Reduced tillage provides ecological and economic benefits to arable land on the Loess Plateau of China, where soil erosion has long been a serious problem and soil water availability is largely restricted. However, hi...Reduced tillage provides ecological and economic benefits to arable land on the Loess Plateau of China, where soil erosion has long been a serious problem and soil water availability is largely restricted. However, high abundances of weeds in reduced tillage systems cause significant yield losses. In this study, we explored the effects of no-tillage and stubble retention on the number and density of weeds and weed seeds in a 12-year maize-winter wheat-common vetch rotation on the Loess Plateau. Four treatments including conventional tillage, no-tillage, conventional tillage＋stubble retention and no-tillage＋stubble retention were designed and applied. We found that no-tillage increased the number of weed species and weed density in most of the crops, while stubble retention decreased weed density in maize and tended to suppress weeds in both no-tillage treatments（no-tillage and no-tillage＋stubble retention）. No-tillage led to an increase in the number of weed species in the weed seedbank and tended to increase seed density during the spring growth of winter wheat, but it decreased seed density during post-vetch fallow. Stubble retention tended to reduce seed density during the spring growth of winter wheat and post-vetch fallow. We concluded that no-tillage can promote weeds in the experimental crop rotation, while stubble retention suppresses weeds in untilled fields. The combined effects of stubble retention and no-tillage on weed suppression varied among the three crops. Based on these results, we recommend stubble retention in untilled legume-crop rotations on the Loess Plateau to improve the control of weeds.展开更多
Under the conditions of straw returning operation,there are three major technical bottlenecks in the Phaeozem region of northeast China,namely low stubble breaking rate,poor tillage depth consistency,and high fuel con...Under the conditions of straw returning operation,there are three major technical bottlenecks in the Phaeozem region of northeast China,namely low stubble breaking rate,poor tillage depth consistency,and high fuel consumption.In this research,a bionic stubble-deep loosening combined tillage machine(BSD)was designed through bionic prototype analysis,coupled bionic analysis,coupled bionic design,theoretical analysis and application of intelligent control techniques.It consists of a bionic stubble breaking device and a bionic self-excited vibratory deep loosening device.Based on the unique biting pattern of locust mouthparts on maize rootstocks,the bionic stubble breaking device adopted a new multi-segment serrated bionic structure and a symmetrical rotational motion,which could significantly increase the stubble breaking rate(p<0.05)and reduce the resistance to stubble breaking operations(p<0.05).Based on the unique biology of the hare’s paws,toes and nails,the bionic self-excited vibration deep loosening device adopted a new series-parallel composite bionic elastic system and an intelligent tilling depth control system with a fuzzy algorithm,which significantly improved the tilling depth consistency(p<0.05).The operational performance of the BSD was verified at different operating speeds through comparative experiments and reveals the mechanism of its excellent performance through theoretical analysis.The final experiment results showed that,at the same operating speed,the BSD improved the stubble breaking rate by 9.62%and 10.67%,reduced the stubble breaking torque by 28 N·m and 33 N·m,reduced the tillage depth coefficient of variation by 12.73%and 13.48%,and reduced the specific fuel consumption by 36 g/km·h and 40 g/km·h compared to the two most common models.The operating performance of the three kinds of machines will decrease with the increase of operating speed,and the BSD has the least decrease.展开更多
基金supported by the National Natural Science Foundation of China(31572460)the Fundamental Research Funds for the Central Universities(lzujbky-2017-ot01)the National Key Research and Development Program of China(2016YFC0400302)
文摘Reduced tillage provides ecological and economic benefits to arable land on the Loess Plateau of China, where soil erosion has long been a serious problem and soil water availability is largely restricted. However, high abundances of weeds in reduced tillage systems cause significant yield losses. In this study, we explored the effects of no-tillage and stubble retention on the number and density of weeds and weed seeds in a 12-year maize-winter wheat-common vetch rotation on the Loess Plateau. Four treatments including conventional tillage, no-tillage, conventional tillage＋stubble retention and no-tillage＋stubble retention were designed and applied. We found that no-tillage increased the number of weed species and weed density in most of the crops, while stubble retention decreased weed density in maize and tended to suppress weeds in both no-tillage treatments（no-tillage and no-tillage＋stubble retention）. No-tillage led to an increase in the number of weed species in the weed seedbank and tended to increase seed density during the spring growth of winter wheat, but it decreased seed density during post-vetch fallow. Stubble retention tended to reduce seed density during the spring growth of winter wheat and post-vetch fallow. We concluded that no-tillage can promote weeds in the experimental crop rotation, while stubble retention suppresses weeds in untilled fields. The combined effects of stubble retention and no-tillage on weed suppression varied among the three crops. Based on these results, we recommend stubble retention in untilled legume-crop rotations on the Loess Plateau to improve the control of weeds.
基金The authors acknowledge that the research was financially supported by the National Key Research and Development Project of China(Grant No.2017YFD0700701)the Natural Science Foundation of China(Grant No.52075215)+1 种基金the Science and Technology Development Plan Project of Jilin Province(Grant No.20190301023NY,20190701055GH and 20200404008YY)China Postdoctoral Science Foundation(Grant No.2020M67085).
文摘Under the conditions of straw returning operation,there are three major technical bottlenecks in the Phaeozem region of northeast China,namely low stubble breaking rate,poor tillage depth consistency,and high fuel consumption.In this research,a bionic stubble-deep loosening combined tillage machine(BSD)was designed through bionic prototype analysis,coupled bionic analysis,coupled bionic design,theoretical analysis and application of intelligent control techniques.It consists of a bionic stubble breaking device and a bionic self-excited vibratory deep loosening device.Based on the unique biting pattern of locust mouthparts on maize rootstocks,the bionic stubble breaking device adopted a new multi-segment serrated bionic structure and a symmetrical rotational motion,which could significantly increase the stubble breaking rate(p<0.05)and reduce the resistance to stubble breaking operations(p<0.05).Based on the unique biology of the hare’s paws,toes and nails,the bionic self-excited vibration deep loosening device adopted a new series-parallel composite bionic elastic system and an intelligent tilling depth control system with a fuzzy algorithm,which significantly improved the tilling depth consistency(p<0.05).The operational performance of the BSD was verified at different operating speeds through comparative experiments and reveals the mechanism of its excellent performance through theoretical analysis.The final experiment results showed that,at the same operating speed,the BSD improved the stubble breaking rate by 9.62%and 10.67%,reduced the stubble breaking torque by 28 N·m and 33 N·m,reduced the tillage depth coefficient of variation by 12.73%and 13.48%,and reduced the specific fuel consumption by 36 g/km·h and 40 g/km·h compared to the two most common models.The operating performance of the three kinds of machines will decrease with the increase of operating speed,and the BSD has the least decrease.
