Effect of Interplanting Caragana microphylla in Eucalyptusgrandis x E.urophylla Plantation on Soil Quality

Determinations were carried out on soil physio-chemical properties of different land use types, such as abandoned land （A）, pure 5-yearEucalyptus grandis × E. urophylla plantation（B）and E. grandis × E. urophylla interplanted with Caragana microphylla（C）in Fu’an, Fujian provincein 2017. Soil quality was evaluated by soil degradation index. The results showed that the soil bulk density at 0 - 30 cm soil layer of tested sampleplots was ordered by A> B> C, total porosity by C> B>A, pH, water content, organic carbon, total nitrogen, available nitrogen, available phosphorusand available potassium content by C >A >B. The SDI was C (0.167) > (0) >B(-0.13). The experiment concluded that pure E. grandis × E. urophyllaplantation had the worse soil quality in the tested 3 land types. Interplanting of C. microphylla could restore and improve soil quality.