Relationshipd between spatial variability of soil attributes and of sugar cane yield

• Grant number: 08/04690-3
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2009
• End date: January 31, 2012
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Marcio Koiti Chiba
• Grantee: Marcio Koiti Chiba
• Host Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil

Abstract

This project has the objective of analyzing the relationships between the spatial variability of soil attributes and sugar cane crop yield. The experiment will be conducted in two distinct locations in terms of soil and management system. One of them will be at Fazenda Aparecida, Mogi Mirim, SP, in which the field selected is cultivated under no tillage for the last 12 years, with the sugar cane manually harvested after burningand the soil type is a Nitossolo. This field was selected because it has showed large variability in sugar cane yield in dry years. The other field is located at an experimental area of the Sugar Cane Center of Instituto Agronomico, located in Ribeirão Preto, SP, in which the sugar cane is harvested mechanically without burning, and the soil type is a Latossolo. This field has been showing high yield variability for the high performance sugar cane varieties which do not tolerate soil compaction. Soil attributes and sugar cane yield will be measured in 300 sampling points disposed in a 30 x 30 meters grid at the Nitossolo and on 202 points on a 10x10m grid on the Latossolo. In each sampling point, soil samples will be collected for soil compaction assessment, soil water infiltration rate, soil chemical and particle size distribution analysis and sugar cane yield. Geostatistics will be used in trems of semivariogram analysis and map construction with kriging interpolation technique. Topographic survey will be executed in both fields in order to build the digital elevation model and seek for interpretations of the maps for soil attributes and sugar cane crop yield as a function of the topographic height and relief position. The possibility of using ordinary and collocated cokriging interpolation techniques will be investigated, according to the spatial relationship between attributes. Indicator kriging will be used using threshold values for soil attributes regarding the sugar cane yield, thus the maps for the probability of reaching the established scenario will be built. Correlation between sugar cane yield and soil attributes will be evaluated with correlation coefficients and with map correspondence analysis. (AU)