Plastic mulch is commonly used with micro-irrigation in developed countries;however,Chinese farmers use plastic mulch on a vast scale independent of micro-irrigation.For the past three decades,China’s land area in pl...Plastic mulch is commonly used with micro-irrigation in developed countries;however,Chinese farmers use plastic mulch on a vast scale independent of micro-irrigation.For the past three decades,China’s land area in plastic mulch has exceeded the world’s total land area in micro-irrigation.We report results from the water-scarce region of Minqin County,where 87%of Chinese farmers interviewed responded that they use plastic mulch to conserve water and 53%to increase yields.Survey results indicated the desire to conserve water through the use of plastic mulch to be statistically equivalent to the desire to increase yields.Responses to interviews and surveys indicate that farmers perceive water savings of 24-26%when plastic mulch is used.Interview and survey responses suggest farming families are shifting to purchasing wheat from outside the region;a potential import of"virtual water"into this water-scarce region.展开更多
Biochar has been proposed as a soil amendment to reclaim salt-affected soils.However,the evaluation of the different biochar types in these soils is essential due to the significant variation among biochar feedstocks....Biochar has been proposed as a soil amendment to reclaim salt-affected soils.However,the evaluation of the different biochar types in these soils is essential due to the significant variation among biochar feedstocks.In this study,biochars from sugarcane bagasse(SB),orange bagasse(OB),and corncob(CB)were applied alone and in the presence of gypsum(G)to test their potential to remediate a highly degraded saline-sodic soil in Brazil´s Northeast region.For that,we conducted a laboratory column-leaching experiment and a greenhouse study.After the column-leaching test,we analyzed the sodium adsorption ratio(SAR),the electrical conductivity of the saturation extract(ECe),the concentrations of major ions,and the exchangeable sodium percentage(ESP).Maize plants were grown in the leached soil in a greenhouse.Sugarcane-and corncob-derived biochars were more efficient than gypsum in reducing the soil salinity,bringing the indicators below threshold values,and optimizing soil reclamation time.Soil ECe,SAR,and ESP were reduced to 3.42 dS m−1,1.64(mmolc dm−3)0.5 and 4.86%,respectively,in the SB treatment;and to 3.19 dS m−1,0.88(mmolc dm−3)0.5 and 2.53%,respectively,in the CB treatment.Orange bagasse biochar did not effectively reduce the salinity indicators.All biochar treatments improved seed germination and plant growth.The SB,CB,SBG,and CBG treatments increased plant height(478–558%),shoot mass(783–983%),and root mass(386–500%),respectively.Therefore,the application of SB and CB is an effective alternative to remediate saline-sodic soils and to reduce the impact of soil salinity in the environment.展开更多
基金This research was supported by the Tokyo Foundation's Ryoichi Sasakawa Young Leaders Fellowship Fund(SYLFF)The Foundation for Global Scholars.the United States Environmental Protection Agency through grant number SU 835348 to M.V.Santelmann
文摘Plastic mulch is commonly used with micro-irrigation in developed countries;however,Chinese farmers use plastic mulch on a vast scale independent of micro-irrigation.For the past three decades,China’s land area in plastic mulch has exceeded the world’s total land area in micro-irrigation.We report results from the water-scarce region of Minqin County,where 87%of Chinese farmers interviewed responded that they use plastic mulch to conserve water and 53%to increase yields.Survey results indicated the desire to conserve water through the use of plastic mulch to be statistically equivalent to the desire to increase yields.Responses to interviews and surveys indicate that farmers perceive water savings of 24-26%when plastic mulch is used.Interview and survey responses suggest farming families are shifting to purchasing wheat from outside the region;a potential import of"virtual water"into this water-scarce region.
文摘Biochar has been proposed as a soil amendment to reclaim salt-affected soils.However,the evaluation of the different biochar types in these soils is essential due to the significant variation among biochar feedstocks.In this study,biochars from sugarcane bagasse(SB),orange bagasse(OB),and corncob(CB)were applied alone and in the presence of gypsum(G)to test their potential to remediate a highly degraded saline-sodic soil in Brazil´s Northeast region.For that,we conducted a laboratory column-leaching experiment and a greenhouse study.After the column-leaching test,we analyzed the sodium adsorption ratio(SAR),the electrical conductivity of the saturation extract(ECe),the concentrations of major ions,and the exchangeable sodium percentage(ESP).Maize plants were grown in the leached soil in a greenhouse.Sugarcane-and corncob-derived biochars were more efficient than gypsum in reducing the soil salinity,bringing the indicators below threshold values,and optimizing soil reclamation time.Soil ECe,SAR,and ESP were reduced to 3.42 dS m−1,1.64(mmolc dm−3)0.5 and 4.86%,respectively,in the SB treatment;and to 3.19 dS m−1,0.88(mmolc dm−3)0.5 and 2.53%,respectively,in the CB treatment.Orange bagasse biochar did not effectively reduce the salinity indicators.All biochar treatments improved seed germination and plant growth.The SB,CB,SBG,and CBG treatments increased plant height(478–558%),shoot mass(783–983%),and root mass(386–500%),respectively.Therefore,the application of SB and CB is an effective alternative to remediate saline-sodic soils and to reduce the impact of soil salinity in the environment.
