Straw return is an important management tool for tackling and promoting soil nutrient conservation and improving crop yield in Huang-Huai-Hai Plain, China. Although the incorporation of maize straw with deep plowing a...Straw return is an important management tool for tackling and promoting soil nutrient conservation and improving crop yield in Huang-Huai-Hai Plain, China. Although the incorporation of maize straw with deep plowing and rotary tillage practices are widespread in the region, only few studies have focused on rotation tillage. To determine the effects of maize straw return on the nitrogen （N） efficiency and grain yield of winter wheat （Triticum aestivum L.）, we conducted experiments in this region for 3 years. Five treatments were tested： （i） rotary tillage without straw return （RT）; （ii） deep plowing tillage without straw return （DT）; （iii） rotary tillage with total straw return （RS）; （iv） deep plowing tillage with total straw return （DS）; （v） rotary tillage of 2 years and deep plowing tillage in the 3rd year with total straw return （TS）. Treatments with straw return increased kernels no. ear-1, thousand-kernel weight （TKW）, grain yields, ratio of dry matter accumulation post-anthesis, and nitrogen （N） efficiency whereas reduced the ears no. ha-1 in the 2011-2012 and 2012-2013 growing seasons. Compared with the rotary tillage, deep plowing tillage significantly increased the grain yield, yield components, total dry matter accumulation, and N efficiency in 2013-2014. RS had significantly higher straw N distribution, soil inorganic nitrogen content, and soil enzymes activities in the 0-10 cm soil layer compared with the DS and TS. However, significantly lower values were ob- served in the 10-20 and 20-30 cm soil layers. TS obtained approximately equal grain yield as DS, and it also reduced the resource costs. Therefore, we conclude that TS is the most economical method for increasing grain yield and N efficiency of winter wheat in Huang-Huai-Hai Plain.展开更多
[Objectives]This study was conducted to improve the quality of straw returning to the field,enhance wheat disease resistance and ensure high and stable yield of wheat.[Methods]The effects of four returning modes on wh...[Objectives]This study was conducted to improve the quality of straw returning to the field,enhance wheat disease resistance and ensure high and stable yield of wheat.[Methods]The effects of four returning modes on wheat stem rot and yield were studied by observation and experiments.[Results]The incidence rate and disease index of stem rot and white head rate of wheat were significantly reduced and the yield was significantly increased by adopting the method of straw returning to the field with the separation of"returning and seeding".The incidence rate and disease index of stem rot and white head rate of wheat were higher than those of the CK and the yield was significantly reduced when adopting the straw returning method of direct sowing.Treatment T_(1)(after maize was harvested,fertilizers,a nutrient-loaded microbial agent and a soil conditioner were evenly spread on the surface of straw,which was then returned to the field using a straw returning machine twice,and then ploughing,soil preparation and wheat sowing were carried out)showed an incidence rate of wheat crown rot 54.8%lower than that of the CK and a white head rate 87.5%lower than that of the CK,and the yield was 2305 kg/hm^(2) higher than that of the CK.[Conclusions]Straw returning can increase soil organic matter content,reduce soil bulk density,enhance soil respiration,and improve wheat disease resistance and yield.展开更多
[Objectives]To alleviate the influence of meteorological conditions on soil environment(temperature and water content)and maintain high and stable grain yield.[Methods]Taking Sunzhen Experimental Station of Weinan Aca...[Objectives]To alleviate the influence of meteorological conditions on soil environment(temperature and water content)and maintain high and stable grain yield.[Methods]Taking Sunzhen Experimental Station of Weinan Academy of Agricultural Sciences as the experimental base,the effects of returning double-crop wheat and corn straw to field(Twm),returning single-crop corn straw to field(Tm),returning single-crop wheat straw to field(Tw)on soil temperature,water content,straw decomposition rate and nutrient release,soil organic matter and bulk density were studied systematically.[Results]Twm treatment could effectively alleviate the effects of meteorological conditions on soil temperature and water content.The decomposition rate of straw treated with Twm was 4.7%higher than that of Tm treatment,3.8%higher than that of Tw treatment,10.5%higher than that of Tm treatment,and the decomposition rate of straw showed a trend of"first fast,then slow and then fast".The release of nitrogen from straw was basically similar to that of straw decay,and the release of potassium and phosphorus increased at first and then remained basically unchanged.The release rate of potassium was the highest,followed by phosphorus and nitrogen.The content of soil organic matter in Twm treatment increased by 11.67%annually,an annual average of 0.998 g/kg.The soil bulk density of Twm treatment decreased by 0.058 g/cm^(3) annually,an annual average of 4.29%.The fundamental reason is that Twm treatment provides conditions(temperature,water content,nutrition)for microbial growth,reproduction,enzyme production and biochemical reaction,and increases the exchange capacity of soil and external water,heat,gas and fertilizer.[Conclusions]It is expected is to help people change their understanding of returning straw to field from"quick harvest"to"fertilizer transformation".展开更多
A model for both stochastic jumps and volatility for equity returns in the area of option pricing is the stochastic volatility process with jumps (SVPJ). A major advantage of this model lies in the area of mean revers...A model for both stochastic jumps and volatility for equity returns in the area of option pricing is the stochastic volatility process with jumps (SVPJ). A major advantage of this model lies in the area of mean reversion and volatility clustering between returns and volatility with uphill movements in price asserts. Thus, in this article, we propose to solve the SVPJ model numerically through a discretized variational iteration method (DVIM) to obtain sample paths for the state variable and variance process at various timesteps and replications in order to estimate the expected jump times at various iterates resulting from executing the DVIM as n increases. These jumps help in estimating the degree of randomness in the financial market. It was observed that the average computed expected jump times for the state variable and variance process is moderated by the parameters (variance process through mean reversion), Θ (long-run mean of the variance process), σ (volatility variance process) and λ (constant intensity of the Poisson process) at each iterate. For instance, when = 0.0, Θ = 0.0, σ = 0.0 and λ = 1.0, the state variable cluttered maximally compared to the variance process with less volatility cluttering with an average computed expected jump times of 52.40607869 as n increases in the DVIM scheme. Similarly, when = 3.99, Θ = 0.014, σ = 0.27 and λ = 0.11, the stochastic jumps for the state variable are less cluttered compared to the variance process with maximum volatility cluttering as n increases in the DVIM scheme. In terms of option pricing, the value 52.40607869 suggest a better bargain compared to the value 20.40344029 due to the fact that it yields less volatility rate. MAPLE 18 software was used for all computations in this research.展开更多
小麦-玉米连作区的秸秆还田已经成为大多数小麦-玉米连作区的重要生产模式,由于秸秆不断还田和全球气候条件的改变,由镰刀菌Fusarium spp.引起的小麦赤霉病(Fusarium head blight)已经成为小麦生产中的重要威胁之一。本研究通过在河北...小麦-玉米连作区的秸秆还田已经成为大多数小麦-玉米连作区的重要生产模式,由于秸秆不断还田和全球气候条件的改变,由镰刀菌Fusarium spp.引起的小麦赤霉病(Fusarium head blight)已经成为小麦生产中的重要威胁之一。本研究通过在河北省小麦主产区石家庄北营、邢台塔底、廊坊北黄垡、邢台白木四地比较深翻(30 cm)与旋耕(15 cm)2种耕作方式对小麦生长和赤霉病发生的影响,旨在寻找高产、绿色、安全的防治小麦赤霉病途径。通过研究发现,深翻处理可以有效减少地表秸秆量,深翻地块的地表秸秆量较旋耕的减少53.8%~89.0%;深翻促进了小麦的生长,提高小麦产量6.97%~11.96%;深翻处理田块中捕获的赤霉病菌的有性孢子数量少于旋耕处理,赤霉病的发病率降低。在测试的北营、塔底、北黄垡、白木试验地中深翻对赤霉病的控制效果分别达到40.56%、43.62%、60.00%和50.26%。深翻措施能有效提高小麦的生长势和产量,减轻小麦赤霉病的发生程度,是一种绿色、安全、利于小麦高产的方法。展开更多
基金supported by the National Key Research and Development Program of China(2016YFD0300400)the National Basic Research Program of China(973 Program,2015CB150404)+4 种基金the Special Fund for Agroscientific Research in Public Interest of China(201203100)the National Key Technologies R&D Program of China during the 12th Five-year Plan period(2012BAD04B05)the Project of Shandong Province Higher Educational Science and Technology,China(J14LF12)the Shandong Province Mount Tai Industrial Talents Program,Chinathe Shandong Province Key Agricultural Project for Application Technology Innovation,China
文摘Straw return is an important management tool for tackling and promoting soil nutrient conservation and improving crop yield in Huang-Huai-Hai Plain, China. Although the incorporation of maize straw with deep plowing and rotary tillage practices are widespread in the region, only few studies have focused on rotation tillage. To determine the effects of maize straw return on the nitrogen （N） efficiency and grain yield of winter wheat （Triticum aestivum L.）, we conducted experiments in this region for 3 years. Five treatments were tested： （i） rotary tillage without straw return （RT）; （ii） deep plowing tillage without straw return （DT）; （iii） rotary tillage with total straw return （RS）; （iv） deep plowing tillage with total straw return （DS）; （v） rotary tillage of 2 years and deep plowing tillage in the 3rd year with total straw return （TS）. Treatments with straw return increased kernels no. ear-1, thousand-kernel weight （TKW）, grain yields, ratio of dry matter accumulation post-anthesis, and nitrogen （N） efficiency whereas reduced the ears no. ha-1 in the 2011-2012 and 2012-2013 growing seasons. Compared with the rotary tillage, deep plowing tillage significantly increased the grain yield, yield components, total dry matter accumulation, and N efficiency in 2013-2014. RS had significantly higher straw N distribution, soil inorganic nitrogen content, and soil enzymes activities in the 0-10 cm soil layer compared with the DS and TS. However, significantly lower values were ob- served in the 10-20 and 20-30 cm soil layers. TS obtained approximately equal grain yield as DS, and it also reduced the resource costs. Therefore, we conclude that TS is the most economical method for increasing grain yield and N efficiency of winter wheat in Huang-Huai-Hai Plain.
基金Supported by Shaanxi Provincial Innovation Capability Support Program(2019XY-03)Shaanxi Provincial Key R&D Program(2019ZDLNY01-05-02)+3 种基金Key R&D Project of Guangxi Zhuang Autonomous Region(GK AB19259016)Scientific and Technological Innovation Program of Shaanxi Academy of Forestry(SXLK2020-0218)Xi’an Science and Technology Program(20193051YF039N039)Xianyang Key R&D Program(2021DYF-GY-0008)。
文摘[Objectives]This study was conducted to improve the quality of straw returning to the field,enhance wheat disease resistance and ensure high and stable yield of wheat.[Methods]The effects of four returning modes on wheat stem rot and yield were studied by observation and experiments.[Results]The incidence rate and disease index of stem rot and white head rate of wheat were significantly reduced and the yield was significantly increased by adopting the method of straw returning to the field with the separation of"returning and seeding".The incidence rate and disease index of stem rot and white head rate of wheat were higher than those of the CK and the yield was significantly reduced when adopting the straw returning method of direct sowing.Treatment T_(1)(after maize was harvested,fertilizers,a nutrient-loaded microbial agent and a soil conditioner were evenly spread on the surface of straw,which was then returned to the field using a straw returning machine twice,and then ploughing,soil preparation and wheat sowing were carried out)showed an incidence rate of wheat crown rot 54.8%lower than that of the CK and a white head rate 87.5%lower than that of the CK,and the yield was 2305 kg/hm^(2) higher than that of the CK.[Conclusions]Straw returning can increase soil organic matter content,reduce soil bulk density,enhance soil respiration,and improve wheat disease resistance and yield.
基金Shaanxi Provincial Innovation Capability Support Program(2019XY-03)Key R&D Program of Shaanxi Province(2019ZDLN01-05-02)+2 种基金Guangxi Key R&D Program(GuiKe AB19259016)Project of Shaanxi Academy of Forestry Sciences(SXLK2020-0218)Xi'an Science and Technology Plan Project(20193051YF039NS039,20NYYF0026).
文摘[Objectives]To alleviate the influence of meteorological conditions on soil environment(temperature and water content)and maintain high and stable grain yield.[Methods]Taking Sunzhen Experimental Station of Weinan Academy of Agricultural Sciences as the experimental base,the effects of returning double-crop wheat and corn straw to field(Twm),returning single-crop corn straw to field(Tm),returning single-crop wheat straw to field(Tw)on soil temperature,water content,straw decomposition rate and nutrient release,soil organic matter and bulk density were studied systematically.[Results]Twm treatment could effectively alleviate the effects of meteorological conditions on soil temperature and water content.The decomposition rate of straw treated with Twm was 4.7%higher than that of Tm treatment,3.8%higher than that of Tw treatment,10.5%higher than that of Tm treatment,and the decomposition rate of straw showed a trend of"first fast,then slow and then fast".The release of nitrogen from straw was basically similar to that of straw decay,and the release of potassium and phosphorus increased at first and then remained basically unchanged.The release rate of potassium was the highest,followed by phosphorus and nitrogen.The content of soil organic matter in Twm treatment increased by 11.67%annually,an annual average of 0.998 g/kg.The soil bulk density of Twm treatment decreased by 0.058 g/cm^(3) annually,an annual average of 4.29%.The fundamental reason is that Twm treatment provides conditions(temperature,water content,nutrition)for microbial growth,reproduction,enzyme production and biochemical reaction,and increases the exchange capacity of soil and external water,heat,gas and fertilizer.[Conclusions]It is expected is to help people change their understanding of returning straw to field from"quick harvest"to"fertilizer transformation".
文摘A model for both stochastic jumps and volatility for equity returns in the area of option pricing is the stochastic volatility process with jumps (SVPJ). A major advantage of this model lies in the area of mean reversion and volatility clustering between returns and volatility with uphill movements in price asserts. Thus, in this article, we propose to solve the SVPJ model numerically through a discretized variational iteration method (DVIM) to obtain sample paths for the state variable and variance process at various timesteps and replications in order to estimate the expected jump times at various iterates resulting from executing the DVIM as n increases. These jumps help in estimating the degree of randomness in the financial market. It was observed that the average computed expected jump times for the state variable and variance process is moderated by the parameters (variance process through mean reversion), Θ (long-run mean of the variance process), σ (volatility variance process) and λ (constant intensity of the Poisson process) at each iterate. For instance, when = 0.0, Θ = 0.0, σ = 0.0 and λ = 1.0, the state variable cluttered maximally compared to the variance process with less volatility cluttering with an average computed expected jump times of 52.40607869 as n increases in the DVIM scheme. Similarly, when = 3.99, Θ = 0.014, σ = 0.27 and λ = 0.11, the stochastic jumps for the state variable are less cluttered compared to the variance process with maximum volatility cluttering as n increases in the DVIM scheme. In terms of option pricing, the value 52.40607869 suggest a better bargain compared to the value 20.40344029 due to the fact that it yields less volatility rate. MAPLE 18 software was used for all computations in this research.
