We made comparative studies of three tropical ox-bow lakes in India with different trophic states.The species number of zooplanktons was negatively correlated with the degree of water eutrophication,and lakes of simil...We made comparative studies of three tropical ox-bow lakes in India with different trophic states.The species number of zooplanktons was negatively correlated with the degree of water eutrophication,and lakes of similar trophic status had higher similarity of species.The most significant differences of species composition were observed with rotifers and zoobenthos.The density and biomass of phytoplankton,rotifers,oligochaetes and chironomids tended to increase with increasing nutrients.We observed a significant difference of dominant species in different waters,especially the eutrophic lake,which was dominated by a few species of oligochaetes.The abundance of Tanypus bilobatus showed a highly significant correlation with the degree of eutrophication.Rotifers and zoobenthos showed considerably lower biodiversity in the eutrophic lake.展开更多
The arsenic contamination in soil-water-plant systems is a major concern of where, the groundwater is being contaminated with arsenic （above 0.01 mg/L） in the Indian subcontinent. The study was conducted with organi...The arsenic contamination in soil-water-plant systems is a major concern of where, the groundwater is being contaminated with arsenic （above 0.01 mg/L） in the Indian subcontinent. The study was conducted with organic matter to find out the reducing effect on arsenic load to rice （cv. Khitish）. It was observed that intermittent ponding reduced arsenic uptake （23.33% in root, 13.84% in shoot and 19.84% in leaf） at panicle initiation stage, instead of continuous ponding. A decreasing trend of arsenic accumulation （root straw husk whole grain milled grain） was observed in different plant parts at harvest. Combined applications of lathyrus ＋ vermicompost ＋ poultry manure reduced arsenic transport in plant parts （root, straw, husk, whole grains and milled grain） which was significantly at par （p 0.05） with chopped rice straw （5 tons/ha ） ＋ lathyrus green manuring （5 tons/ha） in comparison to control and corresponding soils. A significant negative correlation of arsenic with phosphorus （grain P with arsenic in different parts R 2 = 0.627–0.726 at p 0.01） was observed. Similarly, soil arsenic had a negative correlation with soil available phosphorus （R 2 = 0.822 at p 0.001） followed by soil nitrogen （R 2 = 0.762 at p 0.01） and soil potassium （R 2 = 0.626 at p 0.01）. Hence, effective management of contaminated irrigation water along with organic matter could reduce the arsenic build up to plants and soil.展开更多
文摘We made comparative studies of three tropical ox-bow lakes in India with different trophic states.The species number of zooplanktons was negatively correlated with the degree of water eutrophication,and lakes of similar trophic status had higher similarity of species.The most significant differences of species composition were observed with rotifers and zoobenthos.The density and biomass of phytoplankton,rotifers,oligochaetes and chironomids tended to increase with increasing nutrients.We observed a significant difference of dominant species in different waters,especially the eutrophic lake,which was dominated by a few species of oligochaetes.The abundance of Tanypus bilobatus showed a highly significant correlation with the degree of eutrophication.Rotifers and zoobenthos showed considerably lower biodiversity in the eutrophic lake.
基金supported by the National Agricultural Innovation Project Component-IV(NAIP/C4/C1005/2006-07),Indian Council of Agricultural Research,Pusa,New Delhi,India
文摘The arsenic contamination in soil-water-plant systems is a major concern of where, the groundwater is being contaminated with arsenic （above 0.01 mg/L） in the Indian subcontinent. The study was conducted with organic matter to find out the reducing effect on arsenic load to rice （cv. Khitish）. It was observed that intermittent ponding reduced arsenic uptake （23.33% in root, 13.84% in shoot and 19.84% in leaf） at panicle initiation stage, instead of continuous ponding. A decreasing trend of arsenic accumulation （root straw husk whole grain milled grain） was observed in different plant parts at harvest. Combined applications of lathyrus ＋ vermicompost ＋ poultry manure reduced arsenic transport in plant parts （root, straw, husk, whole grains and milled grain） which was significantly at par （p 0.05） with chopped rice straw （5 tons/ha ） ＋ lathyrus green manuring （5 tons/ha） in comparison to control and corresponding soils. A significant negative correlation of arsenic with phosphorus （grain P with arsenic in different parts R 2 = 0.627–0.726 at p 0.01） was observed. Similarly, soil arsenic had a negative correlation with soil available phosphorus （R 2 = 0.822 at p 0.001） followed by soil nitrogen （R 2 = 0.762 at p 0.01） and soil potassium （R 2 = 0.626 at p 0.01）. Hence, effective management of contaminated irrigation water along with organic matter could reduce the arsenic build up to plants and soil.
