Intercropping Wolfberry with Gramineae plants improves productivity and soil quality

Abstract The intercropping of shrubs with Gramineae species has been used widely to increase productivity and sustainability in modern agriculture. However, there have been few studies of intercropping of Wolfberry shrubs (Lycium barbarum) and it is cultivated mostly by clean tillage. In this study, we measured land productivity, crop yield and quality, and soil properties when L. barbarum was intercropped with Gramineae plants compared to when grown in a monoculture with clean tillage. The results showed that Wolfberry/ Gramineae intercropping improved productivity and fruit quality as evidenced by a significant increase in the Land Equivalent Ratio (LER) and the content in the fruit of carotenoid, flavonoid, total sugar and ascorbic acid. The nutrient content and enzyme activity of rhizosphere soils were higher under intercropping. The physical properties of the soil also improved with increased soil moisture, available potassium, available phosphorus and total nitrogen. The effect of intercropping on bacterial diversity was greater than that on fungal diversity, especially alpha diversity as shown by the Shannon Index, although both groups were markedly altered by intercropping. Binding spatial ordination analysis demonstrated that potassium and nitrogen were the nutrients that most affected the bacterial community, and all soil enzymes corelated with bacterial community composition. Collectively, these results suggest that intercropping of L. barbarum with Gramineae plants alters the soil bacterial community composition which reflects changes in soil properties and enzyme activities. Our findings show how to improve Wolfberry productivity and they provide insights into the mechanisms underlying healthy, biodiverse soils in agroecosystems.