The Monthly Dynamic Of Soil Quality Of Toona Sinensis Plantation In South Of Sichuan Area

Soil quality is crucial to the health of animal and plant and human, it related to the sustainability of resources and environment, affects the country’s food security. With the rapid economic development and population growth, soil degradation and soil erosion worsening, soil quality has become a hot soil science research. Returning farmland to forest and Low-function forest transformation are important projects of the people’s livelihood for the serious soil erosion region, the soil quality evolution of returning farmland to forest and low- function forest transformation can provide a theory basis and technical advice for the smooth progress of the two projects. Contrasted with Cryptomeria fortune and Cupressus funebris artificial forest and wasteland, the lunar dynamic changes of soil physical, chemical and biological properties (including soil microorganisms and enzyme activities) on Toona sinensiss plantation of different planting age in Xinwen county were studied. The results showed:(1) Toona sinensiss plantation soil bulk density and pH value adverse with increasing planting age, age 4 years to 9 years decreased 5.70% and 2.21%; With the increment of soil depth, soil bulk density of different forest land and wasteland increased gradually. The difference of forestry land and wasteland soil bulk density and pH value change with different months was not significant.(2) The soil porosity, water holding capacity and water storage of Toona sinensiss plantation increased with increasing planting age, the soil non-capillary porosity in the sharpest increase from age 4 to 9 years, reaching 35.89%; with the increment of soil depth, the soil porosity, water holding capacity and water storage decreased in different forest land and wasteland; with different months, the difference of forestry land and wasteland soil non-capillary porosity, water holding capacity and water storage was significant, the soil capillary porosity and total porosity difference were not significant.(3) Toona sinensiss plantation soil organic matter, total nitrogen, total phosphorus, total potassium, alkalized-N, available phosphorus and potassium increased with increasing planting age; the soil organic matter and nutrients in different forest land and wasteland decreased with the increment of soil depth. Analysis of soil nutrients in different months, Cupressus funebris plantation soil organic matter and alkalized-N higher than other forest land and wasteland, the hightest of the soil nitrogen, total phosphorus, total potassium, available phosphorus and potassium was the age of 9 years Toona sinensiss plantation.(4) The number of soil bacteria, fungi, actinomycetes and total microbial in different forest land and wasteland decreased with the increment of soil depth, where the number of bacteria has the maximum contribution rate to total microbial; the number of all three strains and microbial amount increased with increasing planting age of Toona sinensiss,9 years increased 65.77% than 4 years; with the seasons change, the number of soil fungi, actinomycetes and total microbial in Toona sinensiss plantation were maximum during summer, the soil bacteria number was maximum in the fall; Cupressus funebris, Cupressus Junebris plantation and wasteland soil bacteria ctinomycetes and total microbial numbers were maximum in summer, the number of soil fungi was maximum in the fall.(5) The soil enzyme activities expressed as 9 years Toona sinensiss plantation,7 years Toona sinensiss plantation, Cupressus funebris plantation, Cryptomeria fortune plantation, 4 years Toona sinensiss plantation and wasteland; With the increment of soil depth, the soil catalase, urease and invertase activities in the vertical distribution trend of forest land and wasteland weakened; the highest of the soil catalase and urease activities were in the autumn in Toona sinensiss and Cryptomeria fortune plantation, were in the summer in Cupressus funebris plantation; the peak of the wasteland soil catalase activity was in summer, the soil urease activity was in spring; all of the forest land and wasteland soil invertase higher in spring and autumn, lower in summer and winter.In summary, the planted of Toona sinensiss plantation improved the soil quality, effectively improved the soil hydrological properties, soil nutrient status, increased the number of soil microbial and regulation of enzyme activity, the effect of the improvement is more prominent with increasing planting age.