Index Screening And Evaluation Of Soil Fertility Quality Of Eucalyptus Plantation

Eucalyptus has been planted continuously and singly in large areas and high intensity in southern China,which has an impact on soil fertility quality and the environment,and has aroused widespread concern in society.This research carried out the screening and evaluation of the soil fertility quality index of Eucalyptus plantation,which aim to select suitable Eucalyptus in the woodland,maintain and improve soil fertility and promote the planning of Eucalyptus plantation.This paper established 90 standard Eucalyptus plantations in the main Eucalyptus production areas,and measured 33 soil fertility quality indicators including soil physical properties,chemical properties,and biological properties;using principal component analysis,correlation analysis,redundancy analysis,cluster analysis and other statistical analysis methods;using average soil fertility quality index(SQIa),weighted soil fertility quality index(SQIw),Nemoro quality index(SQIn),grey correlation degree(SQIg)to evaluate soil fertility quality;There are three types of data sets:total data set(TDS),minimum data set(MDS),and revised minimum data set(RMDS)to evaluate and verify the soil fertility quality of Eucalyptus plantations.The main conclusions are as follows:(1)10 soil fertility quality indicators were selected as the minimum data set of Eucalyptus plantations.The soil fertility quality indicators included in MDS are:soil bulk density,soil quality water content,soil aeration,pH,total nitrogen,available phosphorus,available iron,available zinc,ammonia nitrogen,and invertase,including 3 physical indicators and chemical indicators 6 and 1 biological index.At the same time,13 soil fertility quality indicators were screened as the minimum data set revised for Eucalyptus plantations.The RMDS indicators include:capillary pores,soil aeration,soil bulk density,pH,organic matter,available copper,total potassium,available boron,and available iron,invertase,microbial biomass phosphorus,catalase,microbial biomass carbon,including 3 physical indicators,6 chemical indicators,and 4 biological indicators.(2)Use linear regression analysis and correlation analysis to verify that MDS and RMDS are significantly correlated.RMDS is more accurate and effective than MDS.(3)Redundancy analysis shows that the physical and chemical properties of soil have an impact on biological properties.Total potassium,soil aeration,total nitrogen,available potassium,maximum water holding capacity,organic matter,nitrate nitrogen,non-capillary pores,capillary water holding capacity,ammonia nitrogen,available zinc,total porosity,minimum water holding capacity,effective magnesium,capillary Porosity,available calcium,total phosphorus,pH,and available copper are all indicators of physical and chemical properties that are more sensitive to biological properties.Available boron,soil mass water content,available phosphorus,available iron,soil volumetric water content,soil bulk density,and available manganese are all indicators that are relatively insensitive to biological properties in physical and chemical properties.(4)This study used a variety of methods to evaluate the soil fertility quality and found that the overall soil fertility quality of Eucalyptus plantations was not high.(5)Cluster analysis shows that the soil of Eucalyptus plantation can be divided into three levels,and the soil fertility quality index between each level of soil has significant differences.The order of soil fertility quality index from large to small is:third level>second level>first level.One-way analysis of variance showed that the third-level maximum water holding capacity,minimum water holding capacity,capillary water holding capacity,soil mass water content,non-capillary pores,soil aeration,organic matter,available iron,nitrate nitrogen,invertase,urease,acid phosphatas and catalase are significantly higher than the first level soil and the second level soil.(6)The study found that the total phosphorus and available manganese content of the Eucalyptus plantation soil were low,and the available phosphorus,available potassium,available copper,and available boron were lower than 10 mg/kg,100 mg/kg,2 mg/kg,0.5 mg/kg,respectively,so we should pay attention to the supplement of phosphorus,potassium,copper,and boron in the process of soil management and fertilization in Eucalyptus plantations in the future.