The morphology of the root system in five plant species can affect soil organic matter decomposition

Plants are affected by soil environments at the same extent they affect soil functioning through interactions between environmental and genetic factors. Here, five cultivated species (broad bean, pea, cabbage, fennel and olive) were grown under controlled pot conditions were tested for their ability of degrading standard litter (tea bags method) in the same soil type, under the same climatic conditions. Litter, soil C and N contents and soil microbial abundance were measured. The architecture and morphological traits of roots systems were also evaluated by using a specific open-source software (SmartRoot). Soil chemical and microbiological characteristics were significantly influenced by the cultivated plant species. Variations in soil C/N dynamics were correlated with the diversity of root traits among species. Early stage decomposition of the standard litter changed on the basis of the plant species. The results indicated that key soil processes are governed by interactions between plant roots, soil C and N, and the microbial metabolism that stimulate decomposition reactions. This, in turn, can have marked effects on soil nutrient cycling and soil fertility, both fundamental for sustaining crops, and promote the development of new approaches for optimizing soil C and N cycling, managing nutrient transport, and sustaining and improving net primary production.