A better understanding of soil carbon(C)distribution within aggregate fractions is essential to evaluating the potential of no-till for sustaining productivity and protecting the environment.A meta-analysis on 744 com...A better understanding of soil carbon(C)distribution within aggregate fractions is essential to evaluating the potential of no-till for sustaining productivity and protecting the environment.A meta-analysis on 744 comparisons from 34 studies was conducted to determine the effects of three different tillage treatments(conventional mouldbould ploughing tillage(CT),reduced tillage(RT)and no tillage(NT))on water-stable aggregate size distribution,soil C concentration in aggregate fractions.The meta-analysis indicates that compared with CT treatment,NT/RT significantly(P<0.05)increases macro-aggregate above 20 cm by 20.9%-82.2%(>2.00 mm)and 5.9%-19.1%(0.25-2.00 mm),whereas NT/RT significantly reduces micro-aggregate and silt clay fractions above 20 cm.NT/RT significantly(P<0.05)increases the SOC in macro-aggregate(>0.25 mm)and micro-aggregate(<0.25 mm)size classes above 20 cm soil depth compared with CT.The results suggest that soil sampling depth should be considered to evaluate the influence of tillage systems on the distribution of soil aggregate,and the content of aggregate-associated C content.展开更多
通过对黑土坡耕地免耕、少耕与传统耕作土壤物理性状全生育期观测，比较研究土壤结构和导水性状季节变化差异及其与水土流失的关系。结果表明，表层0～20 cm土壤，免耕土壤容重全生育期维持在1.20～1.30 g cm^-3，变化小，大于0.25 mm...通过对黑土坡耕地免耕、少耕与传统耕作土壤物理性状全生育期观测，比较研究土壤结构和导水性状季节变化差异及其与水土流失的关系。结果表明，表层0～20 cm土壤，免耕土壤容重全生育期维持在1.20～1.30 g cm^-3，变化小，大于0.25 mm的水稳性团聚体含量（WR0.25）和平均重量直径（MWD）高于传统耕作，初始和稳定入渗速率均高于少耕和传统耕作，土壤含水量分别较少耕和传统耕作高4.7和4.4个百分点，较传统耕作分别减少地表径流和土壤流失量86%和100%；少耕除夏季各项性状均介于免耕和传统耕作之间，夏季垄沟深松后，垄沟土壤容重显著降低，较免耕和传统耕作降低0.15 g cm^-3以上，提高土壤初始入渗速率30%以上，较传统耕作减少水和土壤流失量20%和40%。传统耕作土壤容重，垄台由播种时的0.91 g cm^-3增加至收获时的1.23 g cm^-3，垄沟一直维持在1.30 g cm^-3左右，WR0.25、MWD、土壤稳定入渗速率、含水量均较低，全生育期10%的雨水流失，土壤流失量615 t km^-2 a^-1。免耕土壤结构稳定，蓄水保水最佳，为效果显著的水土保持耕作措施，少耕也有一定的保水保土作用；免耕和少耕均能够改善土壤物理性状。展开更多
以旱作玉米地为研究对象,对免耕与传统耕作的农田积沙量、地表不同高度间积沙曲线、表层1 cm 深土壤粒径组成等内容进行了重点观测分析。结果表明:免耕对减少旱作玉米农田就地起沙的贡献率是非常巨大的,间接反映出沙质旱耕农田是很主要...以旱作玉米地为研究对象,对免耕与传统耕作的农田积沙量、地表不同高度间积沙曲线、表层1 cm 深土壤粒径组成等内容进行了重点观测分析。结果表明:免耕对减少旱作玉米农田就地起沙的贡献率是非常巨大的,间接反映出沙质旱耕农田是很主要的沙源地之一,而以免耕对农田就地起沙的防效特别突出,在干旱风沙区是一项很值得推广的农耕措施。展开更多
基金National Natural Science Foundation of China(31860361)The National Natural Science Foundation of Ningxia Hui Autonomous Region(2019AAC03055)+1 种基金The Science and Technology Young Talent Project of Ningxia Hui Autonomous Region(TJGC2019075)The Young Project from Ningxia University。
文摘A better understanding of soil carbon(C)distribution within aggregate fractions is essential to evaluating the potential of no-till for sustaining productivity and protecting the environment.A meta-analysis on 744 comparisons from 34 studies was conducted to determine the effects of three different tillage treatments(conventional mouldbould ploughing tillage(CT),reduced tillage(RT)and no tillage(NT))on water-stable aggregate size distribution,soil C concentration in aggregate fractions.The meta-analysis indicates that compared with CT treatment,NT/RT significantly(P<0.05)increases macro-aggregate above 20 cm by 20.9%-82.2%(>2.00 mm)and 5.9%-19.1%(0.25-2.00 mm),whereas NT/RT significantly reduces micro-aggregate and silt clay fractions above 20 cm.NT/RT significantly(P<0.05)increases the SOC in macro-aggregate(>0.25 mm)and micro-aggregate(<0.25 mm)size classes above 20 cm soil depth compared with CT.The results suggest that soil sampling depth should be considered to evaluate the influence of tillage systems on the distribution of soil aggregate,and the content of aggregate-associated C content.
文摘通过对黑土坡耕地免耕、少耕与传统耕作土壤物理性状全生育期观测，比较研究土壤结构和导水性状季节变化差异及其与水土流失的关系。结果表明，表层0～20 cm土壤，免耕土壤容重全生育期维持在1.20～1.30 g cm^-3，变化小，大于0.25 mm的水稳性团聚体含量（WR0.25）和平均重量直径（MWD）高于传统耕作，初始和稳定入渗速率均高于少耕和传统耕作，土壤含水量分别较少耕和传统耕作高4.7和4.4个百分点，较传统耕作分别减少地表径流和土壤流失量86%和100%；少耕除夏季各项性状均介于免耕和传统耕作之间，夏季垄沟深松后，垄沟土壤容重显著降低，较免耕和传统耕作降低0.15 g cm^-3以上，提高土壤初始入渗速率30%以上，较传统耕作减少水和土壤流失量20%和40%。传统耕作土壤容重，垄台由播种时的0.91 g cm^-3增加至收获时的1.23 g cm^-3，垄沟一直维持在1.30 g cm^-3左右，WR0.25、MWD、土壤稳定入渗速率、含水量均较低，全生育期10%的雨水流失，土壤流失量615 t km^-2 a^-1。免耕土壤结构稳定，蓄水保水最佳，为效果显著的水土保持耕作措施，少耕也有一定的保水保土作用；免耕和少耕均能够改善土壤物理性状。
文摘以旱作玉米地为研究对象,对免耕与传统耕作的农田积沙量、地表不同高度间积沙曲线、表层1 cm 深土壤粒径组成等内容进行了重点观测分析。结果表明:免耕对减少旱作玉米农田就地起沙的贡献率是非常巨大的,间接反映出沙质旱耕农田是很主要的沙源地之一,而以免耕对农田就地起沙的防效特别突出,在干旱风沙区是一项很值得推广的农耕措施。
基金Challenge Program on Water & Food-Conservation agriculture for the dry-land areas of the Yellow River Basin(CPWFYRB200504)国家"十一五"科技攻关计划重大项目(2006BAC01A07)
