为了探究旧膜二茬及秸秆带状覆盖条件下,马铃薯田的土壤水热特征及增产机制,设置旧膜直播(T1)、秸秆带状覆盖种植带不旋耕(T2)、秸秆带状覆盖种植带旋耕(T3)、新覆膜(T4)和露地平作(CK)5个处理进行田间试验。结果表明:各覆盖处理较CK提...为了探究旧膜二茬及秸秆带状覆盖条件下,马铃薯田的土壤水热特征及增产机制,设置旧膜直播(T1)、秸秆带状覆盖种植带不旋耕(T2)、秸秆带状覆盖种植带旋耕(T3)、新覆膜(T4)和露地平作(CK)5个处理进行田间试验。结果表明:各覆盖处理较CK提高产量14.24%~56.33%、商品薯率1.21%~22.60%及水分利用效率8.28%~55.39%( P <0.05);产量与块茎形成期的单株薯干重正相关( r =0.744),覆盖处理在块茎形成期较CK提高单株薯干重118.0%~720.0%( P <0.05),以T4最高;覆盖处理对马铃薯水热特征有显著影响( P <0.05),T1、T2的降温效应显著小于T3,T3的蓄水保墒效应与T4差异不显著,但显著大于T1、T2及CK。可见,在本试验条件下,秸秆带状覆盖种植带旋耕的产量高于旧膜直播、略低于新覆膜,但蓄水保墒效应与新覆膜相近,同时秸秆带状覆盖种植带旋耕较其余覆盖处理具有较明显的降温增墒效应,有利于促进马铃薯块茎的形成及膨大。展开更多
冻融循环破坏了土的结构,降低了土的力学性能。完成了石灰固化土与纤维加筋固化土的冻融试验、无侧限抗压试验、扫描电镜(scanning election microscopy,简称SEM)观察与核磁共振(nuclear magnetic resonance,简称NMR)测试,探讨冻融循环...冻融循环破坏了土的结构,降低了土的力学性能。完成了石灰固化土与纤维加筋固化土的冻融试验、无侧限抗压试验、扫描电镜(scanning election microscopy,简称SEM)观察与核磁共振(nuclear magnetic resonance,简称NMR)测试,探讨冻融循环对土的强度与微结构的破坏作用,以微结构指标评价土的抗压强度变化。结果表明:石灰固化土与纤维加筋固化土的抗压强度均随冻融次数的增加而降低,土的冻融破坏过程经历了降幅较大、降幅较小、降幅平缓与强度稳定4个阶段;含水率越大,冻融次数越多,纤维对土的增强效果越明显;掺加纤维延缓了微裂隙的形成与发展,降低了裂隙的贯通率;随着冻融次数的增加,孔隙率与孔径均增大,冻胀使得部分小孔隙联通为中孔隙和大孔隙。纤维对土的空间约束作用与筋土摩擦作用使得土的孔隙率与孔隙分布特征变化较小,纤维加筋固化土的强度与抗冻融性能优于固化土。展开更多
An improved straw mulching model may be a sustainable agricultural production technology due to its improvements in soil water and the fertilizer environment by the recycling of waste straw resources.A four-year field...An improved straw mulching model may be a sustainable agricultural production technology due to its improvements in soil water and the fertilizer environment by the recycling of waste straw resources.A four-year field experiment was conducted in a randomized block design on the Loess Plateau of northwestern China in 2015–2019,which aimed to study the effects of straw strip mulching(SSM)and conventional flat planting without mulching(CK)on soil water storage,water consumption characteristics,water use efficiency,precipitation use efficiency,winter wheat growth,economic benefits,and nutrient benefits.The results obtained for the four years showed that the SSM treatment improved soil water storage in the 0–180 cm soil layer over the whole growth period,which was especially obvious in the 0–60 cm soil layer at the jointing and blooming stages.Compared with CK,SSM increased the contribution rate of precipitation to total evapotranspiration and increased it quite significantly by 20.4 percentage points in the earlier growth period.SSM significantly reduced soil water storage consumption in the 0–180 cm soil layer and ultimately reduced evapotranspiration by 11.2 mm during the whole period.In the 0–180 cm soil layer,SSM decreased evapotranspiration by 33.1 mm from the sowing to the jointing stages,but increased it by 19.5 mm from the jointing to the blooming stages.In addition,SSM improved the water use efficiency of grain yield by 21.6%and improved the precipitation use efficiency of grain yield by 18.6%,and it ultimately increased grain yield by 16.5%through improving spike number by 9.5%and kernel number per spike by 8.9%.SSM improved the water use efficiency of biomass yield by 13.5%and the precipitation use efficiency of biomass yield by 9.9%,and it ultimately increased biomass yield by 8.7%and plant height by 6.5%.Furthermore,SSM increased net income by 413 CNY ha–1 and the total amount of straw returned to the field after harvest by 8876–9619 kg ha–1.After returning straw to the field,SSM significantly increased the soil nutrient contents,which could significantly reduce the burden of fertilization by farmers after a few years.Therefore,straw strip mulching technology could probably be a sustainable and potentially useful practice,which could save water and increase efficiency in rainfed winter wheat production.展开更多
文摘为了探究旧膜二茬及秸秆带状覆盖条件下,马铃薯田的土壤水热特征及增产机制,设置旧膜直播(T1)、秸秆带状覆盖种植带不旋耕(T2)、秸秆带状覆盖种植带旋耕(T3)、新覆膜(T4)和露地平作(CK)5个处理进行田间试验。结果表明:各覆盖处理较CK提高产量14.24%~56.33%、商品薯率1.21%~22.60%及水分利用效率8.28%~55.39%( P <0.05);产量与块茎形成期的单株薯干重正相关( r =0.744),覆盖处理在块茎形成期较CK提高单株薯干重118.0%~720.0%( P <0.05),以T4最高;覆盖处理对马铃薯水热特征有显著影响( P <0.05),T1、T2的降温效应显著小于T3,T3的蓄水保墒效应与T4差异不显著,但显著大于T1、T2及CK。可见,在本试验条件下,秸秆带状覆盖种植带旋耕的产量高于旧膜直播、略低于新覆膜,但蓄水保墒效应与新覆膜相近,同时秸秆带状覆盖种植带旋耕较其余覆盖处理具有较明显的降温增墒效应,有利于促进马铃薯块茎的形成及膨大。
文摘冻融循环破坏了土的结构,降低了土的力学性能。完成了石灰固化土与纤维加筋固化土的冻融试验、无侧限抗压试验、扫描电镜(scanning election microscopy,简称SEM)观察与核磁共振(nuclear magnetic resonance,简称NMR)测试,探讨冻融循环对土的强度与微结构的破坏作用,以微结构指标评价土的抗压强度变化。结果表明:石灰固化土与纤维加筋固化土的抗压强度均随冻融次数的增加而降低,土的冻融破坏过程经历了降幅较大、降幅较小、降幅平缓与强度稳定4个阶段;含水率越大,冻融次数越多,纤维对土的增强效果越明显;掺加纤维延缓了微裂隙的形成与发展,降低了裂隙的贯通率;随着冻融次数的增加,孔隙率与孔径均增大,冻胀使得部分小孔隙联通为中孔隙和大孔隙。纤维对土的空间约束作用与筋土摩擦作用使得土的孔隙率与孔隙分布特征变化较小,纤维加筋固化土的强度与抗冻融性能优于固化土。
基金the China Agricultural Research System of MOF and MARA(CARS-03-84)the National Natural Science Foundation of China(31960830)the State Key Laboratory of Aridland Crop Science,Gansu Agricultural University,China(GSCS-2019-Z05).
文摘An improved straw mulching model may be a sustainable agricultural production technology due to its improvements in soil water and the fertilizer environment by the recycling of waste straw resources.A four-year field experiment was conducted in a randomized block design on the Loess Plateau of northwestern China in 2015–2019,which aimed to study the effects of straw strip mulching(SSM)and conventional flat planting without mulching(CK)on soil water storage,water consumption characteristics,water use efficiency,precipitation use efficiency,winter wheat growth,economic benefits,and nutrient benefits.The results obtained for the four years showed that the SSM treatment improved soil water storage in the 0–180 cm soil layer over the whole growth period,which was especially obvious in the 0–60 cm soil layer at the jointing and blooming stages.Compared with CK,SSM increased the contribution rate of precipitation to total evapotranspiration and increased it quite significantly by 20.4 percentage points in the earlier growth period.SSM significantly reduced soil water storage consumption in the 0–180 cm soil layer and ultimately reduced evapotranspiration by 11.2 mm during the whole period.In the 0–180 cm soil layer,SSM decreased evapotranspiration by 33.1 mm from the sowing to the jointing stages,but increased it by 19.5 mm from the jointing to the blooming stages.In addition,SSM improved the water use efficiency of grain yield by 21.6%and improved the precipitation use efficiency of grain yield by 18.6%,and it ultimately increased grain yield by 16.5%through improving spike number by 9.5%and kernel number per spike by 8.9%.SSM improved the water use efficiency of biomass yield by 13.5%and the precipitation use efficiency of biomass yield by 9.9%,and it ultimately increased biomass yield by 8.7%and plant height by 6.5%.Furthermore,SSM increased net income by 413 CNY ha–1 and the total amount of straw returned to the field after harvest by 8876–9619 kg ha–1.After returning straw to the field,SSM significantly increased the soil nutrient contents,which could significantly reduce the burden of fertilization by farmers after a few years.Therefore,straw strip mulching technology could probably be a sustainable and potentially useful practice,which could save water and increase efficiency in rainfed winter wheat production.