Eutrophication is recognized as one of the major environmental problems in the Three Gorges Reservoir.Contour hedgerows have been used as a major soil and water conservation measure in this area.Accordingly,a two-year...Eutrophication is recognized as one of the major environmental problems in the Three Gorges Reservoir.Contour hedgerows have been used as a major soil and water conservation measure in this area.Accordingly,a two-year study was conducted to investigate the effects of contour hedgerow intercropping on nutrient loss from sloping farmland in this area.Four treatments were applied:(1) Maize + Soybean,(2) Maize,(3) Maize + Alfalfa,and(4) Maize + Hemerocallis citrina Baroni.Results indicated that nutrient loss in the control treatment(Maize) was serious,especially the average loss flux of total nitrogen(2245.8 mg) and total phosphate(2434.2 mg) in a typical rainfall event.However,the nutrient losses by runoff in the other three treatments with contour hedgerow intercropping showed significant reduction.Compared with the control treatment,the total nitrogen loss in the Alfalfa and Hemerocallis citrina Baroni decreased by 80.9% and 85.0%,respectively,and the total phosphorus loss in the two treatments decreased by 91.2% and 92.5%,respectively.Therefore,it is concluded that nutrient losses could be reduced by using contour hedgerows in the Three Gorges Region.Reducing runoff volume and sediment loss was the main mechanisms of contour hedgerow intercropping to reduce nutrient loss.展开更多
Soil test for availability of nutrients and heavy metals is extensively served as a means for the evaluations of soil fertility, and environmental effects and phytotoxicity of pollutants in soils, and for the fertiliz...Soil test for availability of nutrients and heavy metals is extensively served as a means for the evaluations of soil fertility, and environmental effects and phytotoxicity of pollutants in soils, and for the fertilizer recommendation in agricultural and environmental sciences. Therefore, great attention has been paid to the measurement of elemental availability in soil test.展开更多
This demonstration of concept applies diagnostic-prescriptive reading instruction, a methodology useo m omteu atd^u~ developmental education, toward improving reading comprehension and self-regulated comprehension str...This demonstration of concept applies diagnostic-prescriptive reading instruction, a methodology useo m omteu atd^u~ developmental education, toward improving reading comprehension and self-regulated comprehension strategy selection in Chinese postsecondary education. A single tutor, also the researcher, works closely with one Chinese university student to develop student-centered comprehension strategies that she can practice on her own. After a battery of formal and informal assessments and interviews, decoding and understanding deficiencies are identified, characterized, and discussed. Both the student and her tutor develop and execute a study plan, which was completed during the spring semester of 2010 at Sha＇anxi University of Science and Technology （SUST） in Xi＇an, People＇s Republic of China （PRC）. By focusing on the subject＇s primary decoding deficiency, spelling, and her primary understanding deficiency, lack of background knowledge, the subject and her reading tutor are able to strategically tackle five reading comprehension goals： （1） spelling; （2） phonemic awareness; （3） noticing structural and cohesive elements; （4） comparing argumentative and evaluative texts; and （5） analyzing expository texts in business and economics. A final discussion analyzes both qualitative and quantitative data, including unexpected discoveries such as the salience of cohesion in reading comprehension and the cultural biases of standardized reading assessments.展开更多
基金by the National Science & Technology Pillar Program (Grant No. 2009ZX07104-002)the CAS Actionplan for West Development (GrantNo. KZCX2-XB3-09)the Natural Science Foundation of China (Grant No. 40901255)
文摘Eutrophication is recognized as one of the major environmental problems in the Three Gorges Reservoir.Contour hedgerows have been used as a major soil and water conservation measure in this area.Accordingly,a two-year study was conducted to investigate the effects of contour hedgerow intercropping on nutrient loss from sloping farmland in this area.Four treatments were applied:(1) Maize + Soybean,(2) Maize,(3) Maize + Alfalfa,and(4) Maize + Hemerocallis citrina Baroni.Results indicated that nutrient loss in the control treatment(Maize) was serious,especially the average loss flux of total nitrogen(2245.8 mg) and total phosphate(2434.2 mg) in a typical rainfall event.However,the nutrient losses by runoff in the other three treatments with contour hedgerow intercropping showed significant reduction.Compared with the control treatment,the total nitrogen loss in the Alfalfa and Hemerocallis citrina Baroni decreased by 80.9% and 85.0%,respectively,and the total phosphorus loss in the two treatments decreased by 91.2% and 92.5%,respectively.Therefore,it is concluded that nutrient losses could be reduced by using contour hedgerows in the Three Gorges Region.Reducing runoff volume and sediment loss was the main mechanisms of contour hedgerow intercropping to reduce nutrient loss.
文摘Soil test for availability of nutrients and heavy metals is extensively served as a means for the evaluations of soil fertility, and environmental effects and phytotoxicity of pollutants in soils, and for the fertilizer recommendation in agricultural and environmental sciences. Therefore, great attention has been paid to the measurement of elemental availability in soil test.
文摘This demonstration of concept applies diagnostic-prescriptive reading instruction, a methodology useo m omteu atd^u~ developmental education, toward improving reading comprehension and self-regulated comprehension strategy selection in Chinese postsecondary education. A single tutor, also the researcher, works closely with one Chinese university student to develop student-centered comprehension strategies that she can practice on her own. After a battery of formal and informal assessments and interviews, decoding and understanding deficiencies are identified, characterized, and discussed. Both the student and her tutor develop and execute a study plan, which was completed during the spring semester of 2010 at Sha＇anxi University of Science and Technology （SUST） in Xi＇an, People＇s Republic of China （PRC）. By focusing on the subject＇s primary decoding deficiency, spelling, and her primary understanding deficiency, lack of background knowledge, the subject and her reading tutor are able to strategically tackle five reading comprehension goals： （1） spelling; （2） phonemic awareness; （3） noticing structural and cohesive elements; （4） comparing argumentative and evaluative texts; and （5） analyzing expository texts in business and economics. A final discussion analyzes both qualitative and quantitative data, including unexpected discoveries such as the salience of cohesion in reading comprehension and the cultural biases of standardized reading assessments.
