Mixtures of phosphorus sources of different solubilities and uptake efficiency in corn intercropped with cover crops

Abstract

Tropical soils have chemical characteristics that promote the fixation of Phosphorus, causing phosphate fertilizers to have low uptake efficiency. The present work aimed to evaluate the efficiency of phosphate fertilization in corn crops with different crop systems, different sources of P and their mixtures. A completely randomized design with subdivided plots was adopted. The plots were formed of three treatments (corn cultivation systems): corn crop alone, corn intercropped with Crotalaria juncea, and corn intercropped with pigeon pea (Cajanus cajan). The subplots were formed of five treatments, created with two P sources and three mixtures between them, as follows: T1: 100% soluble phosphate (SP); T2: 75% SP –25% partially acidulated phosphate rock (PAPR); T3: 50% SP –50% PAPR; T4: 25% SP –75% PAPR; T5: 100% PAPR. The consortium with the pigeon pea and the crotalaria species reduced the productivity regardless of the source or mixture of sources used. The consortium cultivation, however, made a better use of the applied fertilizer, which means it can be a tool for improving levels of P uptake in the Brazilian agriculture.