Phosphorus in oxisoils under corrective of soil acidity, phosphorus sources and cover crops

• Grant number: 17/10332-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2018
• End date: January 04, 2020
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Dirceu Maximino Fernandes
• Grantee: Luís Miguel Zittlau Pereira Brison
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Phosphorus is one of the main limiting problems to growth and production of agricultural crops in soils of tropical and subtropical regions. Considering that after silicate application, high C/N ratio of cover crops may provide waste decomposition synchronism and P liberation for the succession of crops, it is intended to investigate in two different soil types, the P availability for maize cultivated under Pennisetum americanum and Canavalia ensiformis straw, in greenhouse conditions. The research will be in plastic tunnel system in 10L capacity pot, in two experiments, one using and Rhodic Ferrasol and the other Rhodic Haplustox. The experiments are characterized like 3x3 factorial, composed by two cover crop species, non-plant treatment and three different phosphorus sources, in four repetitions, design with Random Block Design (RBD). These soils will remain 30 days in incubation after slag (S) and limestone (C) treatment 50% S + 50% C. After the incubation, cover crops will be sown, Pennisetum americanum and Canavalia ensiformis, in addition the references (without cover crop), which will be incorporated P sources: triple superphosphate (TSP), reactive phosphate and precipitated phosphate (industrial waste), in 300 mg dm-3, the other nutrients will be added by nutritive solution. The cover crops will be cultivated until pre-flowering, being cut and, partly intended to evaluation and the remainder replaced like cover crops in the pot. Over the Pennisetum americanum and Canavalia ensiformis straw, and without straw, the maize will be cultivated until the diagnosis leaves can be collected. In cover crops and maize will be evaluate morphologic measures, like plant height, stem diameter. In straw the P accumulation, fresh matter and dry matter mass will be evaluate. The soil will be analyzed chemically for fertility purposes. The data will be submitted to an analysis of variance ante the means compared using Tukey's test (5%). (AU)