Advanced search
Start date

The effect of variable rate fertilization on yield of orange trees over four seasons of evaluation

Grant number: 11/05303-6
Support Opportunities:Scholarships in Brazil - Master
Effective date (Start): March 01, 2012
Effective date (End): January 31, 2013
Field of knowledge:Agronomical Sciences - Agricultural Engineering - Agricultural Machinery and Implements
Principal Investigator:José Paulo Molin
Grantee:André Freitas Colaço
Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil


The orange crop is of great importance for the Brazilian and global agribusiness. Due to its high technology and constant search for profits improvements, new technologies that can optimize the productive processes have been investigated by the sector. Among them we find the precision agriculture (PA), that propose a management system capable of dealing with spatial variability of fields and then optimize the use of inputs. One of the main tools used on PA is the application of inputs, especially fertilizers and lime, on a variable-rate, i.e. according to the local demand and the spatial variability found in the field. This technique has been studied for citrus crop. However, none study had approached this issue on a continuous way and with a sufficiently long time of evaluation, that could assess the influence of this fertilization practice on the orchards yield on the long-term. So, the objective of this study is to evaluate the variable-rate fertilization on orange crop using orchards that has already been carried out with this practice and to analyze the effects on yield, plants nutrition and fruit quality after four seasons of variable-rate utilization. For that, it will be used two fields with the following treatments - that have been carried out since 2008: variable-rate fertilization (VR) and fixed-rate fertilization (FR). It will be collected soil and leaf samples on a geo-referenced grid and also the yield maps. From this data it will be calculated the fertilizer recommendation and proceed the variable-rate fertilization on the VR treatment, so it can be compared to the conventional fertilization used on the FR treatment. Results obtained on four seasons will be analyzed from soil fertility maps, plants nutrition and yield maps generated for both treatments, allowing analysis and interpretation of spatial and temporal variability, and comparison between variable-rate and fixed-rate fertilization.

News published in Agência FAPESP Newsletter about the scholarship:
Articles published in other media outlets (0 total):
More itemsLess items

Scientific publications
(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)
COLACO, A. F.; TREVISAN, R. G.; KARP, F. H. S.; MOLIN, J. P.. Yield mapping methods for manually harvested crops. COMPUTERS AND ELECTRONICS IN AGRICULTURE, v. 177, p. 14-pg., . (11/05303-6)
COLACO, A. F.; MOLIN, J. P.. Variable rate fertilization in citrus: a long term study. PRECISION AGRICULTURE, v. 18, n. 2, p. 169-191, . (11/05303-6)
Academic Publications
(References retrieved automatically from State of São Paulo Research Institutions)
COLAÇO, André Freitas. Effects of variable rate fertilization on orange groves during four seasons. 2013. Master's Dissertation - Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) Piracicaba.

Please report errors in scientific publications list using this form.