Paper mill sludge （PMS） is a kind of bio-solid waste. The technology of aerobic composting of PMS was investigated. The ratio of the material components was as follows, sludge：chicken dung：spill=6kg：2kg：4kg, whi...Paper mill sludge （PMS） is a kind of bio-solid waste. The technology of aerobic composting of PMS was investigated. The ratio of the material components was as follows, sludge：chicken dung：spill=6kg：2kg：4kg, which could attain 55% moisture content （MC） and 25 the ration of carbon to nitrogen （C/N）. The aeration rule of fan was controlled by single chip microcomputer （SCM）. During composting, the system temperature more than 55℃ lasted for 3 days, pH changed in the range of 6.5-8.5 and MC changed between 53% to 60%. PMS became mature on the 20th day. The germination index （GI） of compost attained 95% or so and coliform was 23/100 ml volatile solid （VS） and organic carbon （OC） were stable at the content of 60% and 30%, respectively. The result showed that this technology could make the sludge stable and innocuous. A pot experiment with latosolic red soil mixed with paper mill sludge compost （PMSC） was carried on. The result showed that PMSC could increase the crop biomass, the soil nutrients and the physical characteristics of the soil, such as OC, total nitrogen （TN）, total phosphorus （TP）. The total amount of heavy metals in the soil was measured to be lower than the Environmental standard for soil in China （GB15618-1995）. So PMSC was a good and safe soil amendment.展开更多
Farmers may not be conscious for their farmland＇s nutrients, soil organic matter, water and air because they simply concerned only for their labor availability and soil fertility losses. The composition and proportio...Farmers may not be conscious for their farmland＇s nutrients, soil organic matter, water and air because they simply concerned only for their labor availability and soil fertility losses. The composition and proportion of these components greatly influence soil physical properties, including texture, structure and porosity, the fraction of pore space in a soil. The soil of this farmland must be able to supply adequate amount of plant nutrients, in forms which can be absorbed by the crop, within its lifespan. Deficiencies or imbalances in the supply of any of essential elements can compromise growth, affecting root development, cell division, crop quality, crop yield and resistance to disease and drought. This study was conducted to fill this knowledge gap in order to develop economically vital and environmentally accepted nutrient management strategies for the use of soils in agricultural lands. The objective of this study is to assess the elemental contents and concentration of soil samples collected from farmlands of ＂Yebrage＂ using neutron activation analysis （NAA） techniques regardless of oxidation state, chemical form or physical locations. NAA is used to determine the elemental composition and concentrations present in a soil. The macro/micronutrient and organic matter deficiencies have been verified in agricultural soils through increased use of soil testing and plant analysis. The challenge for agriculture over the coming decades will meet the world＇s increasing demands for food in a sustainable way. Current issues and future challenges point out that as long as agriculture remains a soil based industry, major decreases in productivity likely to be attained ensuring that plants do not have adequate and balanced supply of nutrients.展开更多
Earthworms, one of the most important macroinvertebrates in terrestrial ecosystems of temperate zones, exert important influ- ences on soil functions. A laboratory microcosm study was conducted to evaluate the influen...Earthworms, one of the most important macroinvertebrates in terrestrial ecosystems of temperate zones, exert important influ- ences on soil functions. A laboratory microcosm study was conducted to evaluate the influence of the earthworm Eisenia fetida on wheat straw decomposition and nutrient cycling in an agricultural soil in a reclaimed salinity area of the North China Plain. Each microcosm was simulated by thoroughly mixing wheat straw into the soil and incubated for 120 d with earthworms added at 3 different densities as treatments： control with no earthworms, regular density （RD） with two earthworms, and increased density （ID） with six earthworms. The results showed that there was no depletion of carbon and nitrogen pools in the presence of the earthworms. Basal soil respiration rates and metabolic quotient increased with the increase in earthworm density during the initial and middle part of the incubation period. In contrast, concentrations of microbial biomass carbon and microbial biomass quotient decreased in the presence of earthworms. Earthworm activity stimulated the transfer of microbial biomass carbon to dissolved organic carbon and could lead to a smaller, but more metabolically active microbial biomass. Concentrations of inorganic nitrogen and NO^-N increased significantly with the increase in earthworm density at the end of the incubation （P ~ 0.05）, resulting in a large pool of inorganic nitrogen available for plant uptake. Cumulative net nitrogen mineralization rates were three times higher in the ID treatment than the RD treatment.展开更多
文摘Paper mill sludge （PMS） is a kind of bio-solid waste. The technology of aerobic composting of PMS was investigated. The ratio of the material components was as follows, sludge：chicken dung：spill=6kg：2kg：4kg, which could attain 55% moisture content （MC） and 25 the ration of carbon to nitrogen （C/N）. The aeration rule of fan was controlled by single chip microcomputer （SCM）. During composting, the system temperature more than 55℃ lasted for 3 days, pH changed in the range of 6.5-8.5 and MC changed between 53% to 60%. PMS became mature on the 20th day. The germination index （GI） of compost attained 95% or so and coliform was 23/100 ml volatile solid （VS） and organic carbon （OC） were stable at the content of 60% and 30%, respectively. The result showed that this technology could make the sludge stable and innocuous. A pot experiment with latosolic red soil mixed with paper mill sludge compost （PMSC） was carried on. The result showed that PMSC could increase the crop biomass, the soil nutrients and the physical characteristics of the soil, such as OC, total nitrogen （TN）, total phosphorus （TP）. The total amount of heavy metals in the soil was measured to be lower than the Environmental standard for soil in China （GB15618-1995）. So PMSC was a good and safe soil amendment.
文摘Farmers may not be conscious for their farmland＇s nutrients, soil organic matter, water and air because they simply concerned only for their labor availability and soil fertility losses. The composition and proportion of these components greatly influence soil physical properties, including texture, structure and porosity, the fraction of pore space in a soil. The soil of this farmland must be able to supply adequate amount of plant nutrients, in forms which can be absorbed by the crop, within its lifespan. Deficiencies or imbalances in the supply of any of essential elements can compromise growth, affecting root development, cell division, crop quality, crop yield and resistance to disease and drought. This study was conducted to fill this knowledge gap in order to develop economically vital and environmentally accepted nutrient management strategies for the use of soils in agricultural lands. The objective of this study is to assess the elemental contents and concentration of soil samples collected from farmlands of ＂Yebrage＂ using neutron activation analysis （NAA） techniques regardless of oxidation state, chemical form or physical locations. NAA is used to determine the elemental composition and concentrations present in a soil. The macro/micronutrient and organic matter deficiencies have been verified in agricultural soils through increased use of soil testing and plant analysis. The challenge for agriculture over the coming decades will meet the world＇s increasing demands for food in a sustainable way. Current issues and future challenges point out that as long as agriculture remains a soil based industry, major decreases in productivity likely to be attained ensuring that plants do not have adequate and balanced supply of nutrients.
基金the National Natural Science Foundation of China (No.31070454)the Program for Key Discipline of Ecology ofBeing City, China (No.XK10019440)
文摘Earthworms, one of the most important macroinvertebrates in terrestrial ecosystems of temperate zones, exert important influ- ences on soil functions. A laboratory microcosm study was conducted to evaluate the influence of the earthworm Eisenia fetida on wheat straw decomposition and nutrient cycling in an agricultural soil in a reclaimed salinity area of the North China Plain. Each microcosm was simulated by thoroughly mixing wheat straw into the soil and incubated for 120 d with earthworms added at 3 different densities as treatments： control with no earthworms, regular density （RD） with two earthworms, and increased density （ID） with six earthworms. The results showed that there was no depletion of carbon and nitrogen pools in the presence of the earthworms. Basal soil respiration rates and metabolic quotient increased with the increase in earthworm density during the initial and middle part of the incubation period. In contrast, concentrations of microbial biomass carbon and microbial biomass quotient decreased in the presence of earthworms. Earthworm activity stimulated the transfer of microbial biomass carbon to dissolved organic carbon and could lead to a smaller, but more metabolically active microbial biomass. Concentrations of inorganic nitrogen and NO^-N increased significantly with the increase in earthworm density at the end of the incubation （P ~ 0.05）, resulting in a large pool of inorganic nitrogen available for plant uptake. Cumulative net nitrogen mineralization rates were three times higher in the ID treatment than the RD treatment.
