Temporal Variation in Leaf Nutrient Concentrations of Irrigated Jatropha curcas under Nitrogen Fertilization
Clayton Moura de Carvalho *
Federal University of Ceará (UFC), Center for Agricultural Sciences, Department of Agricultural Engineering, Postgraduate Program in Agricultural Engineering, Av. Mister Hull S/N, Campus do Pici, CEP: 60.455-970, Fortaleza, Ceará, Brazil.
Thales Vinícius de Araújo Viana
Federal University of Ceará (UFC), Center for Agricultural Sciences, Department of Agricultural Engineering, Postgraduate Program in Agricultural Engineering, Av. Mister Hull S/N, Campus do Pici, CEP: 60.455-970, Fortaleza, Ceará, Brazil.
Albanise Barbosa Marinho
Federal University of Paraíba (UFPB), Center for Technology - Campus I, Conjunto Presidente Castelo Branco III, Castelo Branco, CEP: 58.033-455, João Pessoa, Paraíba, Brazil.
Manoel Valnir Júnior
Federal Institute of Ceará (IFCE), Sobral Campus, Natural Resources Axis, Avenida Doutor Guarani - 317, Derby Clube, CEP: 62.042-030, Sobral, Ceará, Brazil.
Raimundo Rodrigues Gomes Filho
Federal University of Sergipe (UFS), Center for Agricultural Sciences, Av. Marechal Rondon s/n, Jardim Rosa Elze, CEP: 49.100-000, São Cristóvão, Sergipe, Brazil.
Leonaria Luna Silva de Carvalho
Federal University of Ceará (UFC), Center for Agricultural Sciences, Department of Agricultural Engineering, Postgraduate Program in Agricultural Engineering, Av. Mister Hull S/N, Campus do Pici, CEP: 60.455-970, Fortaleza, Ceará, Brazil.
Gabriel Teles Santos da Silva
Federal Rural University of the Semi-Arid Region (UFERSA), Center for Agricultural Sciences, Presidente Costa e Silva, CEP: 59.625-900, Mossoró, Rio Grande do Norte, Brazil.
*Author to whom correspondence should be addressed.
Abstract
Cultivation of Jatropha curcas L. has been promoted because of its potential as a non-edible oilseed crop for clean-energy applications and its adaptation to arid and semi-arid environments. This study evaluated temporal variation in foliar macro- and micronutrient concentrations in irrigated J. curcas under different nitrogen fertilisation doses. The field experiment was conducted in a semi-arid region of north-eastern Brazil using a randomised block design with split plots. Four nitrogen doses were evaluated, and post-treatment foliar sampling was conducted at 145 and 271 days after standardisation pruning; the 75-day sampling was used only as a pre-treatment baseline covariate. Healthy, mature leaf blades free from pest and disease damage were collected for nutrient analysis. Nitrogen, phosphorus, potassium, calcium, magnesium, iron, zinc, and manganese were determined. Nitrogen fertilisation did not significantly influence the foliar concentrations of the evaluated macro- or micronutrients under the studied conditions. Sampling period significantly affected the macronutrients and the foliar concentrations of iron and zinc, whereas manganese did not vary significantly with sampling period. Across the sampling periods, macronutrient concentrations followed the order N > Ca > K > Mg > P, while micronutrient concentrations followed Fe > Mn > Zn. These findings indicate that temporal variation in leaf nutrient status was more evident than the response to the tested nitrogen doses during the evaluated period.
Keywords: Jatropha curcas L, drip irrigation, plant nutrition