Modeling the dynamics of soil organic matter in long-term cover-cropping systems

• Grant number: 22/00230-5
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: July 15, 2023
• End date: February 20, 2024
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Carlos Alexandre Costa Crusciol
• Grantee: José Roberto Portugal
• Supervisor: Marcelo Valadares Galdos
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Institution abroad: Rothamsted Research, England
• Associated to the scholarship: 20/05997-7 - Long-term cover-cropping systems: 15N-fertilizer recovery and soil organic matter quality affected by intercropping, BP.PD

Abstract

This research is a continuation of a long-term cover-cropping experiment initiated in the 2006 season at Lageado Experimental Farm in Botucatu - SP. This is experiment part of the Global Long-Term Agricultural Experiment Network organized by Rothamsted Research. In tropical regions, crop rotation and cover crop adoption are necessary to increase soil organic matter (SOM) in conservation agricultural systems such as no-tillage systems. However, climate change scenarios require a better understanding of which production systems have the greatest potential to mitigate emissions and promote agricultural adaptation. We hypothesize that long-term cropping systems that adopt intercropped cover crops will increase carbon sequestration and agricultural resilience under climate change. The objective is to evaluate SOM dynamics in intercropped systems using two process-based models: DayCent and Microbial Efficiency-Matrix Stabilization (MEMS). The treatments consist of four cropping systems (I - soybean-maize-fallow; II - soybean-maize-forage; III - soybean-maize-green manure; IV - soybean-maize-forage+green manure). The models will be parameterized and calibrated using data on soil, climate and management practices obtained from experiments. Data on particulate organic matter (POM) and organic matter associated with minerals (MOAM) at depths of 0-5, 5-10, 10-20, 20-40, 40-60, 60-80 and 80-100 cm e gas emissions (N2O, NO e CO2) at depths of 0-20 cm will be used to evaluate the models. The partnership between UNESP and Rothamsted on this proposal will further elucidate the effect of sustainable management practices on tropical agricultural systems. (AU)