Decision Support Tool(DST)enables farmers to make site-specific crop management decisions;however,comprehensive calibration can be both costly and time-consuming.This study assessed the production and economic benefit...Decision Support Tool(DST)enables farmers to make site-specific crop management decisions;however,comprehensive calibration can be both costly and time-consuming.This study assessed the production and economic benefits of two calibrations of the Nutrient Expert(NE)tool for rice in Sri Lanka’s Alfisols:the basic calibration(Nutrient Expert Sri Lanka 1,NESL1)and the comprehensive calibration(Nutrient Expert Sri Lanka 2,NESL2).NESL1 was developed by adapting the South Indian version of NE to local conditions,while NESL2 was an updated version,using three years of data from 71 farmer fields.展开更多
From 2017 to 2018,the effects of winter planting of milk vetch on yield and partial productivity of nitrogen fertilizer of machine-transplanted double-cropping rice under straw returning were studied in Ningxiang city...From 2017 to 2018,the effects of winter planting of milk vetch on yield and partial productivity of nitrogen fertilizer of machine-transplanted double-cropping rice under straw returning were studied in Ningxiang city,Hunan Province.The results showed that the dry matter accumulation,effective panicle,yield and partial productivity of nitrogen fertilizer in the stem,leaf,panicle and aboveground parts of early and late rice treated with winter planting milk vetch and straw returning were signi ficantly higher than those treated with straw returning only.Among them,the effective panicles of early and late rice increased by 2.58%,3.18%(2017)and 5.22%,6.32%(2018),respectively.Yield increased by 11.85%,10.07%(2017)and 12.42%,10.92%(2018),annual partial productivity of nitrogen fertilizer increased by 10.90%(2017)and 11.66%(2018),respectively.In conclusion,winter planting milk vetch under straw returning is beneficial to increase dry matter accumulation,rice yield and partial productivity of nitrogen fertilizer in mechanized double cropping rice.展开更多
Consider a sequence of i.i.d.positive random variables.An universal result in almost sure limit theorem for products of sums of partial sums is established.We will show that the almost sure limit theorem holds under a...Consider a sequence of i.i.d.positive random variables.An universal result in almost sure limit theorem for products of sums of partial sums is established.We will show that the almost sure limit theorem holds under a fairly general condition on the weight dk= k-1 exp（lnβk）,0≤β〈1.And in a sense,our results have reached the optimal form.展开更多
For each real number x∈(0,1),let[a_(1)(x),a_(2)(x),…,a_n(x),…]denote its continued fraction expansion.We study the convergence exponent defined byτ(x)=inf{s≥0:∞∑n=1(a_(n)(x)a_(n+1)(x))^(-s)<∞},which reflect...For each real number x∈(0,1),let[a_(1)(x),a_(2)(x),…,a_n(x),…]denote its continued fraction expansion.We study the convergence exponent defined byτ(x)=inf{s≥0:∞∑n=1(a_(n)(x)a_(n+1)(x))^(-s)<∞},which reflects the growth rate of the product of two consecutive partial quotients.As a main result,the Hausdorff dimensions of the level sets ofτ(x)are determined.展开更多
The tentative tariff rate for partial import and export products was adjusted since November 1^(st) of 2006.Total 58 imported commodities will be imposed lower tentative
Subsoil acidity restricts root growth and reduces crop yields in many parts of the world. More than half of the fertilizer nitrogen(N) applied in crop production is currently lost to the environment. This study aimed ...Subsoil acidity restricts root growth and reduces crop yields in many parts of the world. More than half of the fertilizer nitrogen(N) applied in crop production is currently lost to the environment. This study aimed to investigate the effect of gypsum application on the efficiency of N fertilizer in no-till corn(Zea mays L.) production in southern Brazil. A field experiment examined the effects of surface-applied gypsum(0, 5, 10, and 15 Mg ha^(-1)) and top-dressed ammonium nitrate(NH_4NO_3)(60, 120, and 180 kg N ha^(-1)) on corn root length, N uptake, and grain yield. A greenhouse experiment was conducted using undisturbed soil columns collected from the field experiment site to evaluate NO_3-N leaching, N uptake, and root length with surface-applied gypsum(0 and 10 Mg ha^(-1)) and top-dressed NH_4NO_3(0 and 180 kg N ha^(-1)). Amelioration of subsoil acidity due to gypsum application increased corn root growth,N uptake, grain yield, and N use efficiency. Applying gypsum to the soil surface increased corn grain yield by 19%–38% and partial factor productivity of N(PFPN) by 27%–38%, depending on the N application rate. Results of the undisturbed soil column greenhouse experiment showed that improvement of N use efficiency by gypsum application was due to the higher N uptake from NO_3-N in the subsoil as a result of increased corn root length. Our results suggest that ameliorating subsoil acidity with gypsum in a no-till corn system could increase N use efficiency, improve grain yield, and reduce environmental risks due to NO_3-N leaching.展开更多
基金supported by the National Research Council of Sri Lanka(Grant No.NRC TO 16-07).
文摘Decision Support Tool(DST)enables farmers to make site-specific crop management decisions;however,comprehensive calibration can be both costly and time-consuming.This study assessed the production and economic benefits of two calibrations of the Nutrient Expert(NE)tool for rice in Sri Lanka’s Alfisols:the basic calibration(Nutrient Expert Sri Lanka 1,NESL1)and the comprehensive calibration(Nutrient Expert Sri Lanka 2,NESL2).NESL1 was developed by adapting the South Indian version of NE to local conditions,while NESL2 was an updated version,using three years of data from 71 farmer fields.
文摘From 2017 to 2018,the effects of winter planting of milk vetch on yield and partial productivity of nitrogen fertilizer of machine-transplanted double-cropping rice under straw returning were studied in Ningxiang city,Hunan Province.The results showed that the dry matter accumulation,effective panicle,yield and partial productivity of nitrogen fertilizer in the stem,leaf,panicle and aboveground parts of early and late rice treated with winter planting milk vetch and straw returning were signi ficantly higher than those treated with straw returning only.Among them,the effective panicles of early and late rice increased by 2.58%,3.18%(2017)and 5.22%,6.32%(2018),respectively.Yield increased by 11.85%,10.07%(2017)and 12.42%,10.92%(2018),annual partial productivity of nitrogen fertilizer increased by 10.90%(2017)and 11.66%(2018),respectively.In conclusion,winter planting milk vetch under straw returning is beneficial to increase dry matter accumulation,rice yield and partial productivity of nitrogen fertilizer in mechanized double cropping rice.
基金Supported by the National Natural Science Foundation of China(11061012)Project Supported by Program to Sponsor Teams for Innovation in the Construction of Talent Highlands in Guangxi Institutions of Higher Learning([2011]47)the Guangxi Natural Science Foundation of China(2012GXNSFAA053010)
文摘Consider a sequence of i.i.d.positive random variables.An universal result in almost sure limit theorem for products of sums of partial sums is established.We will show that the almost sure limit theorem holds under a fairly general condition on the weight dk= k-1 exp（lnβk）,0≤β〈1.And in a sense,our results have reached the optimal form.
基金supported by the Scientific Research Fund of Hunan Provincial Education Department(21B0070)the Natural Science Foundation of Jiangsu Province(BK20231452)+1 种基金the Fundamental Research Funds for the Central Universities(30922010809)the National Natural Science Foundation of China(11801591,11971195,12071171,12171107,12201207,12371072)。
文摘For each real number x∈(0,1),let[a_(1)(x),a_(2)(x),…,a_n(x),…]denote its continued fraction expansion.We study the convergence exponent defined byτ(x)=inf{s≥0:∞∑n=1(a_(n)(x)a_(n+1)(x))^(-s)<∞},which reflects the growth rate of the product of two consecutive partial quotients.As a main result,the Hausdorff dimensions of the level sets ofτ(x)are determined.
文摘The tentative tariff rate for partial import and export products was adjusted since November 1^(st) of 2006.Total 58 imported commodities will be imposed lower tentative
基金supported by CNPq(Conselho Nacional de Desenvolvimento Científico e Tecnológico),BrazilCAPES(Coordenacao de Aperfeicoamento de Pessoal de Nível Superior),Brazil
文摘Subsoil acidity restricts root growth and reduces crop yields in many parts of the world. More than half of the fertilizer nitrogen(N) applied in crop production is currently lost to the environment. This study aimed to investigate the effect of gypsum application on the efficiency of N fertilizer in no-till corn(Zea mays L.) production in southern Brazil. A field experiment examined the effects of surface-applied gypsum(0, 5, 10, and 15 Mg ha^(-1)) and top-dressed ammonium nitrate(NH_4NO_3)(60, 120, and 180 kg N ha^(-1)) on corn root length, N uptake, and grain yield. A greenhouse experiment was conducted using undisturbed soil columns collected from the field experiment site to evaluate NO_3-N leaching, N uptake, and root length with surface-applied gypsum(0 and 10 Mg ha^(-1)) and top-dressed NH_4NO_3(0 and 180 kg N ha^(-1)). Amelioration of subsoil acidity due to gypsum application increased corn root growth,N uptake, grain yield, and N use efficiency. Applying gypsum to the soil surface increased corn grain yield by 19%–38% and partial factor productivity of N(PFPN) by 27%–38%, depending on the N application rate. Results of the undisturbed soil column greenhouse experiment showed that improvement of N use efficiency by gypsum application was due to the higher N uptake from NO_3-N in the subsoil as a result of increased corn root length. Our results suggest that ameliorating subsoil acidity with gypsum in a no-till corn system could increase N use efficiency, improve grain yield, and reduce environmental risks due to NO_3-N leaching.
