Accurate evaluation of soil productivity has been a long-standing challenge. Although numerous models for productivity assessment exist, most are cumbersome to use and require substantial parameter inputs. We develope...Accurate evaluation of soil productivity has been a long-standing challenge. Although numerous models for productivity assessment exist, most are cumbersome to use and require substantial parameter inputs. We developed a new empirical soil productivity model based on field investigations of soil erosion, soil physieoehemieal properties, and crop yields in the dry-hot valleys （DHVs） in China. We found that soil pH, and organic matter and available potassium contents significantly affected crop yields under eroded conditions of the DHVs. Moreover, available potassium content was the key factor affecting soil productivity. We then modified an existing soil productivity model by adding the following parameters： contents of effective water, potassium, organic matter, and clay, soil pH, and root weighting factor. The modified soil productivity model explained 63.5% of the crop yield. We concluded that the new model was simple, realistic, and exhibited strong predictability. In addition to providing an accurate assessment of soil productivity,our model could potentially be applied as a soil module in comprehensive crop models.展开更多
Dual control of energy consumption is an effective method proposed in China to launch and deepen the transition in energy use.It has obtained favorable results;however,the resource consumption and pollution emissions ...Dual control of energy consumption is an effective method proposed in China to launch and deepen the transition in energy use.It has obtained favorable results;however,the resource consumption and pollution emissions per unit of Gross Domestic Product(GDP)remain high.This article quantitatively studies the current policies’effects to promote the advancement of dual control of energy consumption and develop future policies.Green production and consumption policies promote the development of dual control of energy consumption;therefore,this paper examines these policies through text mining and a quantitative evaluation system.The results suggest strong state demand for developing green production and consumption and the necessity for scientific evaluation;however,the state’s focus on the relevant policy tools is imbalanced.Constraint policy tools have the highest proportion of restricting pollutant emissions but lack comprehensiveness.Incentive and guidance policy tools have the problems of poor targets and low volume.Additionally,by constructing policy modeling consistency(PMC)index models for evaluating green production and consumption policies,six selected policies indicate solid performance,but some still have problems regarding policy timeframe,policy function,and green process.Based on the conclusions,this paper provides some targeted recommendations.展开更多
基金supported by the National Natural Science Foundation Project of China(Grant Nos.41561063,41401614 and 41401560)Non-profit Industry Research Project of Chinese Ministry of Water Resources(Grant No.201501045)Department of Water Resources of Yunnan Province:Water Science and Technology Project
文摘Accurate evaluation of soil productivity has been a long-standing challenge. Although numerous models for productivity assessment exist, most are cumbersome to use and require substantial parameter inputs. We developed a new empirical soil productivity model based on field investigations of soil erosion, soil physieoehemieal properties, and crop yields in the dry-hot valleys （DHVs） in China. We found that soil pH, and organic matter and available potassium contents significantly affected crop yields under eroded conditions of the DHVs. Moreover, available potassium content was the key factor affecting soil productivity. We then modified an existing soil productivity model by adding the following parameters： contents of effective water, potassium, organic matter, and clay, soil pH, and root weighting factor. The modified soil productivity model explained 63.5% of the crop yield. We concluded that the new model was simple, realistic, and exhibited strong predictability. In addition to providing an accurate assessment of soil productivity,our model could potentially be applied as a soil module in comprehensive crop models.
基金supported by the National Social Science Foundation of China[Grant No.20ZDA087].
文摘Dual control of energy consumption is an effective method proposed in China to launch and deepen the transition in energy use.It has obtained favorable results;however,the resource consumption and pollution emissions per unit of Gross Domestic Product(GDP)remain high.This article quantitatively studies the current policies’effects to promote the advancement of dual control of energy consumption and develop future policies.Green production and consumption policies promote the development of dual control of energy consumption;therefore,this paper examines these policies through text mining and a quantitative evaluation system.The results suggest strong state demand for developing green production and consumption and the necessity for scientific evaluation;however,the state’s focus on the relevant policy tools is imbalanced.Constraint policy tools have the highest proportion of restricting pollutant emissions but lack comprehensiveness.Incentive and guidance policy tools have the problems of poor targets and low volume.Additionally,by constructing policy modeling consistency(PMC)index models for evaluating green production and consumption policies,six selected policies indicate solid performance,but some still have problems regarding policy timeframe,policy function,and green process.Based on the conclusions,this paper provides some targeted recommendations.
