Adopting A.pintoi as Live Mulch for Peach Orchards in China:Benefits of Soil and Water Conservation and Comprehensive Eco-service

Soil erosion occurred in orchards has often attracted extensive attentions from the society with environmental considerations,as orchard is one of major methods of agricultural production in China.In the hilly red soil region of China,many orchards are established on slope lands with a lack of grass covers,leading to severe soil losses.In order to mitigate this common environmental problem and evaluate the efficiency of erosion-control approaches,four treatments were set in field plots in this study,including terraced peach orchard with Arachis pintoi cv.Amarillo as mulch and Paspalum natatu and Digitariasmutsii as hedgerows(TTM),terraced peach orchard without conservation measures(TTW),sloping peach orchard with A.pintoi as mulch and P.natatu and Digitariasmutsii as hedgerows(STM),and sloping peach orchard without conservation measures(STW).The surface runoff,sediment yields and the contents of soil nutrients and organic carbon were monitored in the four treatments and the comprehensive eco-service benefits were further evaluated.The results indicate that available phosphorus(AP),available potassium(AK),total nitrogen(TN) and organic matter(OM) in the soils of the TTM treatments and STM were significantly higher than those of the treatments TTW and STW,suggesting positive effects of the vegetation covers on the soil nutrients.Mean annual surface runoff and coefficient ranged from 0.86 to 34.79 m~3,and 0.007 to 0.282,respectively;the treatment TTM exhibited the best water conservation benefits and the treatment STW was the worst.Soil erosion modulus of the plots were 0-28.76t/hm~2 per year in average,and the treatments TTM and STM reduced significantly soil loss in comparison of the treatments TTW and STW;(d) total organic carbon in the vegetation covers ranged from 130.23 to 195.93 kg per year,and that for TTM and STM treatment significantly higher than TTW and STW treatment;comprehensive eco-service values of the orchards were evaluated considering all the factors including water conservation,soil fertility conservation,CO_2 fixation and O_2 supply,ranging from 563.35 $/y to 765.51 $/y.As expected,the treatments TTM and STM had significantly greater eco-service values than the treatments TTW and STW.In summary,we concluded that terraced orchard with A.pintoi as live mulch plus Paspalum natatu and Digitariasmutsii as hedgerows is a highly sustainable land use practice for the slope lands in red soil hilly region of China.