Paper Title
Ecological Recovery of Soil Quality Through Intercropping Based on Rubber Agroforestry Systems

Abstract
Intercropping species in agroforestry systems are known to enhance yield and nutrient acquisition. However, studies that examine modification in soil quality due to intercropping compared to monoculture remains limited. Xishuangbanna prefecture, Yunnan province, China, has a vast land area under rubber monoculture plantations, leading to degradation of soil quality of the region. For the assessment of intercropping systems in improving the soil quality in rubber plantations, we established an experiment in Xishuangbanna, Yunnan Province, southwest China. Along with rubber monoculture (R) plantation, we selected five different intercropping systems in the study region, where rubber was intercropped separately with five vegetation species, viz., tea (Camellia sinensis) (RT), cacao (Theobroma cacao) (RC), bauhinia (Bauhinia touranensis) (RB), tea and mandarin orange (Citrus reticulata) (RTO), and flemingia (Flemingia macrophylla) (RF). We also evaluated associated contribution of intercrops to litter generation. The ordination test indicated that all intercropping types had significantly different soil quality compared to R. Percentage variation was highest for axis 1 (37%) as compared to axis 2 (5%). We found that the soil acidity was reduced due to intercropping, while total carbon, total nitrogen and available nitrogen registered higher values in majority of intercropping systems, except the value in RT. The stepwise regression model suggested that the most influential factors for the abundance of fauna include available potassium, available nitrogen and total nitrogen. Moreover, the litter input in intercropping was generally greater than the rubber monoculture. Our study suggests that government and associated agricultural bodies should adopt the use of Cacao, Bauhinia, Flemingia and Tea-Orange as intercrops for rubber in order to improve the overall quality of soil in China. Keywords - Intercropping, Litter Fauna, Rubber Monoculture, Soil Properties