The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw retur...The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw returning to the field,and the mechanism of the decomposition of rice straw returning to the field was discussed.Completely randomized experiment of the two factors of the three levels was designed,and a total of nine treatments of indoor soil incubation tests were conducted.Full amount of rice straw was applied to the soil in this simulation experiment and different amounts of brown sugar and urea were added in the three levels of 0(no carbon source and nitrogen source),1(low levels of carbon and nitrogen sources)and 2(high levels of carbon and nitrogen sources),respectively.The results showed that the addition of different amounts of carbon and nitrogen sources to the rice straw could increase the soil carbon content.Compared with T0N0,the microbial biomass carbon of T2N2 was increased significantly by 170.48%;the dissolved organic carbon content of T1N2 was significantly increased by 58.14%and the free humic acid carbon contents of T0N2,T1N1 and T2N0 were significantly increased by 56.16%and 45.55%and 47.80%,respectively;however,there were no significant differences among those of treatments at later incubation periods.The addition of different carbon and nitrogen sources could promote the soil enzyme activities.During the incubation period,all of the soil enzyme activities of adding sugar and urea were higher than those of T0N0 treatment.Therefore,the addition of different amounts of carbon and nitrogen sources to rice straw returning could improve soil microbial biomass carbon content,dissolved organic carbon and soil enzyme activities.展开更多
To explore the effects of the two chelating agents on the availability of calcium and phosphorus in black soil of vegetable fields and the growth of cabbage(Brassica pekinensis Rupr.)seedlings,humic acid(F)and ethylen...To explore the effects of the two chelating agents on the availability of calcium and phosphorus in black soil of vegetable fields and the growth of cabbage(Brassica pekinensis Rupr.)seedlings,humic acid(F)and ethylene diamine tetraacetic acid disodium salt(EDTA)were used as experiment materials,and two factors and three levels completely randomized experiment of the nine treatments was set.The experiments were carried out by soil incubation experiment and pot experiment to investigate the effects of the two chelating agents with different ratios and their interaction on soil and cabbage.The results showed that there were very significant differences among soil pH,soil available phosphorus content,cabbage biomass,calcium and phosphorus accumulation of cabbage under the interaction of the two chelating agents.It could improve pH of the soil and reduce the electric conductivity(EC)value of soil,when applied chelating agents of different proportions.The EC value of soil fluctuated during the incubation period.There were significant differences between pH and EC in the early incubation period,but there was no significant difference in the later stage.And there were significant differences between soil available calcium and available phosphorus content;there were significant differences between cabbage biomass and the accumulation of calcium and phosphorus in cabbage,and the data of F2E2 treatment were significantly higher than those of other treatments.In summary,under the conditions of the experiment,the available phosphorus content of black soil in vegetable fields,the biomass and accumulation of calcium and phosphorus in cabbage increased significantly in F2E2 treatment(appied 675 kg•hm-2 of lime,300 kg•hm-2 of humic acid and 150 kg•hm-2 of EDTA).展开更多
基金Supported by the National Key Research and Development Plan Project(2016YFD0300909-04)。
文摘The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw returning to the field,and the mechanism of the decomposition of rice straw returning to the field was discussed.Completely randomized experiment of the two factors of the three levels was designed,and a total of nine treatments of indoor soil incubation tests were conducted.Full amount of rice straw was applied to the soil in this simulation experiment and different amounts of brown sugar and urea were added in the three levels of 0(no carbon source and nitrogen source),1(low levels of carbon and nitrogen sources)and 2(high levels of carbon and nitrogen sources),respectively.The results showed that the addition of different amounts of carbon and nitrogen sources to the rice straw could increase the soil carbon content.Compared with T0N0,the microbial biomass carbon of T2N2 was increased significantly by 170.48%;the dissolved organic carbon content of T1N2 was significantly increased by 58.14%and the free humic acid carbon contents of T0N2,T1N1 and T2N0 were significantly increased by 56.16%and 45.55%and 47.80%,respectively;however,there were no significant differences among those of treatments at later incubation periods.The addition of different carbon and nitrogen sources could promote the soil enzyme activities.During the incubation period,all of the soil enzyme activities of adding sugar and urea were higher than those of T0N0 treatment.Therefore,the addition of different amounts of carbon and nitrogen sources to rice straw returning could improve soil microbial biomass carbon content,dissolved organic carbon and soil enzyme activities.
基金Supported by the Special Fund for Agro-scientific Research in Public Interest in China(201503119-06-01)。
文摘To explore the effects of the two chelating agents on the availability of calcium and phosphorus in black soil of vegetable fields and the growth of cabbage(Brassica pekinensis Rupr.)seedlings,humic acid(F)and ethylene diamine tetraacetic acid disodium salt(EDTA)were used as experiment materials,and two factors and three levels completely randomized experiment of the nine treatments was set.The experiments were carried out by soil incubation experiment and pot experiment to investigate the effects of the two chelating agents with different ratios and their interaction on soil and cabbage.The results showed that there were very significant differences among soil pH,soil available phosphorus content,cabbage biomass,calcium and phosphorus accumulation of cabbage under the interaction of the two chelating agents.It could improve pH of the soil and reduce the electric conductivity(EC)value of soil,when applied chelating agents of different proportions.The EC value of soil fluctuated during the incubation period.There were significant differences between pH and EC in the early incubation period,but there was no significant difference in the later stage.And there were significant differences between soil available calcium and available phosphorus content;there were significant differences between cabbage biomass and the accumulation of calcium and phosphorus in cabbage,and the data of F2E2 treatment were significantly higher than those of other treatments.In summary,under the conditions of the experiment,the available phosphorus content of black soil in vegetable fields,the biomass and accumulation of calcium and phosphorus in cabbage increased significantly in F2E2 treatment(appied 675 kg•hm-2 of lime,300 kg•hm-2 of humic acid and 150 kg•hm-2 of EDTA).
