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
This paper investigated effects of four ecological variables on the damage levels of elm leaf beetle （different effects of minimum and maximum values, relations between each two variables were also explored） and dis...This paper investigated effects of four ecological variables on the damage levels of elm leaf beetle （different effects of minimum and maximum values, relations between each two variables were also explored） and discussed current management measures. The results showed that among these factors, interval between elm trees significantly affected damage level by this leaf beetle species, and perimeter of elm trunk could change this effect. On the other side, while middle values for each index were deleted, effects comparison between minimum and maximum parts showed that good root soil as overwintering was related with more damage; more severe damages on elm tree would result in more control measures used; on elm tree with bigger mink, more damages were observed; and if other elm tree was closer, more damages would occur. Secondly, good root soil was related with more measures used; good root soil was correlated with smaller perimeter; good root soil was associated with bigger interval. Thirdly, more measures were correlated with bigger perimeter; more measures were also correlated with good root soil. Fourthly, bigger perimeter was correlated with worse root soil. Current dominant control measures included chemical pesticide application preventing adult insects from descending or climbing up along trunk before and after overwintering. These results suggested that we should focus on elm leaf beetle management on all the elm trees instead of only on bigger elm trees at proper period simultaneously because occurrence on these elm trees were related intensively although this adult elm leaf beetle species could not fly and had limited movement ability.展开更多
Plant uptake of contaminants provides vital information for the reclamation of large area of contaminated soils.A field experiment was conducted using four plant species growing in four kinds of oil contaminated soils...Plant uptake of contaminants provides vital information for the reclamation of large area of contaminated soils.A field experiment was conducted using four plant species growing in four kinds of oil contaminated soils to estimate the uptake of organic and inorganic contaminants by plants from the oil contaminated soils.The experiment showed that the concentrations of some selected elements,such as B,Co and Ni in plants growing in the oil contaminated soils were significantly higher than those in plants growing in the uncontaminated control soil.The accumulation of metals in plants increased with plant biomass;however,the removal of metals by plants from the oil contaminated soils was not practical.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.
基金Supported by SIPT of Northeast Agricultural University(201410224069)the National Natural Science Foundation of China(31100304)"Academic Backbone" Project of Northeast Agricultural University(15XG01)
文摘This paper investigated effects of four ecological variables on the damage levels of elm leaf beetle （different effects of minimum and maximum values, relations between each two variables were also explored） and discussed current management measures. The results showed that among these factors, interval between elm trees significantly affected damage level by this leaf beetle species, and perimeter of elm trunk could change this effect. On the other side, while middle values for each index were deleted, effects comparison between minimum and maximum parts showed that good root soil as overwintering was related with more damage; more severe damages on elm tree would result in more control measures used; on elm tree with bigger mink, more damages were observed; and if other elm tree was closer, more damages would occur. Secondly, good root soil was related with more measures used; good root soil was correlated with smaller perimeter; good root soil was associated with bigger interval. Thirdly, more measures were correlated with bigger perimeter; more measures were also correlated with good root soil. Fourthly, bigger perimeter was correlated with worse root soil. Current dominant control measures included chemical pesticide application preventing adult insects from descending or climbing up along trunk before and after overwintering. These results suggested that we should focus on elm leaf beetle management on all the elm trees instead of only on bigger elm trees at proper period simultaneously because occurrence on these elm trees were related intensively although this adult elm leaf beetle species could not fly and had limited movement ability.
文摘Plant uptake of contaminants provides vital information for the reclamation of large area of contaminated soils.A field experiment was conducted using four plant species growing in four kinds of oil contaminated soils to estimate the uptake of organic and inorganic contaminants by plants from the oil contaminated soils.The experiment showed that the concentrations of some selected elements,such as B,Co and Ni in plants growing in the oil contaminated soils were significantly higher than those in plants growing in the uncontaminated control soil.The accumulation of metals in plants increased with plant biomass;however,the removal of metals by plants from the oil contaminated soils was not practical.
