Monitoring of nutritional status and soil solution in citrus plants fertigated

• Grant number: 10/17006-3
• Support type: Regular Research Grants
• Duration: January 01, 2011 - December 31, 2012
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal researcher: Roberto Lyra Villas Boas
• Grantee: Roberto Lyra Villas Boas
• Home Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Assoc. researchers: Diógenes Martins Bardiviesso ; Thais Regina de Souza ; Thomas Fiore de Andrade

Abstract

The state of São Paulo is responsible for about 85% of national citrus production and the use of irrigation in orchards has been increasing significantly in recent years because of promising results such as raising productivity, improving fruit quality and the possibility of production out of time. Fertilizer application is an extremely important factor in any agricultural production, including the citrus industry. A sloppy application can cause damages to the producer due to the percentage that this input represents on the cost of production and in some extreme situations, can promote a decrease in productivity. The fragmentation of the fertilizer through located fertigation, according to the different stages of development, could become one of the best ways to promote appropriate use of nutrients by the plant, increasing the efficiency of fertilization. However, for this fragmentation of the fertilizer to be effective, it is necessary to develop curves of absorption of nutrients, which is very difficult in a culture like the citrus. Being so, the project aims to study techniques such as analysis of the sap, indirect determination of chlorophyll index and analysis of soil solution, to monitor the nutritional status of citrus plants and provide a better split fertigation, according to the nutritional need of the plant, thereby increasing the efficiency of nutrient use. The project is in its third year of implementation, on the Emu farm, belonging to the company "Citrovita" located in the city of Reginópolis-SP. There is a drip irrigation system installed in orange scion variety Hamlin and Valência, both on rootstock citrumelo 'Swingle' and the treatments are defined by five different doses of N, P2O5 and K2O in the forms of ammonium nitrate (33% N), phosphoric acid business (70% P2O5) and potassium chloride white (60% K2O). This project aims to continue the project FAPESP 07/55899-7 that rated this monitor for 2 years. (AU)