Atributos químicos, fisiologia, nutrição e produção do maracujazeiro sob salinidade da água, revestimento lateral das covas e cálcio no solo

Abstract

The excess of soluble salts in soil and water, and low and irregular rainfall are the main problems in agriculture and justifies the need to consider measures to production in semiarid areas. In this sense, the work was carried out to evaluate the effects of irrigation with saline water, side lining of pits and application of calcium in Entisol fertility attributes cultivated with yellow passion fruit cv. BRS Giant Yellow. The treatments were arranged in a split plot in esuqema 2 x (2 x 5) corresponding to salinity (0.3 and 4.0 dS m-1), main plot, combined with pits without and with lateral protection of pits and calcium doses (0, 30, 60, 90 and 120 kg ha-1), subplots. The treatments were distributed in four randomized blocks and the experimental unit was formed by four plants. The variables evaluated were: electrical conductivity of soil saturation extract, pH, exchangeable bases, potential acidity, cation exchange capacity, base saturation and exchangeable sodium percentage. Data were subjected to analysis of variance and the effects of electrical conductivity of irrigation water (salinity) and protection of the pits were compared by the F test (p ≤ 0.05) and those related to calcium doses adjusted by regression by the F test (p ≤ 0.10). The increase in the electrical conductivity of the irrigation water increased the levels of Na+, K+, CEC and ESP, whereas for Ca2+, BS and H++Al3+ the increase was only observed in the coated pits. The coating of the pits with plastic film intensified the salinization and sodification of the soil. The application of calcium in addition to increasing its soil content, attenuated the damaging effect of sodium, reducing ECse, Na+ and ESP. The high calcium level fertilization 60 kg ha-1 is recommended for the cultivation of passion fruit in Entisol with a low calcium content.