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Rotation systems and phosphate fertilization onsugarcane in the savannahs

by Manzi Gama, Ailton Júnio

Abstract (Summary)
Considering the possible negative effects caused by sugarcane through the years, culture rotationcan yield several benefits, including the improvement of phosphorus use. Low phosphorusavailability in the savannahs is a major restriction factor form sugarcane yield in thisenvironment. This study analyzed the effect of culture rotation and phosphate fertilization consugarcane yield and its technological quality. The test was done in two different soil types, clayand sandy soils. The culture rotation system consisted of soybean or Crotalaria juncea, cultivatedfor one or two subsequent years. The phosphorus source was magnesium thermo-phosphate, at170 kg ha-1 P2O5. The experimental design was randomized blocks with split plot as a 5x2factorial, with: 5 rotation systems in the plots (fallow, soybean for one year, two consecutiveyears of soybeans, one year with crotalaria or two consecutive years of crotalaria), with orwithout phosphate fertilization in the split plot and four repetitions. Sugarcane was planted inMarch 2004, after the rotation management. The sugarcane parameters analyzed were: tillering,stalk biometry, technological analyses (sugarcane POL, syrup BRIX and syrup P2O5), stalk andsugar yield. Chemical analysis of the two soils was done after sugarcane harvest. Sugarcane leafanalysis was done, after 8 months of ratoon growth. The rotation systems affected positively, onboth experiments, biometry, stalk yield and P soil level. While phosphate fertilization increasedsoil phosphorus, magnesium and base saturation levels in both experiments, also increasing P2O5concentration in the syrup of the first year sugarcane, stalk and sugar yield increases were foundonly on the sandy soil, for both phosphate fertilization and rotation systems. The best rotationsystem in this soil was found on two consecutive years of soybeans. However, in the clay soil, thegreatest stalk yield was found in areas cultivated for two years with crotalaria. Althoughphosphate fertilization increased soil P levels in both soils, no differences were observed in leaf Pconcentration of ratoon sugarcane after 8 months of growth.
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Carlos Ribeiro Rodrigues; Suzana Pereira de Melo; Fabio Luis Ferreira Dias; Gaspar Henrique Korndorfer

School:Universidade Federal de Uberlândia

School Location:Brazil

Source Type:Master's Thesis

Keywords:Crotalária Phosphorus Crotalaria Soybean Yield

ISBN:

Date of Publication:03/19/2007

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