覆盖栽培对渭北旱地冬小麦生产力及土壤肥力的影响

Effects of three mulching modes on winter wheat productivity and soil fertility in dryland of Weibei Rainfed Area

【目的】覆盖栽培可以有效地改善土壤物理、化学及生物学特性,对土壤质量与作物生产力的持续提高具有重要作用。本研究通过3年田间定位试验,比较了渭北旱地几种覆盖栽培方式下冬小麦生产力及土壤肥力状况,以最大化地发挥覆盖措施的作用和效益。【方法】本试验于2014年9月—2017年6月在陕西富平综合试验站进行,共设4个处理,包括传统栽培(CK)、秸秆覆盖(NPS)、地膜覆盖(NPP)和垄沟覆盖(RFPS),每个处理重复3次,完全随机排列设计。于冬小麦收获期采集植株样品及表层(0—20 cm)和亚表层(20—40 cm)土壤样品,分析冬小麦生产力、土壤养分、有机碳、活性有机碳及酶活性的变化。【结果】与CK相比,RFPS、NPP和NPS产量分别显著增加了51.8%、41.3%和13.7%,水分利用率分别提高了40.9%、34.0%和11.2%,处理之间差异显著(P<0.05);3种覆盖栽培方式均提高了冬小麦籽粒和秸秆氮磷钾吸收量,尤其是RFPS和NPP处理(P<0.05)。RFPS处理较CK显著(P<0.05)提高了表层土壤全量氮磷钾(6.5%、4.5%和8.0%)、速效氮磷钾(46.1%、37.8%和19.5%)、有机碳(5.1%)、活性有机碳(15.1%)含量及3种酶(蔗糖酶、脲酶和磷酸酶)活性(24.6%、34.6%和27.4%),增幅明显高于NPP与NPS处理,且明显改善了亚表层土壤质量;NPP处理表层土壤蔗糖酶活性较CK显著(P<0.05)提高了9.6%,0—40 cm土层氮磷钾、有机碳及其他酶活性差异较小;NPS处理表层土壤速效氮磷钾含量较CK显著(P<0.05)提高了22.7%、19.9%和15.0%,有机碳提高了4.1%,活性有机碳提高了12.5%,3种酶活性分别提高了12.0%、15.5%和12.0%,且一定程度上改善了亚表层土壤质量,但对0—40 cm土层全量氮磷钾含量影响较小。【结论】垄沟覆盖栽培方式对提高渭北旱地冬小麦生产力及土壤肥力水平具有显著效果,可在当地农业生产中推广使用。

[Objectives]Mulching cultivations can effectively improve soil physic-chemical and biological characteristics, which have played important roles in continuous improvement of soil quality and crop productivity. In this experiment, we compared the effects of several mulching ways in dryland of Weibei Rainfed Area, to make the best use of these measurements on improving crop productivity and soil fertility in this area.[Methods]The experiment was conducted in winter wheat from September 2014 to June 2017 in Fuping Experimental Station, Shaanxi Province. There were four treatments, no mulching （CK）, mulched with straw （NPS）, plastic film （NPP） and ridge-furrow with plastic film and straw mulch （RFPS）. At harvest, the soil samples of 0-20 cm and 20-40 cm depth were collected for analyzing soil nutrients, organic carbon （SOC）, liable organic carbon （LOC） and enzyme activities, and wheat samples were collected for determining wheat productivity.[Results]Compared with CK, the yields of the RFPS, NPP and NPS treatments were significantly increased by 51.8%, 41.3% and 13.7%, and water use efficiencies were increased by 40.9%, 34.0% and 11.2%, respectively （P 〈 0.05）; the effects among the three treatments were significantly different as well. Compared with the CK, mulching cultivations increased N, P and K uptakes of winter wheat, especially in the RFPS and NPP treatments （P 〈 0.05）. The contents of total N, P and K in the surface soil of RFPS were increased by 6.5%, 4.5% and 8.0%, the contents of available N, P and K were increased by 46.1%, 37.8% and 19.5%, SOC content increased by 5.1% and LOC increased by 15.1%, and the activities of invertase, urease and phosphatase increased by 24.6%, 34.6% and 27.4%, respectively （P 〈 0.05）; and all the increases were significantly higher than those of the NPP and NPS （P 〈 0.05）. The NPP treatment increased the invertase activity by 9.6% in surface soil （P 〈 0.05）, but did not increase significantly the contents of soil nutrients, SOC and other enzyme activities in 0-40 cm layer, and even reduced the contents of total N and SOC, compared with the CK. The NPS treatment increased the contents of available N, P and K by 22.7%, 19.9% and 15.0% （P 〈 0.05）, SOC by 4.1% and LOC by 12.5%, and the activities of invertase, urease and phosphatase by 12.0%, 15.5%% and 12.0%, respectively. However, the NPS treatment had little effects on the contents of total N, P and K in 0-40 cm soil layer.[Conclusions]The mode of ridge-furrow with plastic film and straw mulch performs well in increasing winter wheat productivity and soil fertility in dryland of Weibei Rainfed Area, and can be recommended in local agricultural production for the test area.