紫色土丘陵恢复区不同土地利用方式土壤质量综合评价

Comprehensive Assessment of Soil Quality in Restoration Region of Hills with Purple Soils under Different Land-use Types

在紫色土丘陵恢复区,研究了撂荒地(AL)、紫穗槐-白花草木樨地(AML)、沙地柏+马桑地(SCL)、坡耕地(SFL)和马尾松林地(PFL)5种土地利用方式对0~20 cm土层土壤性质的影响。结果显示:AML与SFL的土壤pH和土壤体积质量显著低于其他土地利用方式,而土壤含水量、土壤有机碳、全氮、碱解氮和速效磷含量显著高于其他土地利用方式。不同土地利用方式的PLFA总量、细菌数量、真菌数量和放线菌数量、脲酶活性、蔗糖酶活性和酸性磷酸酶活性的大小为AML(或SFL)>SCL(或PFL)>AL(P<0.05),土壤微生物量碳和土壤微生物量氮的大小为AML>SFL>SCL(或PFL)>AL(P<0.05)。除速效钾外,土壤各因子间存在密切相关性。主成分分析评价的土壤肥力综合指数大小为AML(0.212)>SFL(0.209)>SCL(0.162)>PFL(0.147)>AL(-0.480)。研究表明AML和SFL(坡改梯+植物篱)最有利于恢复区土壤质量恢复,研究结果可为紫色土丘陵恢复区及相似条件地区的生态建设提供理论基础。

A study was conducted to analyze,compare and assess the soil quality of the 0-20 cm soil layers in restoration region of hills with purple soils in Hengyang,South-central China under different land-use types including AL(Abandoned land),AML(Amorpha fruticosa-Melilotus albus land),SCL(Sabina vulgaris+Coriaria nepalensis land),SFL(Slope farmland)and PFL(Pinus massoniana forest land)in 2021-2023.The results showed that:(1)Soil pH and soil bulk density(SBD)in AML and SFL were significantly lower than other land-use types(P<0.05),while contents of soil water content(SWC),soil organic carbon(SOC),total nitrogen(TN),alkali-hydrolyzable nitrogen(AN)and available phosphorus(AP)in AML and SFL were significantly higher than other land-use types(P<0.05);(2)Among different land-use types,the total phospholipid fatty acids(TPFAs),the number of bacteria(NBa),the number of fungi(NFu),the number of actinomycete(NAm),urease activity(UA),invertase activity(INA)and acid phosphatase activity(APA)were of the following sequence:AML(or SFL)>SCL(or PFL)>AL(P<0.05),the contents of soil microbial biomass carbon(SMBC)and soil microbial biomass nitrogen(SMBN)were of the following sequence:AML>SFL>SCL(or PFL)>AL(P<0.05);(3)There were close correlations among all soil factors apart from AK;(4)Integrated fertility index(IFI)of 0-20 cm soil layer in five land-use types by principal component analysis(PCA)were:AML(0.212)>SFL(0.209)>SCL(0.162)>PFL(0.147)>AL(-0.480).All the study showed that the AMI and SFL(changing slope into terrace+hedgerow)were the most beneficial land-use types for the recovery of soil quality in restoration region,and could provide theoretic basis for the ecological construction in restoration region on hills with purple soils and other areas with similar conditions.