Journal of Agricultural Science; Vol. 11, No. 7; 2019 ISSN 1916-9752 E-ISSN 1916-9760 Published by Canadian Center of Science and Education 86 Nitrogen Management in Maize Under Rainfed Conditions in the Brazilian Semiarid Region Micaela B. Pereira 1 , José L. dos S. Gomes 1 , Vademir R. Cavalcante 2 , Bruno de S. Oliveira 1 , Jackson T. Lobo 1 , João E. da S. Ribeiro 1 & Fabio Mielezrski 1 1 Federal University of Paraíba, Areia, Paraíba, Brazil 2 State Agricultural Research Company of Paraíba (EMEPA), Alagoinha, Paraíba, Brazil Correspondence: Micaela B. Pereira, Federal University of Paraíba, 12, Rod Pb-079, Areia, Paraíba, Brazil. Tel: 55-839-8123-2683. E-mail: micaelle.bp@gmail.com Received: February 25, 2019 Accepted: March 28, 2019 Online Published: May 31, 2019 doi:10.5539/jas.v11n7p86 URL: https://doi.org/10.5539/jas.v11n7p86 Abstract Zea mays L. presents socioeconomic and cultural importance for the Northeast region of Brazil, its yield is directly related to the productive system, to the edaphoclimatic conditions and to the soil management. The aim of this work was to evaluate the development and the yield of maize under different nitrogen doses in rainfed conditions in the Brazilian semiarid. The experimental design was in randomized blocks, with four treatments and five replications, totalizing 20 experimental plots, with 24 plants each. The treatments were: T1 (0 kg ha -1 of N); T2 (40 kg ha -1 of N); T3 (60 kg ha -1 of N) and T4 (80 kg ha -1 of N). Were evaluated: plant height, culm diameter and number of leaves at 30, 45, 60, 75 and 90 days after emergence; leaf temperature, stomatal conductance, transpiration, liquid photosynthesis and intercellular carbon concentration at 65 days after emergence; yield, shoot dry mass and nitrogen content in the soil after harvest. The different nitrogen doses significantly influenced the plant height, culm diameter and the number of leaves in the different evaluation periods, also influencing the nitrogen levels in the soil after the harvest. There was no difference among treatments for the yield, the registered average was 5,205 kg ha -1 . The development of the crop and the nitrogen absorption may have been influenced by the water deficit during the crop cycle. The maize presented better agronomic performance with the dose of 60 kg ha -1 of nitrogen. Keywords: nitrogen fertilization, growth, water deficit, productivity, gas exchange, Zea mays 1. Introduction Agricultural production systems, in terms of area and socio-economic importance, are prominent throughout the world. The maize (Zea mays L.) presents a great importance among the cultivated species, being part of the human and animal food chain, due to its grain yield and forage production, being one of the most produced inputs in Brazil and in the world (Souza et al., 2012; Custódio et al., 2016; USDA, 2018). In the fifth survey of the 2018/2019 harvest conducted by the United States Department of Agriculture, the global production of maize was estimated in 1.07 billion tons (USDA, 2018). In the world ranking, Brazil is the third largest producer with 82 million tons estimated for the 2018/2019 harvest. In the 2016/2017 harvest, maize cultivation in Brazil was performed in an area of 16.1 million hectares, with the Northeast region being responsible for 11.72% of this total area, and the state of Paraíba with participation of 8.4 million hectares (CONAB, 2017). Maize crop productivity is directly related to the entire production system, involving the genetic potential of the variety, the edaphoclimatic conditions and the management employed. Among the cultural practices, the management of soil fertility is of great importance in order to achieve higher productivity (Santos et al., 2014; Lins et al., 2017). Among the macronutrients required by the maize crop, nitrogen (N) is absorbed in higher quantity. Besides its effect on productivity, this nutrient has importance in the biochemical processes of the plant, as a constituent of proteins, enzymes, coenzymes, nucleic acids and chlorophyll (Lourente et al., 2007; Santos et al., 2010). However, nitrogen fertilizers are among the inputs that most burden production, needing to be applied in