NITROGEN FERTILIZATION AND MAIZE INTERCROPPED WITH Urochloa ruziziensis AS SOIL PHYSICAL AND CARBON AMELIORATION IN A LONG-TERM INTENSIFIED SYSTEM

• Grant number: 25/20719-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2025
• End date: November 30, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Juliano Carlos Calonego
• Grantee: Vitor Gerbi Baptista
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Soil quality is defined as the capacity of the soil to fully perform its ecological and productive functions, such as sustaining plants and microorganisms, regulating water and air flows, recycling nutrients, storing carbon, and maintaining a healthy environment. Soil physical quality is a key indicator of agricultural sustainability because it is related to the soil's ability to provide a suitable environment for root growth, water infiltration, and the storage of water and oxygen. However, the physical attributes of the soil are sensitive to management practices and reflect the changes imposed by agricultural practices. In this context, the objective of this project is to evaluate the soil physical quality and carbon accumulation in an intensified soyben-maize production systems intercropped with Urochloa ruziziensis under nitrogen fertilization. The study will be carried out in a long-term experiment (7 years) with soybean-maize grown either in monoculture or intercropped with U. ruziziensis, under two nitrogen fertilization rates (0, 60 e 180 kg ha¿¹ of N), in a randomized block design with four replications. The soil physical attributes (bulk density, total porosity, macro- and microporosity, aggregate stability, clay dispersion in water, and degree of flocculation) and soil carbon (carbon stocks) will be evaluated at the following depths: 0-10, 10-20, 20-40, 40-60, 60-80, and 80-100 cm. Soil penetration resistance and the input of N and N through roots will be evaluated down to a depth of 60 cm. In addition, biomass input, C and N by the crops, and crop yield will be assessed. The data obtained will be subjected to analysis of variance (ANOVA), and when significant, means will be compared using the t test at a 5% significance level. (AU)