Nitrogen dynamics in a cropping system with forages as cover crops and corn

• Grant number: 16/25253-7
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: February 01, 2017
• End date: April 30, 2019
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Agreement: BBSRC, UKRI ; CONFAP ; Newton Fund, with FAPESP as a partner institution in Brazil
• Principal Investigator: Ciro Antonio Rosolem
• Grantee: Camila da Silva Grassmann
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated research grant: 15/50305-8 - A virtual joint centre to deliver enhanced nitrogen use efficiency via an integrated soil-plant systems approach for the UK & Brazil, AP.TEM
• Associated scholarship(s): 18/09622-8 - Elucidating the effects of forage grass exudates upon soil N cycling and microbiota, BE.EP.DD

Abstract

Forages of the genus Urochloa can affect N dynamics in the soil, reducing its availability to maize grown in succession. The objective of this study is to assess the effect of Urochloa ruziziensis, Urochloa brizantha and Panicum maximum on soil N dynamics, evaluating: (i) the nitrification potential, (ii) ammonia, (Iii) the possible N output routes of the system as N2O and NH3 volatilization or NO3- leaching, and (iv) the effect on the development of maize grown in succession. For this, an experiment was installed on a clay dystroferric red nitosol. The experimental design is a complete radomized block design (3x4) with three species of forage grasses (U. ruziziensis, U. brizantha and P. maximum) and four N doses (0, 70, 140 and 210 kg Ha-1) applied to maize, with four replications. At the beginning of the experimental years (2016-2019), the maize crop is being sowed under no-till after desiccation of the forage. N inputs in the system are evaluated through deposition by rainwater and dust, as well as nutrient output via N2O and NH3 volatilization and NO3- leaching. The levels of NH4 + and NO3-, C-total, N-total and N-organic in the soil profile, the nitrification potential and the activity of the ammonifying and nitrifying microorganisms are also being studied. The soil solution is being collected at 80 cm depth to verify N losses. Soil profile moisture is being monitored by means of a capacitive probe (Diviner 2000®) for future correlation with N concentrations in the leachate. Biomass production is being evaluated in forages and maize, as well as corn grain yield, in addition to quantification of N content in the plant tissue. The results obtained will be submitted to the analysis of the variance and presenting significance will be submitted to the T test at 5% for the grasses factor and regression for the doses of N. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ROCHA, KASSIANO F.; MARIANO, EDUARDO; GRASSMANN, CAMILA S.; TRIVELIN, PAULO C. O.; ROSOLEM, CIRO A.. Fate of N-15 fertilizer applied to maize in rotation with tropical forage grasses. FIELD CROPS RESEARCH, v. 238, p. 35-44, MAY 15 2019. (15/50305-8, 16/25253-7, 17/02517-1)

GRASSMANN, CAMILA S.; MARIANO, EDUARDO; DINIZ, PRISCILA P.; BORGES, BEATRIZ M. F.; BORGES, CLOVIS D.; TSAI, SIU M.; ROSOLEM, CIRO A.. Functional N-cycle genes in soil and N2O emissions in tropical grass-maize intercropping systems. SOIL BIOLOGY & BIOCHEMISTRY, v. 169, p. 12-pg., 2022-06-01. (15/50305-8, 16/25253-7, 17/02517-1)

GRASSMANN, CAMILA S.; MARIANO, EDUARDO; ROCHA, KASSIANO F.; GILLI, BRUNO R.; ROSOLEM, CIRO A.. Effect of tropical grass and nitrogen fertilization on nitrous oxide, methane, and ammonia emissions of maize-based rotation systems. Atmospheric Environment, v. 234, AUG 1 2020. (15/50305-8, 16/25253-7, 17/02517-1)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

GRASSMANN, Camila da Silva. Maize-based systems as affected by forage grass and nitrogen fertilization: elucidating 15N recovery, greenhouse gas emissions, N-cycle functional genes in soil and crop yields. 2021. Doctoral Thesis - Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agronômicas. Botucatu Botucatu.