Climate change has a significant impact on agriculture.However,the impact investigation is currently limited to the analysis of meteorological data,and there is a dearth of long-term monitoring of crop phenology and s...Climate change has a significant impact on agriculture.However,the impact investigation is currently limited to the analysis of meteorological data,and there is a dearth of long-term monitoring of crop phenology and soil moisture associated with climate change.In this study,temperature and precipitation(1957-2020)were recorded,crop growth(1981-2019)data were collected,and field experiments were conducted at central and eastern Gansu and southern Ningxia,China.The mean temperature increased by 0.36°C,and precipitation decreased by 11.17 mm per decade.The average evapotranspiration(ET)of winter wheat in 39 years from 1981 to 2019 was 362.1 mm,demonstrating a 22.1-mm decrease every 10 years.However,the ET of spring maize was 405.5 mm over 35 years(1985-2019),which did not show a downward trend.Every 10 years,growth periods were shortened by 5.19 and 6.47 d,sowing dates were delayed by 3.56 and 1.68 d,and maturity dates advanced by 1.76 and 5.51 d,respectively,for wheat and maize.A film fully-mulched ridge-furrow(FMRF)system with a rain-harvesting efficiency of 65.7‒92.7%promotes deep rainwater infiltration into the soil.This leads to double the soil moisture in-furrow,increasing the water satisfaction rate by 110‒160%.A 15-year grain yield of maize increased by 19.87%with the FMRF compared with that of half-mulched flat planting.Grain yield and water use efficiency of maize increased by 20.6 and 17.4%when the density grew from 4.5×10^(4)to 6.75×10^(4)plants ha-1 and improved by 12.0 and 12.7%when the density increased from 6.75×10^(4)to 9.0×10^(4)plants ha-1,respectively.Moreover,responses of maize yield to density and the corresponding density of the maximum yield varied highly in different rainfall areas.The density parameter suitable for water planting was 174 maize plants ha-1 with 10 mm rainfall.Therefore,management strategies should focus on adjusting crop planting structure,FMRF water harvesting system,and water-suitable planting to mitigate the adverse effects of climate change and enhance sustainable production of maize in the drylands.展开更多
Planting mulch grasses in orchards,as a technique to build ecological orchards,can be one of the strategic approaches for rural revitalization.This study sorted out the common varieties of mulch grasses and analyzed t...Planting mulch grasses in orchards,as a technique to build ecological orchards,can be one of the strategic approaches for rural revitalization.This study sorted out the common varieties of mulch grasses and analyzed their application statuses in orchards of southern China.According to different utilization purposes of mulch grasses in orchards,scientific suggestions were given from aspects of grass selection,cultivation techniques,management methods and use modes.The study will provide reference for the construction of ecological orchards in southern China.展开更多
The study was conducted to evaluate the field performance of local plantain genotypes;Apem, Oniaba, Apantu (AAB) and FHIA 21 (AAAB) suckers that were raised in containers (polybags) and their corresponding conventiona...The study was conducted to evaluate the field performance of local plantain genotypes;Apem, Oniaba, Apantu (AAB) and FHIA 21 (AAAB) suckers that were raised in containers (polybags) and their corresponding conventional suckers. Half of the containerized and conventional suckers in each plot were mulched with empty fruit bunch (EFB). Survival rate three months after transplanting was higher in containerized (100%) than conventional materials (60%) with or without mulching. Mulching increased the girth at flowering and total leaf area by 8% and 28% respectively, and reduced the number of days to flowering. Mulching also increased yield of plantain and the highest was recorded in FHIA 21. Bunch yield of container raised suckers per hectare was 19% greater than conventional suckers, due to higher survival rate after transplanting. Bunch yield among the genotypes in decreasing order was as follows, FHIA21 (20.7), Oniaba (16.9), Apem (15.9) and Apantu (13.2) tons/ha. Mulching increased the yield components such as, pulp weight, peel weight, finger weight and number of fingers. Genotypic variation in pulp yield was in the following decreasing order Apantu > FHIA 21 > Oniaba > Apem fresh weight. The pulp to peel ratio was in the following decreasing order Apantu > FHIA 21 > Apem > Oniaba. It is concluded that raising plantain suckers in polybags and applying EFB mulch is an improved production technique.展开更多
Nitrogen is an essential component in forest ecosystem nutrient cycling.Nitrogen fractions,such as dissolved nitrogen,ammonium,nitrate,and microbial biomass nitrogen,are sensitive indicators of soil nitrogen pools whi...Nitrogen is an essential component in forest ecosystem nutrient cycling.Nitrogen fractions,such as dissolved nitrogen,ammonium,nitrate,and microbial biomass nitrogen,are sensitive indicators of soil nitrogen pools which affect soil fertility and nutrient cycling.However,the responses of nitrogen fractions in forest soils to organic mulching are less well understood.The rhizosphere is an important micro-region that must be considered to better understand element cycling between plants and the soil.A field investigation was carried out on the effect of mulching soil in a 15-year-old Ligustrum lucidum urban plantation.Changes in total nitrogen and nitrogen fractions in rhizosphere and bulk soil in the topsoil(upper 20 cm)and in the subsoil(20-40 cm)were evaluated following different levels of mulching,in addition to nitrogen contents in fine roots,leaves,and organic mulch.The relationships between nitrogen fractions and other measured variables were analysed.Organic mulching had no significant effect on most nitrogen fractions except for the rhizosphere microbial biomass nitrogen(MBN),and the thinnest(5 cm)mulching layer showed greater effects than other treatments.Rhizosphere MBN was more sensitive to mulching compared to bulk soil,and was more affected by soil environmental changes.Season and soil depth had more pronounced effects on nitrogen fractions than mulching.Total nitrogen and dissolved nitrogen were correlated to soil phosphorus,whereas other nitrogen fractions were strongly affected by soil physical properties(temperature,water content,bulk density).Mulching also decreased leaf nitrogen content,which was more related to soil nitrogen fractions(except for MBN)than nitrogen contents in either fine roots or organic mulch.Frequent applications of small quantities of organic mulch contribute to nitrogen transformation and utilization in urban forests.展开更多
Yongzhou often encounters drought condition in July and August. Sometimes no rainfall lasts for 20 to 40 days, causes a great damage to grape production Our four-year rice straw mulching test on vineyard indicates tha...Yongzhou often encounters drought condition in July and August. Sometimes no rainfall lasts for 20 to 40 days, causes a great damage to grape production Our four-year rice straw mulching test on vineyard indicates that if favorable mulching is supplied properly, it reduces soil temperature and conserves soil moisture in summer, increases soil temperature in winter, keeps soil loose and mellow, depresses weeds, and increases soil organic matter content in vineyard to secure good quality and higher yield even under drought condition.展开更多
虚拟电厂(virtual power plant,VPP)是一种新型运行模式,通过有效聚合电网中大量需求侧资源并制定有效的动态聚合调控策略,实现电网不同时空的功率互补,提高电网调控的灵活性和系统的经济性。从电网调度角度分析了典型电网需求响应行为...虚拟电厂(virtual power plant,VPP)是一种新型运行模式,通过有效聚合电网中大量需求侧资源并制定有效的动态聚合调控策略,实现电网不同时空的功率互补,提高电网调控的灵活性和系统的经济性。从电网调度角度分析了典型电网需求响应行为特性,提出了需求响应能力指标和虚拟电厂分类聚合方法,构建了多源虚拟电厂调控模型,以其结果支撑虚拟电厂响应资源的分层分区互补调控。最后,以某园区为案例,分析了虚拟电厂调控策略的合理性和多源虚拟电厂调控的科学性。结果表明,整体动态调控策略可以引导虚拟电厂科学合理地发挥需求响应价值,促进电网负荷平稳和系统安全稳定运行。展开更多
基金We gratefully acknowledge the funding support from the National Key Research and Development Program of China(2012BAD0903 and 2018YFD0100200)the China Agriculture Research System(CARS-02-77).
文摘Climate change has a significant impact on agriculture.However,the impact investigation is currently limited to the analysis of meteorological data,and there is a dearth of long-term monitoring of crop phenology and soil moisture associated with climate change.In this study,temperature and precipitation(1957-2020)were recorded,crop growth(1981-2019)data were collected,and field experiments were conducted at central and eastern Gansu and southern Ningxia,China.The mean temperature increased by 0.36°C,and precipitation decreased by 11.17 mm per decade.The average evapotranspiration(ET)of winter wheat in 39 years from 1981 to 2019 was 362.1 mm,demonstrating a 22.1-mm decrease every 10 years.However,the ET of spring maize was 405.5 mm over 35 years(1985-2019),which did not show a downward trend.Every 10 years,growth periods were shortened by 5.19 and 6.47 d,sowing dates were delayed by 3.56 and 1.68 d,and maturity dates advanced by 1.76 and 5.51 d,respectively,for wheat and maize.A film fully-mulched ridge-furrow(FMRF)system with a rain-harvesting efficiency of 65.7‒92.7%promotes deep rainwater infiltration into the soil.This leads to double the soil moisture in-furrow,increasing the water satisfaction rate by 110‒160%.A 15-year grain yield of maize increased by 19.87%with the FMRF compared with that of half-mulched flat planting.Grain yield and water use efficiency of maize increased by 20.6 and 17.4%when the density grew from 4.5×10^(4)to 6.75×10^(4)plants ha-1 and improved by 12.0 and 12.7%when the density increased from 6.75×10^(4)to 9.0×10^(4)plants ha-1,respectively.Moreover,responses of maize yield to density and the corresponding density of the maximum yield varied highly in different rainfall areas.The density parameter suitable for water planting was 174 maize plants ha-1 with 10 mm rainfall.Therefore,management strategies should focus on adjusting crop planting structure,FMRF water harvesting system,and water-suitable planting to mitigate the adverse effects of climate change and enhance sustainable production of maize in the drylands.
基金Supported by National Key Research&Development Project(2018YFD0800501)Hunan Key Research&Development Project(2016JC2028)Science and Technology Innovation Project in Hunan Academy of Agricultural Sciences(2018QN33)~~
文摘Planting mulch grasses in orchards,as a technique to build ecological orchards,can be one of the strategic approaches for rural revitalization.This study sorted out the common varieties of mulch grasses and analyzed their application statuses in orchards of southern China.According to different utilization purposes of mulch grasses in orchards,scientific suggestions were given from aspects of grass selection,cultivation techniques,management methods and use modes.The study will provide reference for the construction of ecological orchards in southern China.
文摘The study was conducted to evaluate the field performance of local plantain genotypes;Apem, Oniaba, Apantu (AAB) and FHIA 21 (AAAB) suckers that were raised in containers (polybags) and their corresponding conventional suckers. Half of the containerized and conventional suckers in each plot were mulched with empty fruit bunch (EFB). Survival rate three months after transplanting was higher in containerized (100%) than conventional materials (60%) with or without mulching. Mulching increased the girth at flowering and total leaf area by 8% and 28% respectively, and reduced the number of days to flowering. Mulching also increased yield of plantain and the highest was recorded in FHIA 21. Bunch yield of container raised suckers per hectare was 19% greater than conventional suckers, due to higher survival rate after transplanting. Bunch yield among the genotypes in decreasing order was as follows, FHIA21 (20.7), Oniaba (16.9), Apem (15.9) and Apantu (13.2) tons/ha. Mulching increased the yield components such as, pulp weight, peel weight, finger weight and number of fingers. Genotypic variation in pulp yield was in the following decreasing order Apantu > FHIA 21 > Oniaba > Apem fresh weight. The pulp to peel ratio was in the following decreasing order Apantu > FHIA 21 > Apem > Oniaba. It is concluded that raising plantain suckers in polybags and applying EFB mulch is an improved production technique.
基金This study was supported by the National Natural Science Foundation of China(No.31971453)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)and Postgraduate Research&Practice Innovation Program of Jiangsu Province.
文摘Nitrogen is an essential component in forest ecosystem nutrient cycling.Nitrogen fractions,such as dissolved nitrogen,ammonium,nitrate,and microbial biomass nitrogen,are sensitive indicators of soil nitrogen pools which affect soil fertility and nutrient cycling.However,the responses of nitrogen fractions in forest soils to organic mulching are less well understood.The rhizosphere is an important micro-region that must be considered to better understand element cycling between plants and the soil.A field investigation was carried out on the effect of mulching soil in a 15-year-old Ligustrum lucidum urban plantation.Changes in total nitrogen and nitrogen fractions in rhizosphere and bulk soil in the topsoil(upper 20 cm)and in the subsoil(20-40 cm)were evaluated following different levels of mulching,in addition to nitrogen contents in fine roots,leaves,and organic mulch.The relationships between nitrogen fractions and other measured variables were analysed.Organic mulching had no significant effect on most nitrogen fractions except for the rhizosphere microbial biomass nitrogen(MBN),and the thinnest(5 cm)mulching layer showed greater effects than other treatments.Rhizosphere MBN was more sensitive to mulching compared to bulk soil,and was more affected by soil environmental changes.Season and soil depth had more pronounced effects on nitrogen fractions than mulching.Total nitrogen and dissolved nitrogen were correlated to soil phosphorus,whereas other nitrogen fractions were strongly affected by soil physical properties(temperature,water content,bulk density).Mulching also decreased leaf nitrogen content,which was more related to soil nitrogen fractions(except for MBN)than nitrogen contents in either fine roots or organic mulch.Frequent applications of small quantities of organic mulch contribute to nitrogen transformation and utilization in urban forests.
文摘Yongzhou often encounters drought condition in July and August. Sometimes no rainfall lasts for 20 to 40 days, causes a great damage to grape production Our four-year rice straw mulching test on vineyard indicates that if favorable mulching is supplied properly, it reduces soil temperature and conserves soil moisture in summer, increases soil temperature in winter, keeps soil loose and mellow, depresses weeds, and increases soil organic matter content in vineyard to secure good quality and higher yield even under drought condition.
文摘虚拟电厂(virtual power plant,VPP)是一种新型运行模式,通过有效聚合电网中大量需求侧资源并制定有效的动态聚合调控策略,实现电网不同时空的功率互补,提高电网调控的灵活性和系统的经济性。从电网调度角度分析了典型电网需求响应行为特性,提出了需求响应能力指标和虚拟电厂分类聚合方法,构建了多源虚拟电厂调控模型,以其结果支撑虚拟电厂响应资源的分层分区互补调控。最后,以某园区为案例,分析了虚拟电厂调控策略的合理性和多源虚拟电厂调控的科学性。结果表明,整体动态调控策略可以引导虚拟电厂科学合理地发挥需求响应价值,促进电网负荷平稳和系统安全稳定运行。
