Controlled release fertilizer as source of nitrogen on cauliflower production in a drip irrigation system

• Grant number: 11/10453-7
• Support Opportunities: Scholarships abroad - Research
• Start date: December 15, 2011
• End date: December 14, 2012
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Simone da Costa Mello
• Grantee: Simone da Costa Mello
• Host Investigator: Lincoln Zotarelli
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Institution abroad: University of Florida, Gainesville (UF), United States

Abstract

Nitrogen is an element which the cauliflower longer requires for the production of vegetative and reproductive organs, but in many situations, the application of N fertilizer usually has exceeded demand by plants and nitrate is not absorbed by the crop is leached. The reduction in the efficiency of N utilization should not be just the rate, frequency and type of fertilizer applied, but the inadequate irrigation management, characterized by applying mainly of large volumes of water at low frequency. Thus, management practices that increase the efficiency of water use and fertilizer application, also improve the efficiency of nitrogen fertilizer for crops, such as the use of controlled-release nitrogen fertilizers. In Brazil, however, this system is little practiced in vegetable production for lack of technical knowledge. In the U.S., controlled-release nitrogen fertilizers have been used together with conventional fertilizers in vegetable production to reduce the environmental impact caused by water contamination of groundwater by nitrate, especially without reducing production. The aim of this study will evaluate the use of controlled release urea associated with the use of conventional urea on yield of cauliflower and the environmental impact caused by the leaching of nitrogen. For cultivation of cauliflower, treatments will consist of: 1) application of 20% N as urea and controlled-release 80% of N by conventional urea, 2) application of 40% of N as controlled-release urea and 60% of N by conventional urea, 3) application of 60% N as urea and controlled-release 40% of N by conventional urea, 4) application of 100% N in the form of controlled release urea, 5) application of 100% N as urea conventional, 6) control (0% N). The controlled release urea is applied at planting and conventional urea is applied at planting and at 20 and 40 days after transplanting on the proportions of 30%, 35% and 35% respectively. The total dose of N is 225 kg / ha. The experimental design is the randomized blocks with six treatments and four replications. Each plot will consist of 40 plants grown at 0.8 m spacing between rows and 0.4 m between plants, totaling 24 plots.Will be assessed the following characteristics: soil nitrate leaching and ammonia volatilization, chemical characteristics of soil solution by the use of fertilizers, growth curve and extraction of nitrogen by the plant cauliflower, yield and crop quality. (AU)