Ridge tillage, which is a very common and important tillage measure in the black soil area of northeast China, has some soil and water conservation bene- fits, but has little attention. It is very important to explore...Ridge tillage, which is a very common and important tillage measure in the black soil area of northeast China, has some soil and water conservation bene- fits, but has little attention. It is very important to explore the spatial distribution of the ridge direction of the arable land and its soil and water conservation benefits in different terrain conditions in the black soil area. So Binxian County of Heilongjiang Province was selected as the study area, and 168 field investigation units were ex- tracted by stratified sampling method and investigated. According to equations of slope gradient factor and slope gradient in ridge direction, and based on the soft- ware of Arcmap, SPSS and Excel, the investigation data of soil and water loss in Binxian County were analyzed and counted, The results show that in plain, hilly and mountainous areas, the average ground slope gradients are 1.92°, 6.20° and 8.27° respectively, and the average slope gradients along ridge direction are 1.33°, 4.52°and 6.45° respectively, which account for about 70%, 73% and 78% of the average ground slope gradients in the same terrain condition; the relative quantities of soil erosion in the present ridge tillage condition account for about 55%, 69% and 67% respectively of that in down-slope ridge tillage conditions, so the present ridge tillage has obviously relative soil and water conservation benefits. Based on these results, the reasons of the present ridge tillage status were analyzed, and some reform measures were proposed. The results could not only help to comprehend the spatial distribution and soil and water conservation benefits of ridge tillage in the black soil area of Northeast China, but also provide scientific references for the layout of local soil and water conservation measures.展开更多
TWENTY years ago, while working in the rich black soil of the northeast, I came to know a Mr. Li. He was the blacksmith with the production team I worked on, the Heilongjiang Production & Construction Corps.His da...TWENTY years ago, while working in the rich black soil of the northeast, I came to know a Mr. Li. He was the blacksmith with the production team I worked on, the Heilongjiang Production & Construction Corps.His daughter, Li Yemei, is now a student at Beijing University. She had been admitted to China’s most famous university because of her outstanding achievements in sports. A marathon runner, she had won 13 championships in national and international competitions. In China, any athlete who has broken a world record or performed outstandingly in any of the three most important international events—the Olympic Games, the World Championships, or the World Cup—is given access to a university education without taking the usual entrance examination. Yemei had dreamed of attending Beijing University since she was a little girl, and that’s the university she chose to attend when she retired from professional competitions.展开更多
基金Supported by the National Basic Research Program of China(2007CB407204)~~
文摘Ridge tillage, which is a very common and important tillage measure in the black soil area of northeast China, has some soil and water conservation bene- fits, but has little attention. It is very important to explore the spatial distribution of the ridge direction of the arable land and its soil and water conservation benefits in different terrain conditions in the black soil area. So Binxian County of Heilongjiang Province was selected as the study area, and 168 field investigation units were ex- tracted by stratified sampling method and investigated. According to equations of slope gradient factor and slope gradient in ridge direction, and based on the soft- ware of Arcmap, SPSS and Excel, the investigation data of soil and water loss in Binxian County were analyzed and counted, The results show that in plain, hilly and mountainous areas, the average ground slope gradients are 1.92°, 6.20° and 8.27° respectively, and the average slope gradients along ridge direction are 1.33°, 4.52°and 6.45° respectively, which account for about 70%, 73% and 78% of the average ground slope gradients in the same terrain condition; the relative quantities of soil erosion in the present ridge tillage condition account for about 55%, 69% and 67% respectively of that in down-slope ridge tillage conditions, so the present ridge tillage has obviously relative soil and water conservation benefits. Based on these results, the reasons of the present ridge tillage status were analyzed, and some reform measures were proposed. The results could not only help to comprehend the spatial distribution and soil and water conservation benefits of ridge tillage in the black soil area of Northeast China, but also provide scientific references for the layout of local soil and water conservation measures.
文摘TWENTY years ago, while working in the rich black soil of the northeast, I came to know a Mr. Li. He was the blacksmith with the production team I worked on, the Heilongjiang Production & Construction Corps.His daughter, Li Yemei, is now a student at Beijing University. She had been admitted to China’s most famous university because of her outstanding achievements in sports. A marathon runner, she had won 13 championships in national and international competitions. In China, any athlete who has broken a world record or performed outstandingly in any of the three most important international events—the Olympic Games, the World Championships, or the World Cup—is given access to a university education without taking the usual entrance examination. Yemei had dreamed of attending Beijing University since she was a little girl, and that’s the university she chose to attend when she retired from professional competitions.
