Release and efficiency of nitrogen use affected by anticipation of fertilization in forage for maize crop in succession

• Grant number: 17/19152-6
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): March 01, 2018
• Effective date (End): December 31, 2018
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Carlos Alexandre Costa Crusciol
• Grantee: Cassiano Silva Puoli
• Home Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

In a no - tillage system, annual crops seeded after growing forage grasses have gained importance in Brazil. In this system, new nitrogen fertilization management alternatives have emerged and farmers have applied all the nitrogen (N) in advance in the straw producing plant or on the straw before the sowing of annual crops. However, there are many doubts about the technical viability of this practice regarding the production, persistence and release of nutrients from the biomass, the availability of N in the soil and the yield increase of next crop. The present research will be conducted in the agricultural year 2017/18 in the city of Botucatu-SP. The experimental design will be in randomized blocks, in a 2x4 factorial scheme, with 4 replicates. The treatments will be composed of two forage species (Urochloa brizantha and Urochloa ruziziensis) and four forms of nitrogen fertilization management of maize crop, being: I) control (0 kg ha-1 of N), II) application of 40 kg ha-1 of N in sowing + top dressing 120 kg ha-1 of N in the V6 stage of the corn, III) 10 to 5 days before killing the grass, and IV) 5 to 1 day before sowing of the corn crop, at a dose of 120 kg ha-1 of N, using ammonium sulfate as the N source. N fertilization of 40 kg ha-1 at sowing will be used in all N treatments. The nutritional status, grain production and yield components of the corn crop will be evaluated; as well as dry matter production, persistence and release by grass species, and the contents of NH4 + and NO3 - and soil pH. The data will be submitted to analysis of variance by the F test (p d 0.05) and the results compared by the t test LSD (p d 0.05). (AU)