Doses de fósforo alteram a homeostase iônica do feijão-caupi irrigado com água salina

Soil and water salinization problems are increasingly common in arid and semi-arid regions, so it is necessary to adopt technologies that enable the use of these natural resources in agriculture, allowing satisfactory plant development. Thus, the objective of this study was to evaluate the effects of saline water irrigation associated with phosphate fertilization on soil salinity and on phytomass accumulation and nutrient concentration in cowpea plants. The study was carried out in a greenhouse using a randomized block design in a 5 x 3 factorial scheme consisting of five electrical conductivity of irrigation water electrical conductivities (0.5, 1.5, 2.5, 3.5 and 4.5 dS m-1) and three phosphorus doses (60, 100 and 140% of the recommended dose 60 kg P2O5 ha -1), with five repetitions. Plants were cultivated in 8 dm3 lysimeters until the flowering stage and, during this period, soil salinity, phytomass accumulation and nutrient concentration in the plant tissue were evaluated. Irrigation with water with electrical conductivity above 2.5 dS m-1 increased soil salinity and sodium concentration in the tissues to toxic levels, reducing phytomass accumulation and concentrations of macronutrients in cowpea plant tissue, except for nitrogen. Application of 60% of the recommended dose of phosphorus for cowpea improves its ionic homeostasis, increasing the absorption of potassium and calcium, but does not reduce the deleterious effects of high salinity on phytomass accumulation.

[1]  J. R. T. D. Albuquerque,et al.  Tolerance of peanut (Arachis hypogea) genotypes to salt stress in the initial phase , 2020, Revista Brasileira de Engenharia Agrícola e Ambiental.

[2]  J. Dombroski,et al.  Water use of cowpea under deficit irrigation and cultivation systems in semi-arid region , 2019, Revista Brasileira de Engenharia Agrícola e Ambiental.

[3]  E. Paiva,et al.  Growth, gas exchange and photochemical efficiency of the cowpea bean under salt stress and phosphorus fertilization , 2019, Comunicata Scientiae.

[4]  Rui-dong Huang.  Research progress on plant tolerance to soil salinity and alkalinity in sorghum , 2018 .

[5]  Pamwenafye I. Nanhapo,et al.  Mixed cropping with ice plant alleviates the damage and the growth of cowpea under consecutive NaCl treatment and after the recovery from high salinity , 2017 .

[6]  Bingru Huang,et al.  Mechanism of Salinity Tolerance in Plants: Physiological, Biochemical, and Molecular Characterization , 2014, International journal of genomics.

[7]  J. P. Syvertsena,et al.  Multiple abiotic stresses occurring with salinity stress in citrus , 2014 .

[8]  S. Álvarez,et al.  Water relations, nutrient content and developmental responses of Euonymus plants irrigated with water of different degrees of salinity and quality , 2013, Journal of Plant Research.

[9]  B. C. Tripathy,et al.  Salt and genotype impact on antioxidative enzymes and lipid peroxidation in two rice cultivars during de-etiolation , 2013, Protoplasma.

[10]  F. Damatta,et al.  Salt tolerance is associated with differences in ion accumulation, biomass allocation and photosynthesis in cowpea cultivars , 2009 .

[11]  M. Ashraf,et al.  Biotechnological approach of improving plant salt tolerance using antioxidants as markers. , 2009, Biotechnology advances.

[12]  R. Munns,et al.  Approaches to increasing the salt tolerance of wheat and other cereals. , 2006, Journal of experimental botany.

[13]  Henrique M. Morais,et al.  Interação entre salinidade e fósforo em plantas de sorgo forrageiro , 2006 .

[14]  J. F. Medeiros,et al.  Caracterização das águas subterrâneas usadas para irrigação na área produtora de melão da Chapada do Apodi , 2003 .