Study On Soil Physical And Chemical Properties And Enzyme Activities Of Different Species Plantation In Southwest Guangxi

Soil is the material basis of plant growth,the soil physical and chemical properties and enzyme activities are the key indicators to evaluate soil quality.In order to reveal the influence of plantations on soil physical and chemical properties,in this study,12-year-old Pinus massoniana,hystrix,Mytilaria laosensis and 6-year-old Eucalyptus plantations(sprout plantation)as the research object,the soil physical properties,chemical properties and enzyme activities of four plantations were systematically studied.The main results showed that:(1)Four plantations soil bulk density and natural water content increased with soil depth increased,and the M.laosensis plantation in each soil layer thickness in the natural soil moisture content is the highest,the soil bulk density is the smallest,it can be concluded that M.laosensis plantation has better water permeability and the air permeability and strong water holding capacity.The total porosity,capillary porosity and non-capillary porosity of the four plantations decreased with the deepening of the soil layer.The rice-green plantation had good soil porosity and 0-20 cm soil(52.42%)>red vertebrate plantation(50.22%)>Eucalyptus plantation(49.47%)>Pinus massoniana plantation(48.19%).(2)With the soil depth increases,soil porosity of four plantations decreases;M.laosensis plantation has better soil porosity,total porosity of soil of different forest soil 0-20cm size for M.laosensis plantation(52.92%)>hystrix plantation(50.22%)>Eucalyptus Plantation(49.47%)>P.massoniana Plantation(48.19%);(3)With the soil depth increases,soil maxinmum moisture capacity,minimum moisture capacity,non capillary water capacity and field moisture capacity of four plantations decreases,soil maxinmum moisture capacity of 0-20cm is higher than 20-40cm,40-80cm high capacity;M.laosensis plantation in 0-20cm soil has good water-stable and its protection water is better performance than other plantations.(4)The determination results of four plantations soil extract pH(pH less than or equal to 4.6)showed that the 4 plantation soil was acidic,and the deeper soil,acidity decreases;the content of 4 kinds of soil organic matter,total nitrogen,hydrolyzable nitrogen,available phosphorus and available potassium are all decreased with soil layer deepening,the content of total phosphorus,total potassium with the deepening of soil thickness had no obvious change law;organic matter,total nitrogen and total potassium in soil were 0-20cm M.laosensis plantation was the highest;the total phosphorus and available phosphorus in 0-20cm or 20-40cm,40-80cm layers are Eucalyptus the plantation was the highest;the great demand of hystrix plantations on organic matter,total nitrogen,hydrolyzable nitrogen,total potassium,available potassium,because in each soil layer are ranked in the first or second;P.massoniana Plantations of various nutrient elements in different soil layers Content is not high,generally ranked third or fourth,ranked first or less in the second.The correlation analysis,the correlation between soil physical and chemical characters of the most significant physical and chemical properties,soil bulk density and some negative correlation(P<0.05)are;PH,organic matter and total nitrogen and the physicochemical properties showed a significant positive correlation(P<0.01);there is a certain correlation between other physical and chemical properties;(5)With the soil depth increases,the activities of catalase,protease,invertase,acid phosphatase,urease of 4 kinds plantation decreases;catalase,protease in 0-20cm and 20-40cm layer were the highest M.laosensis plantation;invertase of 0-20cm,20-40cm,40-80cm according to the strength of soil arrangement are hystrix plantation forest;Eucalyptus Plantation on masson pine plantation;the activity of acid phosphatase in different forest soil 0-20cm according to the strength of arrangement for the old meters plantation(0.849 mg · g-1)>hystrix plantation(0.783mg · g-1)>Eucalyptus Plantation(0.706mg · g-1)>P.massoniana plantation(0.677mg·g-1);soil urease activity was highest in M.laosensis plantation.The correlation between soil enzyme activity and soil physical and chemical properties was analyzed.The results showed that the soil enzyme activity was affected by the physical and chemical properties of soil nitrogen,soil bulk density,available phosphorus,organic matter and available phosphorus.