Based on the results of nine Coupled Model Intercomparison Project Phase 5 (CMIP5) coupling models, the temperature and precipitation data of 114 stations in Northeast China were compared and analyzed. The simulation ...Based on the results of nine Coupled Model Intercomparison Project Phase 5 (CMIP5) coupling models, the temperature and precipitation data of 114 stations in Northeast China were compared and analyzed. The simulation effect of CMIP5 model on precipitation and temperature in Northeast China was evaluated. The research shows that the Geophysical Fluid Dynamics Laboratory Earth System Models (GGFDL-ESM2G) have the best simulation effect on precipitation and temperature in Northeast China. Based on the SPEI index, the relationship between the drought trend of maize growing season and the yield change rate of maize in Northeast China was analyzed, and the future drought (2020-2050) and corn yield in Northeast China were estimated. The cumulative Standardized Precipitation Evapotranspiration Index (SPEI) analysis of the northeast maize growing season (May-September) shows that the drought in the northeastern region showed an intensifying trend from 1980 to 2010, especially in the first ten years of the 21st century. The cumulative SPEI index has a significant positive correlation with the yield of maize in Northeast China, and has a certain indicator effect on the yield of maize in Northeast China. The three scenarios of GFDL-ESM2G model show that under the three scenarios of Representative Concentration Pathways (RCP), the warming in Northeast China is significant;under the RCP4.5 scenario, the precipitation in Northeast China is increasing;in the RCP2.6 and RCP8.5 climate scenarios, precipitation is presented and reduces the trend of drought. Estimates of drought trends in Northeast China show that under the RCP4.5 climate scenario, the drought in Northeast China showed a slowing trend from 2020 to 2050. Under the RCP2.6 and RCP8.5 climate scenarios, the drought in Northeast China showed an increasing trend. Under the RCP2.6 and RCP8.5 climate scenarios, the yield change rate of maize in Northeast China showed a downward trend, indicating that climate warming caused the drought in Northeast China to increase, which had a negative impact on corn yield increase. In severe drought years, drought may cause northeast corn production seriously reduced. However, under the RCP4.5 scenario, drought has little effect on corn yield.展开更多
The Loess Plateau of China has experienced a lengthy drought and severe soil erosion.Changes in precipitation and land use largely determine the dynamics of runoff and sediment yield in this region. Trend and mutation...The Loess Plateau of China has experienced a lengthy drought and severe soil erosion.Changes in precipitation and land use largely determine the dynamics of runoff and sediment yield in this region. Trend and mutation analyses were performed on hydrological data(1981–2012) from the Yanwachuan watershed in the Loess Plateau Gully Region to study the evolution characteristics of runoff and sediment yield. A time-series contrasting method also was used to evaluate the effects of precipitation and soil and water conservation(SWC) on runoff and sediment yield. Annual sediment yield declined markedly from 1981 to 2012 although there was no significant change in annual precipitation and annual runoff. Change points of annual runoff and annual sediment yield occurred in 1996 and 1997,respectively. Compared with that in the baseline period(1981–1996), annual runoff and annual sediment yield in the change period(1997–2012)decreased by 17.0% and 76.0%, respectively, but annual precipitation increased by 6.3%. Runoff decreased in the flood season and normal season, but increased in the dry season, while sediment yield significantly declined in the whole study period. The SWC measures contributed significantly to the reduction of annual runoff(137.9%) and annual sediment yield(135%) and were more important than precipitation. Biological measures(forestland and grassland) accounted for 61.04% of total runoff reduction, while engineering measures(terraces and dams) accounted for 102.84% of total sediment yield reduction. Furthermore, SWC measures had positive ecological effects. This study provides a scientific basis for soil erosion control on the Loess Plateau.展开更多
系统分析了我国广西桂林、钦州及玉林3个潴育性水稻土长期常规施肥（F）和不施肥（CK）处理下,双季稻产量及土壤肥力随时间的变化趋势,并借助通径分析探明主要肥力因素对各点水稻产量的驱动差异和关联。结果显示,不施肥条件下,桂林点的...系统分析了我国广西桂林、钦州及玉林3个潴育性水稻土长期常规施肥（F）和不施肥（CK）处理下,双季稻产量及土壤肥力随时间的变化趋势,并借助通径分析探明主要肥力因素对各点水稻产量的驱动差异和关联。结果显示,不施肥条件下,桂林点的基础地力较低,其产量随时间呈显著下降趋势（各季产量均值666-846 kg hm-2）,而玉林和钦州点基础地力相对较高,其产量在试验期间相对稳定（各季产量均值3 500-4 577 kg hm-2）。常规施肥下,桂林点产量显著提高（较CK增产522%）,且随时间呈显著上升趋势,另两试验点较CK增产20%-67%。常规施肥下,土壤肥力随时间呈稳定或不同程度的上升趋势,其中土壤有效磷初始值低于10 mg kg-1的桂林和钦州点上升幅度最大且均达到显著水平,而初始值为50 mg kg-1的玉林点变化不大。土壤有机质与全氮变化在各地不同,气温偏低的桂林点有机质呈上升趋势且全氮含量较高（〉3 g kg-1）,气温偏高的玉林和钦州点有机质呈下降趋势且全氮含量较低（1-2.5 g kg-1）,表明有机质的累积和释放上存在差异。双季稻产量的主要肥力驱动因子各地有差异,桂北地区桂林点土壤有效磷为首要因素,桂南地区玉林和钦州点土壤有机质及氮含量为主要的肥力因素。因此,依据区域特征采取有针对性措施是持续、高效培肥土壤的保证。展开更多
研究长期施肥对双季稻产量变化趋势、稳定性和可持续性的影响。采用线性回归、稳定性方差和可持续性指数等方法对长期施肥定位试验获取的双季稻产量数据进行分析。结果表明:(1)与偏施化肥处理相比,均衡施NPK化肥处理提高了双季稻产量、...研究长期施肥对双季稻产量变化趋势、稳定性和可持续性的影响。采用线性回归、稳定性方差和可持续性指数等方法对长期施肥定位试验获取的双季稻产量数据进行分析。结果表明:(1)与偏施化肥处理相比,均衡施NPK化肥处理提高了双季稻产量、产量稳定性和可持续性,在等氮量条件下配施30%、50%和70%有机肥较NPK处理进一步提高产量6.15%、3.88%和7.75%,稳定性25.91%、59.78%和29.31%,配施30%有机肥较NPK处理提高可持续指数8.57%;(2)处理间整体表现出初始产量越高,产量的年变化量越小。施NK处理产量随时间呈下降趋势,其他处理均为上升趋势,其中不施肥和施PK处理变化显著,年变化量最大,分别为108.0和142.3 kg hm-2 a-1,NPK处理最小,为23.74 kg hm-2 a-1,有机无机肥配施处理间表现为随有机肥配施比例增加而产量年变化量显著增大的变化趋势。综上可见,有机无机肥配施有利于双季稻高产稳产,可有效维持系统可持续性,以70%化肥配施30%有机肥效果最佳。展开更多
文摘Based on the results of nine Coupled Model Intercomparison Project Phase 5 (CMIP5) coupling models, the temperature and precipitation data of 114 stations in Northeast China were compared and analyzed. The simulation effect of CMIP5 model on precipitation and temperature in Northeast China was evaluated. The research shows that the Geophysical Fluid Dynamics Laboratory Earth System Models (GGFDL-ESM2G) have the best simulation effect on precipitation and temperature in Northeast China. Based on the SPEI index, the relationship between the drought trend of maize growing season and the yield change rate of maize in Northeast China was analyzed, and the future drought (2020-2050) and corn yield in Northeast China were estimated. The cumulative Standardized Precipitation Evapotranspiration Index (SPEI) analysis of the northeast maize growing season (May-September) shows that the drought in the northeastern region showed an intensifying trend from 1980 to 2010, especially in the first ten years of the 21st century. The cumulative SPEI index has a significant positive correlation with the yield of maize in Northeast China, and has a certain indicator effect on the yield of maize in Northeast China. The three scenarios of GFDL-ESM2G model show that under the three scenarios of Representative Concentration Pathways (RCP), the warming in Northeast China is significant;under the RCP4.5 scenario, the precipitation in Northeast China is increasing;in the RCP2.6 and RCP8.5 climate scenarios, precipitation is presented and reduces the trend of drought. Estimates of drought trends in Northeast China show that under the RCP4.5 climate scenario, the drought in Northeast China showed a slowing trend from 2020 to 2050. Under the RCP2.6 and RCP8.5 climate scenarios, the drought in Northeast China showed an increasing trend. Under the RCP2.6 and RCP8.5 climate scenarios, the yield change rate of maize in Northeast China showed a downward trend, indicating that climate warming caused the drought in Northeast China to increase, which had a negative impact on corn yield increase. In severe drought years, drought may cause northeast corn production seriously reduced. However, under the RCP4.5 scenario, drought has little effect on corn yield.
基金supported by the National Natural Science Foundation of China (51239009, 41171034)Shaanxi Provincial Natural Science Foundation of China (Key) Project (2013JZ012)+1 种基金Shaanxi Provincial Key Laboratory Project of Department of Education (14JS059)Shaanxi Provincial Water Conservancy Science and Technology Project (2016slkj-11)
文摘The Loess Plateau of China has experienced a lengthy drought and severe soil erosion.Changes in precipitation and land use largely determine the dynamics of runoff and sediment yield in this region. Trend and mutation analyses were performed on hydrological data(1981–2012) from the Yanwachuan watershed in the Loess Plateau Gully Region to study the evolution characteristics of runoff and sediment yield. A time-series contrasting method also was used to evaluate the effects of precipitation and soil and water conservation(SWC) on runoff and sediment yield. Annual sediment yield declined markedly from 1981 to 2012 although there was no significant change in annual precipitation and annual runoff. Change points of annual runoff and annual sediment yield occurred in 1996 and 1997,respectively. Compared with that in the baseline period(1981–1996), annual runoff and annual sediment yield in the change period(1997–2012)decreased by 17.0% and 76.0%, respectively, but annual precipitation increased by 6.3%. Runoff decreased in the flood season and normal season, but increased in the dry season, while sediment yield significantly declined in the whole study period. The SWC measures contributed significantly to the reduction of annual runoff(137.9%) and annual sediment yield(135%) and were more important than precipitation. Biological measures(forestland and grassland) accounted for 61.04% of total runoff reduction, while engineering measures(terraces and dams) accounted for 102.84% of total sediment yield reduction. Furthermore, SWC measures had positive ecological effects. This study provides a scientific basis for soil erosion control on the Loess Plateau.
文摘系统分析了我国广西桂林、钦州及玉林3个潴育性水稻土长期常规施肥（F）和不施肥（CK）处理下,双季稻产量及土壤肥力随时间的变化趋势,并借助通径分析探明主要肥力因素对各点水稻产量的驱动差异和关联。结果显示,不施肥条件下,桂林点的基础地力较低,其产量随时间呈显著下降趋势（各季产量均值666-846 kg hm-2）,而玉林和钦州点基础地力相对较高,其产量在试验期间相对稳定（各季产量均值3 500-4 577 kg hm-2）。常规施肥下,桂林点产量显著提高（较CK增产522%）,且随时间呈显著上升趋势,另两试验点较CK增产20%-67%。常规施肥下,土壤肥力随时间呈稳定或不同程度的上升趋势,其中土壤有效磷初始值低于10 mg kg-1的桂林和钦州点上升幅度最大且均达到显著水平,而初始值为50 mg kg-1的玉林点变化不大。土壤有机质与全氮变化在各地不同,气温偏低的桂林点有机质呈上升趋势且全氮含量较高（〉3 g kg-1）,气温偏高的玉林和钦州点有机质呈下降趋势且全氮含量较低（1-2.5 g kg-1）,表明有机质的累积和释放上存在差异。双季稻产量的主要肥力驱动因子各地有差异,桂北地区桂林点土壤有效磷为首要因素,桂南地区玉林和钦州点土壤有机质及氮含量为主要的肥力因素。因此,依据区域特征采取有针对性措施是持续、高效培肥土壤的保证。
文摘研究长期施肥对双季稻产量变化趋势、稳定性和可持续性的影响。采用线性回归、稳定性方差和可持续性指数等方法对长期施肥定位试验获取的双季稻产量数据进行分析。结果表明:(1)与偏施化肥处理相比,均衡施NPK化肥处理提高了双季稻产量、产量稳定性和可持续性,在等氮量条件下配施30%、50%和70%有机肥较NPK处理进一步提高产量6.15%、3.88%和7.75%,稳定性25.91%、59.78%和29.31%,配施30%有机肥较NPK处理提高可持续指数8.57%;(2)处理间整体表现出初始产量越高,产量的年变化量越小。施NK处理产量随时间呈下降趋势,其他处理均为上升趋势,其中不施肥和施PK处理变化显著,年变化量最大,分别为108.0和142.3 kg hm-2 a-1,NPK处理最小,为23.74 kg hm-2 a-1,有机无机肥配施处理间表现为随有机肥配施比例增加而产量年变化量显著增大的变化趋势。综上可见,有机无机肥配施有利于双季稻高产稳产,可有效维持系统可持续性,以70%化肥配施30%有机肥效果最佳。
