A special kind of rice field exists in China that is flooded year-round. These rice fields have substantially large CH4 emissions during the rice-growing season and emit CH4 continuously in the non-rice growing season...A special kind of rice field exists in China that is flooded year-round. These rice fields have substantially large CH4 emissions during the rice-growing season and emit CH4 continuously in the non-rice growing season. CH4 emission factors were used to estimate the CH4 emissions from year-round flooded rice fields during the rice-growing season in China. The CH4 emissions for the year-round flooded rice fields in China for the rice growing season over a total area of 2.66 Mha were estimated to be 2.44 Tg CH…展开更多
Over-use of fertilizer in paddy fields could lead to agro-environmental pollution. Therefore, the Paddy Fertilizer Recommendation System (PFRS) application package was designed to aid in the dissemination of fertilize...Over-use of fertilizer in paddy fields could lead to agro-environmental pollution. Therefore, the Paddy Fertilizer Recommendation System (PFRS) application package was designed to aid in the dissemination of fertilizer recommendations for paddy fields. PFRS utilized geographical information system (GIS) ActiveX Controls, enabling the user to select a location of interest linked to a spatial database of paddy field soil characteristics. The application package also incorporated different soil fertilizer recommendation methods, forming a relational database. The application's structure consisted primarily of building database queries using Standard Query Language (SQL) constructed during run-time, based on user provided spatial parameters of a selected location, the type of soil desired and paddy production criteria. PFRS, which was comprised of five modules including: File, View, Edit, Layer and Fertilizer/Model, provided the user with map-based fertilizer recommendations based on selected soil nutrient P and K map layers as well as N characteristics and land use maps.展开更多
The Sanjiang Plain, formed with confluence of the Amur River, Ussuri River and Songhua River, is one of the three major stretches of wetland in the world. The large-scale agricultural development on the Sanjiang Plain...The Sanjiang Plain, formed with confluence of the Amur River, Ussuri River and Songhua River, is one of the three major stretches of wetland in the world. The large-scale agricultural development on the Sanjiang Plain started at the end of the 40s of the 20th century. The low-lying terrain and frequent floods caused a lot of difficulties to the agricultural development in the area. Water conservancy program has always been the kernel in agricultural development on the Sanjiang Plain in its history. The entities involved in its development project from different levels, including the state, state farms and farmers. Thus far, we have used the findings of their analysis of the paddy field development process at one state farm to take a microscopic approach to shed light on the development of paddy fields by farms and farmers and their roles in subsequent rice production. Because paddy field management on the Sanjiang Plain is very broad, but its rice producing techniques and economic structure have a certain definite form, the microscopic approach to understanding the paddy field development process and rice fanning management structure on the level of farmers could be considered a success. This paper is intended to elucidate from a macroscopic perspective the characteristics of the rapid development of irrigation and drainage systems and paddy fields on the Sanjiang Plain. Sanjiang Plain is a flood plain, and so major infrastructure development was required, thereby necessitating this national project for flood control. As politics and an economic integrated body, state farms also contributed to the promotion of agricultural development. As principals for the development, the state and state farms are taken by this paper as the main objects of our analysis.展开更多
This study aims to clarify the factors that form rice prices for different producing areas and brands in Japan, while ascertaining consumers＇ criteria in purchasing rice and their preference for taste in China, in or...This study aims to clarify the factors that form rice prices for different producing areas and brands in Japan, while ascertaining consumers＇ criteria in purchasing rice and their preference for taste in China, in order to establish the method to formulate an overseas marketing strategy for Japanese rice.展开更多
Rice straw is a rice by-product, which is currently mostly wasted in Vietnam, in particular in the Mekong delta. At present, the cost of straw gathering is increasing because of the increased use of combine harvesters...Rice straw is a rice by-product, which is currently mostly wasted in Vietnam, in particular in the Mekong delta. At present, the cost of straw gathering is increasing because of the increased use of combine harvesters. High labor cost and lack of labor makes manual collection unfeasible. Farmers therefore often just burn it, which causes pollution, increased greenhouse gas emissions and loss of opportunities to value add. An economic and environmental evaluation and technical field testing of a straw baler with 4 ha/day capacity was therefore conducted in Long An province. During the field testing data on the gathering capacity, fuel consumption, labor requirement and other cost items were collected. The test results showed that the baling cost is US$19.0 per ton of rice straw, the pay-back period of 2. 1 years and the internal rate of return of 38%. In addition to the baling cost, the transportation cost varies from US$24 for a distance of 100 km to US$32 for 150 km. The benefits of the machine are not only economical but also include the reduction of field burning.展开更多
Persistent organic pollutants （POPs） in soils are an environmental concern due to their long-term bioavailability, which could be reduced by adding adsorbents. However, testing of these adsorbents is necessary prior...Persistent organic pollutants （POPs） in soils are an environmental concern due to their long-term bioavailability, which could be reduced by adding adsorbents. However, testing of these adsorbents is necessary prior to widespread field application. The effects of three adsorbents, nano-organic montmorillonite, nano-organic silicon dioxide （SiOs）, and activated carbon, on hexachlorobenzene （HCB） and pentachlorobenzene （PeCB） accumulation in rice （Oryza sativa L.） plants were tested in a greenhouse experiment using two soils, a Hydragric Acrisol （Ac） and a Gleyi-Stagnic Anthrosol （An）. The bioconcentration factors （BCFs） of HCB and PeCB to rice roots were 2.3-3.7 and 2.0 3.0 times those to rice shoots, respectively. The applications of the three adsorbents decreased HCB and PeCB extractability in Ac, while only the application of activated carbon decreased their extractability in An. The bioavailability of HCB and PeCB to rice plants in Ac was higher than that in An. In Ac, the applications of nano-organic SiOs and activated carbon decreased the BCF of HCB to rice roots by 16.1% and 26.8%, respectively, whereas only the application of activated carbon decreased the BCF of PeCB to rice roots by 31.4%, compared to the control. In An, only the application of activated carbon decreased the BCFs of HCB and PeCB to rice roots by 22.9% and 18.2%, respectively, compared to the control. However, the application of nano-organic montmorillonite inhibited rice growth in both soils. The results of this study suggested that the effectiveness of adsorbents would vary with pollutant and soil types, providing a reference point for developing efficient adsorbents to reduce the ecological risk of POPs.展开更多
文摘A special kind of rice field exists in China that is flooded year-round. These rice fields have substantially large CH4 emissions during the rice-growing season and emit CH4 continuously in the non-rice growing season. CH4 emission factors were used to estimate the CH4 emissions from year-round flooded rice fields during the rice-growing season in China. The CH4 emissions for the year-round flooded rice fields in China for the rice growing season over a total area of 2.66 Mha were estimated to be 2.44 Tg CH…
基金Project supported by the National Natural Science Foundation of China (No. 40001008) the China-British Higher Education Links (No. SHA/992/297).
文摘Over-use of fertilizer in paddy fields could lead to agro-environmental pollution. Therefore, the Paddy Fertilizer Recommendation System (PFRS) application package was designed to aid in the dissemination of fertilizer recommendations for paddy fields. PFRS utilized geographical information system (GIS) ActiveX Controls, enabling the user to select a location of interest linked to a spatial database of paddy field soil characteristics. The application package also incorporated different soil fertilizer recommendation methods, forming a relational database. The application's structure consisted primarily of building database queries using Standard Query Language (SQL) constructed during run-time, based on user provided spatial parameters of a selected location, the type of soil desired and paddy production criteria. PFRS, which was comprised of five modules including: File, View, Edit, Layer and Fertilizer/Model, provided the user with map-based fertilizer recommendations based on selected soil nutrient P and K map layers as well as N characteristics and land use maps.
文摘The Sanjiang Plain, formed with confluence of the Amur River, Ussuri River and Songhua River, is one of the three major stretches of wetland in the world. The large-scale agricultural development on the Sanjiang Plain started at the end of the 40s of the 20th century. The low-lying terrain and frequent floods caused a lot of difficulties to the agricultural development in the area. Water conservancy program has always been the kernel in agricultural development on the Sanjiang Plain in its history. The entities involved in its development project from different levels, including the state, state farms and farmers. Thus far, we have used the findings of their analysis of the paddy field development process at one state farm to take a microscopic approach to shed light on the development of paddy fields by farms and farmers and their roles in subsequent rice production. Because paddy field management on the Sanjiang Plain is very broad, but its rice producing techniques and economic structure have a certain definite form, the microscopic approach to understanding the paddy field development process and rice fanning management structure on the level of farmers could be considered a success. This paper is intended to elucidate from a macroscopic perspective the characteristics of the rapid development of irrigation and drainage systems and paddy fields on the Sanjiang Plain. Sanjiang Plain is a flood plain, and so major infrastructure development was required, thereby necessitating this national project for flood control. As politics and an economic integrated body, state farms also contributed to the promotion of agricultural development. As principals for the development, the state and state farms are taken by this paper as the main objects of our analysis.
文摘This study aims to clarify the factors that form rice prices for different producing areas and brands in Japan, while ascertaining consumers＇ criteria in purchasing rice and their preference for taste in China, in order to establish the method to formulate an overseas marketing strategy for Japanese rice.
文摘Rice straw is a rice by-product, which is currently mostly wasted in Vietnam, in particular in the Mekong delta. At present, the cost of straw gathering is increasing because of the increased use of combine harvesters. High labor cost and lack of labor makes manual collection unfeasible. Farmers therefore often just burn it, which causes pollution, increased greenhouse gas emissions and loss of opportunities to value add. An economic and environmental evaluation and technical field testing of a straw baler with 4 ha/day capacity was therefore conducted in Long An province. During the field testing data on the gathering capacity, fuel consumption, labor requirement and other cost items were collected. The test results showed that the baling cost is US$19.0 per ton of rice straw, the pay-back period of 2. 1 years and the internal rate of return of 38%. In addition to the baling cost, the transportation cost varies from US$24 for a distance of 100 km to US$32 for 150 km. The benefits of the machine are not only economical but also include the reduction of field burning.
基金supported by the Open Fund Project of Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing University of Information Science and Technology, China (No. JKLAM1605)
文摘Persistent organic pollutants （POPs） in soils are an environmental concern due to their long-term bioavailability, which could be reduced by adding adsorbents. However, testing of these adsorbents is necessary prior to widespread field application. The effects of three adsorbents, nano-organic montmorillonite, nano-organic silicon dioxide （SiOs）, and activated carbon, on hexachlorobenzene （HCB） and pentachlorobenzene （PeCB） accumulation in rice （Oryza sativa L.） plants were tested in a greenhouse experiment using two soils, a Hydragric Acrisol （Ac） and a Gleyi-Stagnic Anthrosol （An）. The bioconcentration factors （BCFs） of HCB and PeCB to rice roots were 2.3-3.7 and 2.0 3.0 times those to rice shoots, respectively. The applications of the three adsorbents decreased HCB and PeCB extractability in Ac, while only the application of activated carbon decreased their extractability in An. The bioavailability of HCB and PeCB to rice plants in Ac was higher than that in An. In Ac, the applications of nano-organic SiOs and activated carbon decreased the BCF of HCB to rice roots by 16.1% and 26.8%, respectively, whereas only the application of activated carbon decreased the BCF of PeCB to rice roots by 31.4%, compared to the control. In An, only the application of activated carbon decreased the BCFs of HCB and PeCB to rice roots by 22.9% and 18.2%, respectively, compared to the control. However, the application of nano-organic montmorillonite inhibited rice growth in both soils. The results of this study suggested that the effectiveness of adsorbents would vary with pollutant and soil types, providing a reference point for developing efficient adsorbents to reduce the ecological risk of POPs.
