Least Limiting Water Range in area cultivated with grain yield under no - tillage system for 25 years in Campinas, SP.

• Grant number: 10/04880-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2010
• End date: February 29, 2012
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Sonia Carmela Falci Dechen
• Grantee: Fernando Rodrigues Moreira
• Host Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil

Abstract

Agricultural practices have changed the soil structure, and therefore, their physical and hydraulic properties. The no-tillage system promotes the improvement of physical and chemical properties and the increased of nutrients and water stored in soils. Thus, the amount of water retained in the soil varies and the concept of water available to plants becomes difficult to interpret. The Least Limiting Water Range (LLWR) is a method that evaluates the structural quality of the soil and it is the range of moisture in which there is no restriction of aeration and mechanical resistance to root penetration. Further researches regarding the Least Limiting Water Range are fundamental to understanding the physical and hydraulic properties of soil. Disturbed and undisturbed samples will be collected, at depths of 0,0-0,1 m, 0,1-0,2 m and 0,2-0,3 m, to obtain the following parameters: bulk density; penetration resistance curve; and the soil water retention curve. These samples will be used to calculate the Least Limiting Water Range. This study will be carried out to determine the physical and the Least Limiting Water Range of soil under consolidated no-tillage system since 1985 with grain crops in rotation, in Campinas, São Paulo State, Brazil.