Agronomic efficiency of rock phosphates used alone or associated with soluble source of phosphorus for corn and common bean crops cultivated in succession under no-tillage and irrigated system.

• Autor(a) principal: COELHO, A. M.
• Data de Publicação: 2023
• Outros Autores: RESENDE, A. V. de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Texto Completo: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1159066; http://doi.org/10.22533/at.ed.9733182309111
• topic: Fosfato; Fósforo; Milho; Feijão; Plantio Direto

Tropical soils present a high adsorption capacity in the dynamics of the applied P, thus reducing their initial efficiency of use by the plants. Within this approach, sources of P with lower solubility, such as natural rock phosphates with different degrees of reactivity (slow release), could be an alternative for fertilization of these soils, in relation to soluble phosphates. In order to evaluate this possibility, experiments with maize and bean crops were conducted in Sete Lagoas-MG, in a “Latossolo Vermelho” (Oxisol) clayey texture. The experimental design was in a randomized block design, with four replications, with the treatments arranged in subplots, with phosphorus sources in the plots, and in the subplots the doses of P applied annually. The treatments consisted of phosphorus sources: Phosphorite (18 % P2 O5 total), Bayóvar (29 % P2 O5 total) and Triple Superphosphate (45 % P2 O5 total), broadcast applied and incorporated in soil 0-10 cm depth, at a dose of 200 kg of P2 O5 ha-1, calculated on basis of total P2 O5 content of the sources. A control treatment, without applying phosphate fertilization was included. As maintenance fertilization, for each source and control treatment, doses of 0, 50 and 100 kg of P2 O5 ha-1, applied annually in the furrow at sowing time of corn, in the form of Triple Superphosphate. The corn was sowing in the spring/summer in six successive crops in the period 2012 to 2018. The bean was sowing in the autumn/winter, in four successive crops, in the period of 2013 to 2016. The initial application of a high dose of P as a corrective fertilizer, using sources varying in reactivity, was ineffective in terms of increasing the productivity of corn and beans, both for immediate and residual effect, when compared to the annual application of doses of P as maintenance fertilizer. The highest grain yields obtained with the annual application of 100 kg of P2 O5 ha-1 as Triple Superphosphate.