不同种植模式下豆科绿肥对土壤改良效果的影响

为探明豆科绿肥还田对土壤改良效果和作物生物产量的影响,本研究选取玉米(Zea mays)、油菜(Brassica campestris)、大麦(Hordeum vulgare)、燕麦(Avena sativa)为间混作/轮作对象,将花生(Arachis hypogaea)、鹰嘴豆(Cicer arietinum)、白花草木樨(Melilotus albus)作为主要豆科绿肥进行田间试验,利用土壤浅层有机质、氮、磷、钾等养分含量的变化及田间作物地上生物产量的表现,比较不同种植模式下豆科绿肥对土壤改良效果的影响。结果表明:1)与作物单作相比,豆科绿肥与玉米、油菜间混作以及轮作均可提高土壤表层有机质、全氮及碱解氮质量分数,混作对土壤表层全钾质量分数影响较小,轮作还可提高土壤表层全磷、有效磷质量分数;另一方面,间混作群体结构在土壤肥力的改善效果方面也起到一定的作用。2)与试验前土壤养分质量分数相比,白花草木樨+大麦混作并翻压还田模式土壤有机质、全氮、全磷、全钾、碱解氮、有效磷分别提高了40.43%、50.00%、10.00%、27.93%、76.75%、45.13%;玉米+花生间作模式土壤养分改善效果次之。3)玉米、油菜和白花草木樨地上生物产量较其单作分别提高了23.19%、16.68%和27.31%。因此,采用豆科绿肥+禾本科牧草混作并翻压还田、玉米+花生间作的种植模式可有效改善乌尔禾地区农田的土壤质量,并兼顾其他农作物生产,可提高该地区农业的可持续发展能力。

Effects of improving soil fertility by planting different leguminous green manure plants under different mixed cropping patterns

Field experiments were conducted in Zhaosu,Xinjiang,from 2017 to 2018 to illuminate the influence of green legume manure plants peanuts,chickpeas,and white sweet clover on soil nutrient concentrations and the aboveground biomass of selected intercropped/rotated crops corn,oilseed rape,barley,and oat.The improvement of soil nutrients was compared under different planting patterns by measuring changes in soil organic matter,nitrogen,phosphorus,and potassium concentration,aboveground biomass,and land equivalent ratios.The results showed that:(1)Compared with a crop monoculture,the green legume manure plants intercropped with corn,mixed oilseed rape,barley,and oat rotations had improved soil organic matter,total nitrogen,and alkali hydrolyzed nitrogen of the soil surface.However,the planting patterns had little effect on total potassium concentration in the soil surface.Furthermore,the sweet clover+barley and oats rotations improved the total phosphorus and available phosphorus concentration of the soil surface.The spatial structure of intercropped and mixed patterns also affected improvements in soil nutrient concentrations.(2)Compared with the soil nutrient concentration before the field experiment,soil organic matter,total nitrogen,total phosphorus,total potassium,alkali-hydrolyzed nitrogen,and available phosphorus increased by 40.43%,50.00%,10.00%,27.93%,76.75%,and 45.13%,respectively,under the white sweet clover+barley rotation.(3)The aboveground biomass of maize,oilseed rape,and white sweet clover for mixed cropping treatments increased by 23.16%,16.67%,and 27.30%,respectively,when compared with a monoculture.There was a quadratic polynomial function between the increment of aboveground biomass and soil nutrient concentration.Therefore,green legume manures+grass rotations and mulches in the soil,and peanut and corn intercropping improved soil quality by increasing the soil nutrient concentrations of farmlands in Wuerhe area.The planting patterns also produced a crop yield that can provide economic returns.The improvement of soil quality will help to improve the sustainable development of agriculture in this area.