Plant Components of Agroforestry System Have Different Contributions to Soil Fertility

The objective was to evaluate soil fertility in agrosilvopastoral system in an area influenced by plant components. The study was carried out in the semi-arid region, in the municipality of Sobral (Ceará State, Brazil). The studied treatments were three plant components: shrub (Leucaena leucocephala), tree (Poincianera pyramidalis), crop (Zea mays) and an area of natural regeneration, all at four soil depths. The main chemical attributes were evaluated in the soil samples. The plant components contribute differently to the chemical attributes, especially the tree component, promoting improvements even without the addition of inputs.