The experiment was conducted to study the impact of application of microbial inoculants, compared with no microbial fertilizer, on enzyme activity, microbial biomass and available nutrient contents in paddy soil in He...The experiment was conducted to study the impact of application of microbial inoculants, compared with no microbial fertilizer, on enzyme activity, microbial biomass and available nutrient contents in paddy soil in Heilongjiang Province. The application of soil phosphorus activator was able to increase the quantity of bacteria and fungi in soil, but its effect on actinomycetes in soil was not significant. The application of microbial inoculants increased the urease and sucrase activities in soil over the growing season, but only at the maturing stage soil acid phosphatase activity was enhanced with the applying soil phosphorus activator. The application of soil phosphorus activator increased alkali-hydrolyzable nitrogen and available phosphorus contents in soil, but did not increase available potassium content in soil. The optimal microbial inoculant application rate as applied as soil phosphorus activator was 7.5 kg hm-2.展开更多
Root C and root-released C are closely related to soil organic matter content and mechanistic simulation modeling has proven to be useful for studying root and soil organic C dynamics in plant-soil ecosystems. A compu...Root C and root-released C are closely related to soil organic matter content and mechanistic simulation modeling has proven to be useful for studying root and soil organic C dynamics in plant-soil ecosystems. A computer model was designed in this study to simulate the dynamics of root C and root released C decomposition in situ and the dynamics of different forms of C in soil under two barley cultivars （Abee and Samson）. The results showed that on the 15th day, about 48% of the total 14C fixed in roots was respired for Abee and 42% for Samson. This indicated that the turnover rate of root ^14C of Abee was higher than that of Samson. The percentage of water-soluble organic ^14C, active microbial ^14C and stable ^14C over the total fixed ^14C were not different between two barley cultivars. From the analysis of the model for two barley cultivars, the total ~4C transformed into different soil pools （excluding CO：-C and root C pools） for the two barley cultivars was similar （26% for Abee and 25% for Samson）, but the difference of ^14C remaining in soil between the two barley cultivars was mainly because of the difference of ^14C remaining in roots which have not been yet decomposed. Some of the information which could not be measured in the laboratory conditions was obtained in this studv.展开更多
文摘The experiment was conducted to study the impact of application of microbial inoculants, compared with no microbial fertilizer, on enzyme activity, microbial biomass and available nutrient contents in paddy soil in Heilongjiang Province. The application of soil phosphorus activator was able to increase the quantity of bacteria and fungi in soil, but its effect on actinomycetes in soil was not significant. The application of microbial inoculants increased the urease and sucrase activities in soil over the growing season, but only at the maturing stage soil acid phosphatase activity was enhanced with the applying soil phosphorus activator. The application of soil phosphorus activator increased alkali-hydrolyzable nitrogen and available phosphorus contents in soil, but did not increase available potassium content in soil. The optimal microbial inoculant application rate as applied as soil phosphorus activator was 7.5 kg hm-2.
文摘Root C and root-released C are closely related to soil organic matter content and mechanistic simulation modeling has proven to be useful for studying root and soil organic C dynamics in plant-soil ecosystems. A computer model was designed in this study to simulate the dynamics of root C and root released C decomposition in situ and the dynamics of different forms of C in soil under two barley cultivars （Abee and Samson）. The results showed that on the 15th day, about 48% of the total 14C fixed in roots was respired for Abee and 42% for Samson. This indicated that the turnover rate of root ^14C of Abee was higher than that of Samson. The percentage of water-soluble organic ^14C, active microbial ^14C and stable ^14C over the total fixed ^14C were not different between two barley cultivars. From the analysis of the model for two barley cultivars, the total ~4C transformed into different soil pools （excluding CO：-C and root C pools） for the two barley cultivars was similar （26% for Abee and 25% for Samson）, but the difference of ^14C remaining in soil between the two barley cultivars was mainly because of the difference of ^14C remaining in roots which have not been yet decomposed. Some of the information which could not be measured in the laboratory conditions was obtained in this studv.
