Parameterization of contribution of biopores in no-tillage for root growth modelling of soybean and maize

• Grant number: 23/11945-8
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2024
• End date: January 31, 2025
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Moacir Tuzzin de Moraes
• Grantee: John Kennedy dos Santos
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

No-tillage system plays a key role in improving soil structure and consequently in the chemical, physical and biological quality of agricultural soils. The hypothesis is that a model based on the root elongation as a function of mechanical and hydric stress incorporate the effects of biopores and continuous pores to mitigate the physical stress for root growth. The objective of this proposal is to test whether the use of a model based on root elongation rate as a function of mechanical resistance and matric potential can incorporate the effects of biopores and continuous pores from no-tillage to improve the root growth models of tap-rooted (soybean) and fasciculate (maize) root systems. Experiments in soil samples with preserved and unstructured structure will be carried out to determine the impact of hydric (i.e., obtained by different matric potentials of -1, -6, -10, -100 and -500 kPa) and mechanical (i.e., obtained through levels of management and degrees of soil compaction) stress to the root elongation rate of tap-rooted and fasciculate root systems. Root elongation rates of soybean and maize seedlings will be quantified in soil samples (15 cm in height and ~5 cm in diameter) after incubation in a growth chamber. Soil penetration resistance, soil moisture, saturated hydraulic conductivity, pore distribution and soil water retention curve will be determined. Models of the relationship between crop root growth and mechanical and hydric stress will be quantified and applied in the simulation of crop root growth through process-based models. The expected results of this project will be useful for the conception of how much and how the soil structure in no-tillage system contribute to mitigate the mechanical and hydric stresses for crops with tap-rooted and fasciculate root systems.