Traditional agricultural systems have contributed to food and livelihood security. Rice-crab coculture （RC） is an important eco-agricultural process in rice production in northern China. Recognizing the soil fertili...Traditional agricultural systems have contributed to food and livelihood security. Rice-crab coculture （RC） is an important eco-agricultural process in rice production in northern China. Recognizing the soil fertility in RC may help develop novel sustainable agriculture. Soil carbohydrates are important factors in determining soil fertility in different culture modes. In this study, soil carbohydrates were analyzed under three different culture modes including rice monoculture （RM）, conventional rice-crab coculture （CRC） and organic rice-crab coculture （ORC）. Results showed that the contents of soil organic carbon and carbohydrates were significantly higher in the ORC than those in RM. The increasing effect was greater with increased organic manure. Similar tendency was found in CRC, but the overall effect was less pronounced compared with ORC. Carbohydrates were more Sensitive to RC mode and manure amendment than soil organic carbon. Compare to RM, the （Gal＋Man）/（Ara＋Xyl） ratio decreased in all the RC modes, indicating a relative enrichment in plant-derived carbohydrates due to the input of crab feed and manure. While the increasing （Gal＋Man）/（Ara＋Xyl） ratio in ORC modes with increased organic manure suggested that crab activity and metabolism induced microbially derived carbohydrates accumulation. The lower GluN/MurA ratio in ORC indicated an enhancement of bacteria contribution to SOM turnover in a short term. The findings reveal that the ORC mode could improve the quantity and composition of soil carbohydrates, effectively, to ensure a sustainable use of paddy soil.展开更多
Rice-crab integrated ecosystem has been confirmed to improve the ecological environment and brought greater economic benefits.In order to know greenhouse gases methane(CH_(4))and nitrous oxide(N_(2)O)emissions in rice...Rice-crab integrated ecosystem has been confirmed to improve the ecological environment and brought greater economic benefits.In order to know greenhouse gases methane(CH_(4))and nitrous oxide(N_(2)O)emissions in ricecrab system,they were quantified from a flooding rice field in northeast China,as affected by integrated ricecrab cultivation.Three treatments with three replications each were given:(1)RC1-rice with crab(megalopa),(2)RC2-rice with crab(juvenile),(3)RM-rice only.Seasonal CH_(4) and N_(2)O fluxes were measured by closed chamber method.Compared with RM treatment,RC1 and RC2 treatments greatly enhanced the cumulative seasonal CH_(4) emissions(by 36.8%and 29.2%,respectively),and reduced the cumulative seasonal N_(2)O emissions(by 28.2%and 19.7%,respectively).Across treatments,CH_(4) represented over 97%of total global warming potential(GWP)and as a result,RC1 and RC2 treatments significantly increased the GWP than RM treatment.Although the GWP was highest in RC1 treatment,it provided highest rice yield(8780 kg/ha)and net ecosystem economic budget(NEEB,23,159 Yuan/ha)over RM(7668 kg/ha,15,130 Yuan/ha)and RC2(8042 kg/ha,18,713 Yuan/ha)treatments.To summarize,cultivation of megalopa in rice field is a better strategy to optimize the economic and environmental benefits in northeast China.展开更多
基金supported by the National Natural Science Foundation of China (41101274 and 41101275)
文摘Traditional agricultural systems have contributed to food and livelihood security. Rice-crab coculture （RC） is an important eco-agricultural process in rice production in northern China. Recognizing the soil fertility in RC may help develop novel sustainable agriculture. Soil carbohydrates are important factors in determining soil fertility in different culture modes. In this study, soil carbohydrates were analyzed under three different culture modes including rice monoculture （RM）, conventional rice-crab coculture （CRC） and organic rice-crab coculture （ORC）. Results showed that the contents of soil organic carbon and carbohydrates were significantly higher in the ORC than those in RM. The increasing effect was greater with increased organic manure. Similar tendency was found in CRC, but the overall effect was less pronounced compared with ORC. Carbohydrates were more Sensitive to RC mode and manure amendment than soil organic carbon. Compare to RM, the （Gal＋Man）/（Ara＋Xyl） ratio decreased in all the RC modes, indicating a relative enrichment in plant-derived carbohydrates due to the input of crab feed and manure. While the increasing （Gal＋Man）/（Ara＋Xyl） ratio in ORC modes with increased organic manure suggested that crab activity and metabolism induced microbially derived carbohydrates accumulation. The lower GluN/MurA ratio in ORC indicated an enhancement of bacteria contribution to SOM turnover in a short term. The findings reveal that the ORC mode could improve the quantity and composition of soil carbohydrates, effectively, to ensure a sustainable use of paddy soil.
基金This work was supported by Agriculture Research System of Shanghai,China(Grant No.201804)Shanghai Leading Academic Discipline Project(No.Y1101)+1 种基金the AqASEM project(245020)under FP7The study was also supported by Shanghai Universities First-class Disciplines Project of Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding(No.ZF1206)。
文摘Rice-crab integrated ecosystem has been confirmed to improve the ecological environment and brought greater economic benefits.In order to know greenhouse gases methane(CH_(4))and nitrous oxide(N_(2)O)emissions in ricecrab system,they were quantified from a flooding rice field in northeast China,as affected by integrated ricecrab cultivation.Three treatments with three replications each were given:(1)RC1-rice with crab(megalopa),(2)RC2-rice with crab(juvenile),(3)RM-rice only.Seasonal CH_(4) and N_(2)O fluxes were measured by closed chamber method.Compared with RM treatment,RC1 and RC2 treatments greatly enhanced the cumulative seasonal CH_(4) emissions(by 36.8%and 29.2%,respectively),and reduced the cumulative seasonal N_(2)O emissions(by 28.2%and 19.7%,respectively).Across treatments,CH_(4) represented over 97%of total global warming potential(GWP)and as a result,RC1 and RC2 treatments significantly increased the GWP than RM treatment.Although the GWP was highest in RC1 treatment,it provided highest rice yield(8780 kg/ha)and net ecosystem economic budget(NEEB,23,159 Yuan/ha)over RM(7668 kg/ha,15,130 Yuan/ha)and RC2(8042 kg/ha,18,713 Yuan/ha)treatments.To summarize,cultivation of megalopa in rice field is a better strategy to optimize the economic and environmental benefits in northeast China.
