The molecular dynamics simulation method was adopted to study the transient characteristics of Li^+,CO3^2-,and SO4^2- in Na^+,K^+,Li^+,Cl^-,and SO4^2-/H2O system.The composition of Na^+,K^+,Li^+,Cl^-,SO4^2- and CO3^2-...The molecular dynamics simulation method was adopted to study the transient characteristics of Li^+,CO3^2-,and SO4^2- in Na^+,K^+,Li^+,Cl^-,and SO4^2-/H2O system.The composition of Na^+,K^+,Li^+,Cl^-,SO4^2- and CO3^2- was selected to optimize the initial structural model and conduct dynamic simulation.The mean azimuth shift and diffusion coefficient of Li^+,CO3^2-,and SO4^2- in the system,the radial distribution function and potential energy between Li^+ and -OW,SO4^2- and -OW as well as CO3^2- and -OW,and the dielectric constant of hydrogen bond were expounded and analyzed.At the same time,the Li enrichment behavior in the evaporation process of salt lake brine was analyzed based on the simulated data.The results show that the simulation results are in good agreement with the experimental values,which verifies that,compared with other ions,the crystallization of Li^+ and SO4^2- occurs earlier after reaching saturation.展开更多
In the dominant winter wheat (WW)-summer maize (SM) double cropping system in the low plain located in the North China, limited access to fresh water, especially during dry season, constitutes a major obstacle to ...In the dominant winter wheat (WW)-summer maize (SM) double cropping system in the low plain located in the North China, limited access to fresh water, especially during dry season, constitutes a major obstacle to realize high crop productivity. Using the vast water resources of the saline upper aquifer for irrigation during WW jointing stage, may help to bridge the peak of dry season and relieve the tight water situation in the region. A field experiment was conducted during 2009-2012 to investigate the effects of saline irrigation during WW jointing stage on soil salt accumulation and productivity of WW and SM. The experiment treatments comprised no irrigation (T1), fresh water irrigation (T2), slightly saline water irrigation (T3:2.8 dS m-l), and strongly saline water irrigation (T4:8.2 dS m-1) at WW jointing stage. With regard to WW yields and aggregated annual WW-SM yields, clear benefits of saline water irrigation (T3 & T4) compared to no irrigation (T1), as well as insignificant yield losses compared to fresh water irrigation (T2) occurred in all three experiment years. However, the increased soil salinity in eady SM season in consequence of saline irrigation exerted a negative effect on SM photosynthesis and final yield in two of three experiment years. To avoid the negative aftereffects of saline irrigation, sufficient fresh water irrigation during SM sowing phase (i.e., increase from 60 to 90 mm) is recommended to guarantee good growth conditions during the sensitive early growing period of SM. The risk of long-term accumulation of salts as a result of saline irrigation during the peak of dry season is considered low, due to deep leaching of salts during regularly occurring wet years, as demonstrated in the 2012 experiment year. Thus, applying saline water irrigation at jointing stage of WW and fresh water at sowing of SM is most promising to realize high yield and fresh irrigation water saving.展开更多
In this paper, aiming at the problems of insufficient soil nutrients and high salt content in Wudi core demonstration area of Bohai Granary, a monitoring and management system of water, fertilizer and salt in saline-a...In this paper, aiming at the problems of insufficient soil nutrients and high salt content in Wudi core demonstration area of Bohai Granary, a monitoring and management system of water, fertilizer and salt in saline-alkaline farmland based on WebGIS was established in order to monitor and control water, fertilizer and salt. Based on the Windows.NET platform, using B/S mode of operation architecture and Visual Studio 2010 as the software development environment, the related components in ArcGIS Engine were invoked by ArcGIS API for Silverlirht, and the WEB system was developed by C# and XMAL language. Based on the principle of water, fertilizer and salt balance, a monitoring model and a regulation model for water, salt and nutrients were established. Intelligent analysis and application of farmland soil data were realized, and a precision agriculture system with data query, early warning diagnosis, monitoring and control of water, fertilizer and salt was formed. And the "water and salt homologue, water supply due to demand, adequate and multiple" irrigation scheme and the salt and alkali reduction scheme of "synergistic conditioning of agents and nutrients" and a nutrient regulation plan for "stabilizing nitrogen, increasing phosphorus, supplementing potassium at the discretion" and "quick-acting combining slow release" were put forward. Compared with the period without monitoring and control of water and salt, the effect of water saving and fertilizer saving was improved, and the yield of wheat and maize was also significantly increased. It provided guidance for local users to increase crop production and income, and greatly improved the utilization of resources and grain production.展开更多
Fresh water resource scarcity and soil salt accumulation in the root-zone are two key limiting factors for sustainable agricultural development in the oasis region of arid inland basin, northwest China. The aim of thi...Fresh water resource scarcity and soil salt accumulation in the root-zone are two key limiting factors for sustainable agricultural development in the oasis region of arid inland basin, northwest China. The aim of this study was to explore an appropriate irrigation scheme to maintain sustainable crop cultivation in this region. The effects of four irrigation levels (full irrigation, mild deficit, moderate deficit, and severe deficit) and three irrigation methods (border, surface drip and subsurface drip) on soil water and salt dynamics, highland barley (Hordeum vulgare L.) yield, and crop water use efficiency were studied by field plot experiments. The results showed that soil salt in 0-100 cm profile was accumulated under all experimental treatments after one season of highland barley planting, but the accumulated salt mass decreased with the decrease of the lower limit of irrigation. Salt mass in 0-100 cm soil profile under subsurface drip irrigation was 16.8%-57.8% and 2.9%-58.4% less than that under border and surface drip irrigation, respectively. The grain yield of highland barley decreased first and then increased with the decrease of the lower limit of irrigation under surface drip and subsurface drip irrigation, but it was on the contrary under border irrigation. Mean grain yield for all irrigation levels under subsurface drip irrigation was 5.7% and 18.8% higher than that under border and surface drip irrigation, respectively. Water use efficiency increased with the decrease of the lower limit of irrigation, and the averaged water use efficiency of all irrigation levels under subsurface drip irrigation was 11.9% and 14.2% higher than that under border and surface drip irrigation, respectively. Considering economic benefit and irrigation water requirement, subsurface drip irrigation with the lower limit of irrigation of 50%-55% field capacity is suggested for highland barley planting in the arid oasis region.展开更多
基金Funded by the Innovation Academy for Green Manufacture,CAS“IAGM2020C01”the Key R&D and the Transformation Projects in Qinghai Province(2019-GX-167)CAS“Light of West China”。
文摘The molecular dynamics simulation method was adopted to study the transient characteristics of Li^+,CO3^2-,and SO4^2- in Na^+,K^+,Li^+,Cl^-,and SO4^2-/H2O system.The composition of Na^+,K^+,Li^+,Cl^-,SO4^2- and CO3^2- was selected to optimize the initial structural model and conduct dynamic simulation.The mean azimuth shift and diffusion coefficient of Li^+,CO3^2-,and SO4^2- in the system,the radial distribution function and potential energy between Li^+ and -OW,SO4^2- and -OW as well as CO3^2- and -OW,and the dielectric constant of hydrogen bond were expounded and analyzed.At the same time,the Li enrichment behavior in the evaporation process of salt lake brine was analyzed based on the simulated data.The results show that the simulation results are in good agreement with the experimental values,which verifies that,compared with other ions,the crystallization of Li^+ and SO4^2- occurs earlier after reaching saturation.
基金funded by the National Scientific and Technological Supporting Scheme,China (2013BAD05B02 )the Demonstration Plan of Modern Agriculture of Chinese Academy of Sciences (CXJQ120108-2)the support by the Sino-German Center for Research Promotion,Germany (GZ 1149)
文摘In the dominant winter wheat (WW)-summer maize (SM) double cropping system in the low plain located in the North China, limited access to fresh water, especially during dry season, constitutes a major obstacle to realize high crop productivity. Using the vast water resources of the saline upper aquifer for irrigation during WW jointing stage, may help to bridge the peak of dry season and relieve the tight water situation in the region. A field experiment was conducted during 2009-2012 to investigate the effects of saline irrigation during WW jointing stage on soil salt accumulation and productivity of WW and SM. The experiment treatments comprised no irrigation (T1), fresh water irrigation (T2), slightly saline water irrigation (T3:2.8 dS m-l), and strongly saline water irrigation (T4:8.2 dS m-1) at WW jointing stage. With regard to WW yields and aggregated annual WW-SM yields, clear benefits of saline water irrigation (T3 & T4) compared to no irrigation (T1), as well as insignificant yield losses compared to fresh water irrigation (T2) occurred in all three experiment years. However, the increased soil salinity in eady SM season in consequence of saline irrigation exerted a negative effect on SM photosynthesis and final yield in two of three experiment years. To avoid the negative aftereffects of saline irrigation, sufficient fresh water irrigation during SM sowing phase (i.e., increase from 60 to 90 mm) is recommended to guarantee good growth conditions during the sensitive early growing period of SM. The risk of long-term accumulation of salts as a result of saline irrigation during the peak of dry season is considered low, due to deep leaching of salts during regularly occurring wet years, as demonstrated in the 2012 experiment year. Thus, applying saline water irrigation at jointing stage of WW and fresh water at sowing of SM is most promising to realize high yield and fresh irrigation water saving.
基金supported by the Independent Innovation and Achievement Transformation Special Project of Shandong Province (Grant Nos. 2014ZZCX07106, 2014ZZCX07402)
文摘In this paper, aiming at the problems of insufficient soil nutrients and high salt content in Wudi core demonstration area of Bohai Granary, a monitoring and management system of water, fertilizer and salt in saline-alkaline farmland based on WebGIS was established in order to monitor and control water, fertilizer and salt. Based on the Windows.NET platform, using B/S mode of operation architecture and Visual Studio 2010 as the software development environment, the related components in ArcGIS Engine were invoked by ArcGIS API for Silverlirht, and the WEB system was developed by C# and XMAL language. Based on the principle of water, fertilizer and salt balance, a monitoring model and a regulation model for water, salt and nutrients were established. Intelligent analysis and application of farmland soil data were realized, and a precision agriculture system with data query, early warning diagnosis, monitoring and control of water, fertilizer and salt was formed. And the "water and salt homologue, water supply due to demand, adequate and multiple" irrigation scheme and the salt and alkali reduction scheme of "synergistic conditioning of agents and nutrients" and a nutrient regulation plan for "stabilizing nitrogen, increasing phosphorus, supplementing potassium at the discretion" and "quick-acting combining slow release" were put forward. Compared with the period without monitoring and control of water and salt, the effect of water saving and fertilizer saving was improved, and the yield of wheat and maize was also significantly increased. It provided guidance for local users to increase crop production and income, and greatly improved the utilization of resources and grain production.
基金supported by the National Key Research and Development Program of China (Grant No.2018YFC0406604).
文摘Fresh water resource scarcity and soil salt accumulation in the root-zone are two key limiting factors for sustainable agricultural development in the oasis region of arid inland basin, northwest China. The aim of this study was to explore an appropriate irrigation scheme to maintain sustainable crop cultivation in this region. The effects of four irrigation levels (full irrigation, mild deficit, moderate deficit, and severe deficit) and three irrigation methods (border, surface drip and subsurface drip) on soil water and salt dynamics, highland barley (Hordeum vulgare L.) yield, and crop water use efficiency were studied by field plot experiments. The results showed that soil salt in 0-100 cm profile was accumulated under all experimental treatments after one season of highland barley planting, but the accumulated salt mass decreased with the decrease of the lower limit of irrigation. Salt mass in 0-100 cm soil profile under subsurface drip irrigation was 16.8%-57.8% and 2.9%-58.4% less than that under border and surface drip irrigation, respectively. The grain yield of highland barley decreased first and then increased with the decrease of the lower limit of irrigation under surface drip and subsurface drip irrigation, but it was on the contrary under border irrigation. Mean grain yield for all irrigation levels under subsurface drip irrigation was 5.7% and 18.8% higher than that under border and surface drip irrigation, respectively. Water use efficiency increased with the decrease of the lower limit of irrigation, and the averaged water use efficiency of all irrigation levels under subsurface drip irrigation was 11.9% and 14.2% higher than that under border and surface drip irrigation, respectively. Considering economic benefit and irrigation water requirement, subsurface drip irrigation with the lower limit of irrigation of 50%-55% field capacity is suggested for highland barley planting in the arid oasis region.