Influence of irrigation and nitrogen fertilization in yield and quality of oil from jatropha seeds

Author(s)

Irineu Pedro de Sousa Andrade

• Document type: Doctoral Thesis
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2016-07-22

Examining board members

Marcos Vinicius Folegatti; Sergio Nascimento Duarte; Danilton Luiz Flumignan; Jefferson Vieira José; Leonardo Duarte Batista da Silva

• Advisor: Marcos Vinicius Folegatti

Abstract

With the search for new solutions for the sustainable energy production, new renewable energy sources have been the subject of studies for the power supply in the world, reducing dependence on fossil fuels. Biodiesel can be used for power generation as a substitute for oil diesel, which have increased the interest on oilseeds crops studies. The jatropha (Jatropha curcas L.) is a species of the Euforbiaceae family that has stood out for being a perennial, rustic, and high yield of oil plant. The knowledge of the effects of irrigation and nitrogen fertilization on the cultivation become relevant for a better crop management. The main objective of this study was the evaluation of the effects of different levels of nitrogen fertilization and irrigation on productivity, vegetative growth and oil quality in the jatropha crop. The experiment was conducted in an experimental area of the Department of Biosystems Engineering at ESALQ/USP, in Piracicaba-SP. The studies were conducted in the agricultural years of 2013/2014 and 2014/2015, with plants from the third year of cultivation, arranged in 3x4 meters spacing, totaling 833 plants ha-1. The treatments were randomly arranged in two cultivation areas with blocks composed of four repetitions being the factors consisted of two water management (irrigated and without irrigation) and four doses of nitrogen fertilization from its fertilizer recommendation (150%, 100%, 50% and 0% N). Each cultivation area was composed by the type of water management adopted and the data analysis was made jointly as experiments group analysis. The irrigation system used was the center pivot, being adopted for the entire irrigated area the same irrigation management. The irrigation and nitrogen levels had a positive influence on growth variables such as height, diameter and canopy volume. All evaluated chlorophyll levels reached the highest values with the practice of irrigation and higher nitrogen levels applied, but despite of this difference, all treated samples showed low correlation with leaf nitrogen content. The productivity of seeds and jatropha oil also responded positively to the treatments applied, reaching three times their values with the practice of irrigation and nitrogen fertilization. The oil content did not vary with treatments as to its intrinsic content per unit mass of seeds, and only the water management factor influenced the values of some oil quality indices such as acidity, iodine, peroxide and oxidative stability, when the irrigated treatments showed better results in general. Thus, it is concluded that even though being adapted to adverse conditions of climate and soil, jatropha responds well to practices of irrigation and nitrogen fertilization, increasing its productivity and improving its vegetative growth and quality of oil for biodiesel production. (AU)

• FAPESP's process: 13/14778-3 - Irrigation and nitrogen fertilization in cultivation and oil quality jatropha
• Grantee: Irineu Pedro de Sousa Andrade
• Support Opportunities: Scholarships in Brazil - Doctorate