Tillage represents an important practice that is used to dynamically regulate soil properties,and affects the grain production process and resource use efficiency of crops.The objectives of this 3-year field study car...Tillage represents an important practice that is used to dynamically regulate soil properties,and affects the grain production process and resource use efficiency of crops.The objectives of this 3-year field study carried out in the Huang-Huai-Hai(HHH) Plain of China were to compare the effects of a new deep vertical rotary tillage (DVRT) with the conventional shallow rotary tillage (CT) on soil properties,winter wheat (Triticum aestivum L.) grain yield and water and nitrogen use efficiency at different productivity levels,and to identify a comprehensive management that optimizes both grain yield and resource use efficiency in the HHH Plain.A split-plot design was adopted in field experiments in the winter wheat growing seasons of 2016–2017 (S1),2017–2018 (S2) and 2018–2019 (S3),with DVRT (conducted once in June 2016) and CT performed in the main plots.Subplots were treated with one of four targeted productivity level treatments (SH,the super high productivity level;HH,the high productivity and high efficiency productivity level;FP,the farmer productivity level;ISP,the inherent soil productivity level).The results showed that the soil bulk density was reduced and the soil water content at the anthesis stage was increased in all three years,which were due to the significant effects of DVRT.Compared with CT,grain yields,partial factor productivity of nitrogen (PFP_(N)),and water use efficiency (WUE) under DVRT were increased by 22.0,14.5 and 19.0%.Path analysis and direct correlation decomposition uncovered that grain yield variation of winter wheat was mostly contributed by the spike numbers per area under different tillage modes.General line model analysis revealed that tillage mode played a significant role on grain yield,PFP_(N) and WUE not only as a single factor,but also along with other factors(year and productivity level) in interaction manners.In addition,PFP_(N) and WUE were the highest in HH under DVRT in all three growth seasons.These results provided a theoretical basis and technical support for coordinating the high yield with high resource use efficiency of winter wheat in the resource-restricted region in the HHH Plain of China.展开更多
Inappropriate tillage practices and nitrogen(N) management have become seriously limitations for maize(Zea mays L.) yield and N use efficiency(NUE) in the North China Plain(NCP). In the current study, we examined the ...Inappropriate tillage practices and nitrogen(N) management have become seriously limitations for maize(Zea mays L.) yield and N use efficiency(NUE) in the North China Plain(NCP). In the current study, we examined the effects of strip deep rotary tillage(ST) combined with controlled-release(CR) urea on maize yield and NUE, and determined the physiological factors involved in yield formation and N accumulation during a 2-year field experiment. Compared with conventional rotary tillage(RT) and no-tillage(NT), ST increased the soil water content and soil mineral N content(Nmin) in the 20–40 cm soil layer due to reduction by 10.5 and 13.7% in the soil bulk density in the 0–40 cm soil layer, respectively. Compared with the values obtained by common urea(CU) fertilization, CR increased the Nmin in the 0–40 cm soil layers by 12.4 and 10.3% at the silking and maturity stages, respectively. As a result, root length and total N accumulation were enhanced under ST and CR urea, which promoted greater leaf area and dry matter(particularly at post-silking), eventually increasing the1 000-kernel weight of maize. Thus, ST increased the maize yield by 8.3 and 11.0% compared with RT and NT, respectively, whereas CR urea increased maize yield by 8.9% above the values obtained under CU. Because of greater grain yield and N accumulation, ST combined with CR urea improved the NUE substantially. These results show that ST coupled with CR urea is an effective practice to further increase maize yield and NUE by improving soil properties and N supply, so it should be considered for sustainable maize production in the NCP(and other similar areas worldwide).展开更多
针对秸秆还田机具关键部件设计优化过程中秸秆-刀具互作关系分析缺乏准确秸秆离散元模型的问题,本文以水稻秸秆为研究对象,基于Hertz-Mindlin with Bonding接触模型,采用颗粒替换方式构建水稻秸秆离散元柔性模型,开展了离散元接触模型...针对秸秆还田机具关键部件设计优化过程中秸秆-刀具互作关系分析缺乏准确秸秆离散元模型的问题,本文以水稻秸秆为研究对象,基于Hertz-Mindlin with Bonding接触模型,采用颗粒替换方式构建水稻秸秆离散元柔性模型,开展了离散元接触模型参数标定与多工况试验验证。通过物理试验测定了水稻秸秆摩擦因数,以秸秆弯曲试验测得最大载荷作为参数标定试验指标,通过Plackett-Burman试验和最陡爬坡试验筛选柔性模型显著性因素及其最优值范围,并由Central-Composite试验确定了显著性因素的最优值组合为:法向接触刚度3.040×10^(10)N/m^(3)、切向接触刚度2.296×10^(10)N/m^(3),该标定参数值所得最大载荷仿真值与实测值相对误差为1.82%,表明标定参数有效。通过刀具弯曲试验和旋耕刀旋转切割试验验证上述标定方法在不同工况下的有效性,刀具弯曲试验中仿真所得最大载荷与实测最大载荷相对误差不大于4.55%,旋耕刀旋转切割试验中仿真所得最大扭矩与实测最大扭矩相对误差不大于7.95%,研究结果表明,以弯曲试验参数标定法构建的水稻秸秆柔性模型在秸秆弯曲试验和旋耕刀旋转切割过程仿真中均准确有效,适用于旋耕作业条件下仿真分析,可为秸秆还田机具旋耕部件优化设计提供参考。展开更多
基金supported and funded by the National Key Research and Development Program of China(2016YFD0300105,2017YFD03002 and 2016YFD0300106)the Key Research and Development Program of Hebei Province,China(20326403D)。
文摘Tillage represents an important practice that is used to dynamically regulate soil properties,and affects the grain production process and resource use efficiency of crops.The objectives of this 3-year field study carried out in the Huang-Huai-Hai(HHH) Plain of China were to compare the effects of a new deep vertical rotary tillage (DVRT) with the conventional shallow rotary tillage (CT) on soil properties,winter wheat (Triticum aestivum L.) grain yield and water and nitrogen use efficiency at different productivity levels,and to identify a comprehensive management that optimizes both grain yield and resource use efficiency in the HHH Plain.A split-plot design was adopted in field experiments in the winter wheat growing seasons of 2016–2017 (S1),2017–2018 (S2) and 2018–2019 (S3),with DVRT (conducted once in June 2016) and CT performed in the main plots.Subplots were treated with one of four targeted productivity level treatments (SH,the super high productivity level;HH,the high productivity and high efficiency productivity level;FP,the farmer productivity level;ISP,the inherent soil productivity level).The results showed that the soil bulk density was reduced and the soil water content at the anthesis stage was increased in all three years,which were due to the significant effects of DVRT.Compared with CT,grain yields,partial factor productivity of nitrogen (PFP_(N)),and water use efficiency (WUE) under DVRT were increased by 22.0,14.5 and 19.0%.Path analysis and direct correlation decomposition uncovered that grain yield variation of winter wheat was mostly contributed by the spike numbers per area under different tillage modes.General line model analysis revealed that tillage mode played a significant role on grain yield,PFP_(N) and WUE not only as a single factor,but also along with other factors(year and productivity level) in interaction manners.In addition,PFP_(N) and WUE were the highest in HH under DVRT in all three growth seasons.These results provided a theoretical basis and technical support for coordinating the high yield with high resource use efficiency of winter wheat in the resource-restricted region in the HHH Plain of China.
基金funded by the National Natural Science Foundation of China(32071957)the Key National Research and Development Program of China(2018YFD0300504)+1 种基金the Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(2060302-2)the China Agriculture Research System of MOF and MARA(CARS-02)。
文摘Inappropriate tillage practices and nitrogen(N) management have become seriously limitations for maize(Zea mays L.) yield and N use efficiency(NUE) in the North China Plain(NCP). In the current study, we examined the effects of strip deep rotary tillage(ST) combined with controlled-release(CR) urea on maize yield and NUE, and determined the physiological factors involved in yield formation and N accumulation during a 2-year field experiment. Compared with conventional rotary tillage(RT) and no-tillage(NT), ST increased the soil water content and soil mineral N content(Nmin) in the 20–40 cm soil layer due to reduction by 10.5 and 13.7% in the soil bulk density in the 0–40 cm soil layer, respectively. Compared with the values obtained by common urea(CU) fertilization, CR increased the Nmin in the 0–40 cm soil layers by 12.4 and 10.3% at the silking and maturity stages, respectively. As a result, root length and total N accumulation were enhanced under ST and CR urea, which promoted greater leaf area and dry matter(particularly at post-silking), eventually increasing the1 000-kernel weight of maize. Thus, ST increased the maize yield by 8.3 and 11.0% compared with RT and NT, respectively, whereas CR urea increased maize yield by 8.9% above the values obtained under CU. Because of greater grain yield and N accumulation, ST combined with CR urea improved the NUE substantially. These results show that ST coupled with CR urea is an effective practice to further increase maize yield and NUE by improving soil properties and N supply, so it should be considered for sustainable maize production in the NCP(and other similar areas worldwide).
文摘针对秸秆还田机具关键部件设计优化过程中秸秆-刀具互作关系分析缺乏准确秸秆离散元模型的问题,本文以水稻秸秆为研究对象,基于Hertz-Mindlin with Bonding接触模型,采用颗粒替换方式构建水稻秸秆离散元柔性模型,开展了离散元接触模型参数标定与多工况试验验证。通过物理试验测定了水稻秸秆摩擦因数,以秸秆弯曲试验测得最大载荷作为参数标定试验指标,通过Plackett-Burman试验和最陡爬坡试验筛选柔性模型显著性因素及其最优值范围,并由Central-Composite试验确定了显著性因素的最优值组合为:法向接触刚度3.040×10^(10)N/m^(3)、切向接触刚度2.296×10^(10)N/m^(3),该标定参数值所得最大载荷仿真值与实测值相对误差为1.82%,表明标定参数有效。通过刀具弯曲试验和旋耕刀旋转切割试验验证上述标定方法在不同工况下的有效性,刀具弯曲试验中仿真所得最大载荷与实测最大载荷相对误差不大于4.55%,旋耕刀旋转切割试验中仿真所得最大扭矩与实测最大扭矩相对误差不大于7.95%,研究结果表明,以弯曲试验参数标定法构建的水稻秸秆柔性模型在秸秆弯曲试验和旋耕刀旋转切割过程仿真中均准确有效,适用于旋耕作业条件下仿真分析,可为秸秆还田机具旋耕部件优化设计提供参考。
