Greenhouse gas emission in an integrated crop-livestock system with grazing of lambs

• Grant number: 18/10872-9
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): July 01, 2018
• Effective date (End): August 11, 2020
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Juliano Carlos Calonego
• Grantee: Yasmin Marinetto Resende
• Home Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The inclusion of legume species in integrated crop-livestock system (ICLs) under no-tillage (NT), mainly in consortium or rotation with forage species , like Panicum and Urochloa, is important to increase the N contribution in the soil, via biological fixation of the atmospheric N, because ICLs are still limited by the N deficiency, with high dependence on the use of nitrogen fertilizer. In addition, the grazing intensity may affect the increase of organic matter in the soil and sustainability of the conservation systems. The objective of this work will be to evaluate the greenhouse gases emission (GHG) and the C stocks in the soil, as well as the production of soybean intercropped with aruana grass for whole plant silage, depending of the intense or moderate grazing of black oats by lambs, or without grazing, in autumn-winter in areas with differentiated corn consortium histories for silage production. The research will be conducted at the College of Agricultural Sciences, São Paulo State University, Botucatu, São Paulo State, Brazil, between 2018 and 2019. The experimental design will be a randomized complete block experimental design in a split-plot arrangement with for replications. The plots will be consisted of the two modalities of growing maize for silage: in a simultaneous consortium with marandu grass and in a simultaneous consortium with marandu grass and pigeon pea. The growing maize for silage was done in the 2014/2015, 2015/2016, 2016/2017 and 2017/2018 seasons. The subplots (3) will be consisted of 2 graze heights of black oats (0,15 and 0,30 m of the soil) by lambs between June to October of 2018, or for the treatment without graze. In the summer season 2018/2019 will be grown the soybean in consortium with grass-aruana in total area. We will evaluate the amount of pasture produced, the C and N levels in the soil, the input on dry matter soil, C and N by plant residues and fluxes of greenhouse gases (CO2, N2O and CH4 from the soil). The results will be submitted to analysis of variance (F test) and the means will be compared by means of the LSD t test (pd0.05).