Uso de água salina no cultivo da mandioqueira.

Abstract

The purpose of this study was to assess the influence of saline water was applied in increasing irrigation water depths in the chemical properties of the soil and leachate as in the nutritional status, physiological attributes and yield of cassava. The work was conducted in the area of Irrigation and Drainage of IF Baiano, Campus de Senhor do Bonfim, BA (10° 28'S, 40° ll'W and 550 m). The culture installed in the experimental area was cassava. To determine the soil chemical properties and nutritional status of cassava, but also the productivity of the same, the experimental design was completely randomized consisting of seven treatments and three replications, totaling 21 units. To determine the chemical characteristics of the leachate and physiological characteristics of culture, the experimental design was completely randomized consisting of six treatments and three replications, totaling 18 units. The treatments consisted of control (rainfed), a treatment irrigated with drinking water (100% of ETc) and five treatments irrigated with saline water of 3 dS m"1 varying water depths: 110% 120% 130%, 140% and 150% of ETc. The experiments with six treatments did not possess the treatment control. The use of saline water increased the concentration of magnesium and sodium in the soil at a depth of 0,2 m and also the percentage of exchangeable sodium, the ratio of sodium adsorption and electrical conductivity of soil at both 0,2 and 0,4 m; irrigation independently of water quality, decreased the levei of potassium in the soil at both depths studied. In the first six months of cultivation, nitrogen was the nutrient with higher content in cassava leaf regardless of treatment, among the micronutrients, manganese foliar presented higher content. The drainage water coming from irrigation with saline water showed higher leveis of calcium, magnesium, sodium, chlorine, the ratio of sodium adsorption and electrical conductivity. The use of saline water did not interfere with the physiological attributes of mandioqueira. The use of drinking water increased the productivity of mandioqueira.