Yield and leaf concentrations of nutrients of melon crop and fertility of soil fertigated with N and K

ABSTRACT The use of fertigation as a means of supplying the nutritional needs of crops is a technique widely used among producers. However, it is necessary to improve this technique due, mainly, to the risks of contamination of natural resources. Thus, the objective was to study the productivity and leaf contents of melon nutrients and soil fertility, which presents a high concentration of potassium, when fertigated with doses of nitrogen and potassium in the irrigation water. Five treatments were arranged in randomized blocks with six repetitions. Treatments consisted of combinations of concentrations, in mg L-1, of nitrogen (N) and potassium (K) applied in irrigation water (0-0), (50-0), (50-54), (0-54) and (100-108). The leaf concentrations of nutrients of melon were evaluated at 35 days after planting, and fruit yield and soil fertility at harvest time. The melon cultivated in soil with a high level of K and basal application of 18 kg ha-1 of N in the foundation did not increase production, when fertirrigated with nitrogen and potassium. Although the contents of K, Fe and B varied between the doses of N and K applied, the plants did not have nutritional deficiency. Fertilizer applications in increasing doses contribute to the accumulation of salts in the soil, increasing the risk of salinization.