Sugarcane root development and physical, chemical and biological soil attributes as affected by soil tillage systems.

Abstract

Soil tillage systems are closely linked to changes in soil physical, chemical and biological attributes related to drainage, infiltration, mineralization and erosion. Knowledge of the changes in soil attributes and their impact on plant growth has fundamental importance. Thus, soil tillage can modify the soil bulk density, structure and aggregation and, if inadequate, to compromise nutrient uptake and root growth. The expansion of sugarcane crop to areas previously under pastures has brought concerns because these areas have been established mostly on fragile soils as Ultisols and Alfisols in the West of the State of São Paulo. The objective of this project is to evaluate the effect of adoption of three tillage systems on soil physical, chemical and biological attributes, as well as on yield and root growth of sugarcane crop. The study will be developed in Pindorama, Piracicaba and Campinas municipalities, State of São Paulo. In Pindorama the treatments will be applied in three systems consisting of conventional tillage, no tillage and minimum tillage. In Piracicaba the treatments will be applied in systems of conventional tillage and deep subsoiling (0.80 m) + rotary tiller (0.40 m). In Campinas the treatment will consist of straw levels on the surface for evaluation of the soil and water erosion losses. In the plant will be evaluated root growth and sugarcane crop yield. The following soil attributes will be evaluated: texture, water retention curve, bulk density, porosity, aggregation, penetration resistance, hydraulic conductivity, air permeability, least limit water range (LLWR), fertility, carbon and nitrogen storage, CO2 quotient as well as water erosion. The project will be developed during 24 months.