The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Deli Chen - One of the best experts on this subject based on the ideXlab platform.
-
policy distortions farm size and the overuse of Agricultural Chemicals in china
Proceedings of the National Academy of Sciences of the United States of America, 2018Co-Authors: Yiyun Wu, Xican Xi, Xin Tang, Baojing Gu, Peter M Vitousek, Deli ChenAbstract:Understanding the reasons for overuse of Agricultural Chemicals is critical to the sustainable development of Chinese agriculture. Using a nationally representative rural household survey from China, we found that farm size is a strong factor that affects the use intensity of Agricultural Chemicals across farms in China. Statistically, a 1% increase in farm size is associated with a 0.3% and 0.5% decrease in fertilizer and pesticide use per hectare (P
Y Qi - One of the best experts on this subject based on the ideXlab platform.
-
effects of Agricultural Chemicals on dna sequence diversity of soil microbial community a study with rapd marker
Microbial Ecology, 2000Co-Authors: Yong-hua Yang, Shuijin Hu, Y QiAbstract:The DNA sequence diversities for microbial communities in four soils affected by Agricultural Chemicals (mainly triadimefon and ammonium bicarbonate and their intermediates) were evaluated by Random Amplified Polymorphic DNA (RAPD) analysis. Fourteen random primers were used to amplify RAPDs from four soil microbial community DNAs. The products of 12 primers were separated in gel and generated 155 reliable fragments, of which 134 were polymorphic. The richness, modified richness, Shannon–Weaver index, and a similarity coefficient of DNA were calculated to quantify the diversity to access DNA sequence diversities for four soil microbial communities. The results showed that Agricultural Chemicals affected soil microbial community diversity at the DNA level. The four soil microbial communities were distinguishable in terms of DNA sequence richness, modified richness, Shannon–Weaver index, and coefficient of DNA similarity. Analysis also showed that the amounts of organic C and microbial biomass C were low in the soil polluted by pesticide (mainly triadimefon and its intermediates), but high in the soil polluted by chemical fertilizer (mainly ammonium bicarbonate and its intermediates). The above results combined may indicate that pesticide pollution caused a decrease in the soil microbial biomass but kept high diversity at DNA level, compared with the control without chemical pollution. In contrast, chemical fertilizer pollution caused an increase in the soil biomass but decrease in the DNA diversity. The RAPD marker technique combined with analysis of soil microbial biomass appears to be an effective approach for studying the diversity of soil microbial communities, although the effects of PCR bias on community composition, such as dominating and rare populations in soils, on the diversity needed to be addressed further.
Yong-hua Yang - One of the best experts on this subject based on the ideXlab platform.
-
RAPD marker and substrate utilization pattern applied to study microbial community diversity in the soil affected by Agricultural Chemicals
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes, 2020Co-Authors: Yong-hua Yang, Meng-cheng WangAbstract:Present analyses of random amplified polymorphic DNA (RAPD) and Biolog GN substrate utilization pattern are combined to further study the diversity of microbial communities in four soils affected by Agricultural Chemicals. The results showed that the four soil microbial communities were apparently distinguishable in the diversity at RAPD level in terms of the richness and modified richness in the summer, which supports our previous report using the same soils in winter. A significant difference for the average well color development (AWCD) at 72 h incubation was found among the soils in winter using Biolog GN substrate utilization pattern, but this difference was not found among the soils in summer. However, Shannon-Weaver indices for microbial communities in the summer soils polluted by Agricultural Chemicals were significantly higher than those in winter at metabolic level; in contrast, no significant difference existed between the two seasons for microbial communities in the soil without chemical pollution. Present results suggest that the combined approach using RAPD and substrate utilization pattern could be used to effectively quantify microbial community diversity and its changes among the seasons in the soils affected by Agricultural Chemicals, simultaneously at molecular and physiological levels.
-
effects of Agricultural Chemicals on dna sequence diversity of soil microbial community a study with rapd marker
Microbial Ecology, 2000Co-Authors: Yong-hua Yang, Shuijin Hu, Y QiAbstract:The DNA sequence diversities for microbial communities in four soils affected by Agricultural Chemicals (mainly triadimefon and ammonium bicarbonate and their intermediates) were evaluated by Random Amplified Polymorphic DNA (RAPD) analysis. Fourteen random primers were used to amplify RAPDs from four soil microbial community DNAs. The products of 12 primers were separated in gel and generated 155 reliable fragments, of which 134 were polymorphic. The richness, modified richness, Shannon–Weaver index, and a similarity coefficient of DNA were calculated to quantify the diversity to access DNA sequence diversities for four soil microbial communities. The results showed that Agricultural Chemicals affected soil microbial community diversity at the DNA level. The four soil microbial communities were distinguishable in terms of DNA sequence richness, modified richness, Shannon–Weaver index, and coefficient of DNA similarity. Analysis also showed that the amounts of organic C and microbial biomass C were low in the soil polluted by pesticide (mainly triadimefon and its intermediates), but high in the soil polluted by chemical fertilizer (mainly ammonium bicarbonate and its intermediates). The above results combined may indicate that pesticide pollution caused a decrease in the soil microbial biomass but kept high diversity at DNA level, compared with the control without chemical pollution. In contrast, chemical fertilizer pollution caused an increase in the soil biomass but decrease in the DNA diversity. The RAPD marker technique combined with analysis of soil microbial biomass appears to be an effective approach for studying the diversity of soil microbial communities, although the effects of PCR bias on community composition, such as dominating and rare populations in soils, on the diversity needed to be addressed further.
Baojing Gu - One of the best experts on this subject based on the ideXlab platform.
-
policy distortions farm size and the overuse of Agricultural Chemicals in china
Proceedings of the National Academy of Sciences of the United States of America, 2018Co-Authors: Yiyun Wu, Xican Xi, Xin Tang, Baojing Gu, Peter M Vitousek, Deli ChenAbstract:Understanding the reasons for overuse of Agricultural Chemicals is critical to the sustainable development of Chinese agriculture. Using a nationally representative rural household survey from China, we found that farm size is a strong factor that affects the use intensity of Agricultural Chemicals across farms in China. Statistically, a 1% increase in farm size is associated with a 0.3% and 0.5% decrease in fertilizer and pesticide use per hectare (P
Jack E Barbash - One of the best experts on this subject based on the ideXlab platform.
-
national holistic watershed scale approach to understand the sources transport and fate of Agricultural Chemicals
Journal of Environmental Quality, 2008Co-Authors: Paul D Capel, Kathleen A Mccarthy, Jack E BarbashAbstract:: This paper is an introduction to the following series of papers that report on in-depth investigations that have been conducted at five Agricultural study areas across the United States in order to gain insights into how environmental processes and Agricultural practices interact to determine the transport and fate of Agricultural Chemicals in the environment. These are the first study areas in an ongoing national study. The study areas were selected, based on the combination of cropping patterns and hydrologic setting, as representative of nationally important Agricultural settings to form a basis for extrapolation to unstudied areas. The holistic, watershed-scale study design that involves multiple environmental compartments and that employs both field observations and simulation modeling is presented. This paper introduces the overall study design and presents an overview of the hydrology of the five study areas.
