生物学特性等进行深入研究，探究马铃薯全膜双垄连作种植对农田土壤质量的影响。以期为提高马铃薯产量、品质，保持半干旱区农田可持续生产提供理论依据。

探究了5种沟垄覆膜及平畦不覆膜（CK）种植模式下马铃薯(Solanum tuberosum L.) 1-4年连作对土壤质量的影响及其机理。结果表明，连作后沟垄覆膜土壤细菌、放线菌、好气性固氮菌、嫌气性固氮菌、硝化细菌和反硝化细菌数量均显著高于平畦不覆膜，而真菌数量则降低，真菌/细菌（F/B）值下降；随连作年限延长，沟垄覆膜土壤F/B值始终较低，以全膜垄播、全膜沟播和半膜垄播最低；且全膜覆盖低于半膜覆盖，垄播低于沟播；以全膜垄播土壤F/B值最低，半膜垄播次之。.采用Illumina MiSeq技术分析连作马铃薯根际土壤真菌和细菌多样性和系统发育结果表明，连作土壤真菌分属于4个门，20个纲，48个目，156个属；子囊菌门(Ascomycota)为各处理的优势门，粪壳菌纲(Sordariomycetes)为优势菌纲；半膜垄播的子囊菌门高达88.7%，而全膜垄播最低；平畦不覆膜、平畦覆膜、全膜沟播和半膜沟播土壤优势属为镰孢菌属(Fusarium)，而全膜垄播和半膜垄播为被孢霉属(Mortierella)，其镰孢菌(Fusarium)含量最低。半膜垄播、平畦不覆膜、半膜沟播土壤真菌群落结构具有相似性聚为一类，全膜垄、沟播与平畦覆膜真菌组成相似聚为一类。连作土壤细菌多样性和丰富度高于真菌，连作土壤细菌分属于439个属，优势属为Subgroup_6_norank，在垄播土壤中最高。全膜覆盖土壤细菌多样性和丰富度均最高；平畦覆膜和平畦不覆膜细菌组成聚为一类，半膜垄播、半膜沟播、全膜垄播和全膜沟播细菌组成聚为一类。全膜、半膜垄播和半膜沟播土壤镰孢菌含量较低，而平畦覆膜、平畦不覆膜和全膜沟播土壤镰孢菌含量较高；说明全膜、垄播方式更能促进细菌而抑制真菌的繁殖，并能抑制镰孢菌繁殖，可预防镰孢菌引起的马铃薯干腐病，有利于土壤质量的改善。.全膜覆盖和半膜垄播改善了土壤水热状况，使土壤微生物多样性更为丰富；增强了土壤过氧化氢酶、蔗糖酶、脲酶、碱性磷酸酶和蛋白酶活性；提高了N、P、K及Cu、Zn等利用率；化感物质种类和含量降低，如甲醇、乙酸乙酯、正己烷组分化感物质以CK最高；使连作马铃薯出苗率、地上部生物产量较高，根系发育良好；改善了马铃薯产量性状，提高了薯块贮藏品质，其干物质、淀粉、还原糖、可溶性蛋白、氨基酸、Vc含量均增加，而有机酸含量降低；1℃贮藏温度更有利于保持较高薯块品质。