Manejo da irrigação com água salina na cultura do milho no Maciço de Baturité-Ce

• Autor(a) principal: Rodrigues, Valdécio dos Santos
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/40360
• topic: Zea mays L.; Estresse salino; Trocas gasosas; Produtividade; Química do solo

Corn is one of the most produced crops worldwide and stands out as a source of income and food for many producers in various regions of the planet. Due to the increasing demand for good quality water for human consumption, especially in arid and semi-arid regions, there is pressure for agricultural producers to use water of inferior quality. The objective of this study was to evaluate the influence of irrigation with saline water on the gas exchange and yield of the maize crop, as well as the chemical attributes of the soil. The study was conducted in the field from August to December 2017 at the Experimental Farm of the University of International Integration of Afro-Brazilian Lusophony (UNILAB), Redenção-CE. A randomized complete block design with five irrigation water salinity levels (1.0, 2.0, 3.0, 4.0 and 5.0 dS m-1) and four replications was used. The physiological variables (photosynthesis, transpiration, stomatal conductance, CO2 internal concentration, leaf temperature and water use efficiency) were evaluated at 45 days after sowing (DAS) and the production variables (spike mass with straw and straw without straw, length and diameter of the spur without straw, mass of the cob, mass of 1000 grains and productivity) and soil chemical attributes (soil electrical conductivity, soil solution pH, calcium, magnesium, potassium , sodium and percentage of exchangeable sodium). The salinity of irrigation water reduced photosynthesis, stomatal conductance, transpiration and internal CO2 concentration and increased leaf temperature and water efficiency. Regarding the production variables, it was verified that the increase of the concentration of the salts of the irrigation water reduced the mass of the spike with straw and without straw, mass of the cob, mass of 1000 grains and productivity. The length and the diameter of the spike were not influenced by the increase of the salinity of the water. On the chemical attributes of the soil analyzed, it was verified that irrigation with increasing salinity water reduced the calcium and potassium contents of the soil solution, but increased the salinity, the sodium content and the percentage of exchangeable sodium in the soil. Magnesium content and pH of the soil solution were not influenced by the increase in water salinity.