Growth, nutrient accumulation and nutritional efficiency of sunn hemp in function of nutrient omission

Abstract

The inadequate supply of nutrients in sunn hemp comprises nutritional requirements and efficiency, causing a decrease in the growth and inducing specific nutritional disorders. For this reason this research sought to evaluate the effect of N, P, K, Ca and Mg restriction on nutrient accumulation, nutritional efficiency, plant growth and characterize the visual symptoms of nutrient deficiency in crotalaria. The experiment was conducted in a greenhouse in pots with constantly aerated nutrient solution. The experimental design was completely randomized with six treatments, corresponding to the complete nutrient solution (all nutrients) and omission of N, P, K, Ca and Mg individually, with three repetitions. The plant species used was sunn hemp juncea. When the particular nutrient deficiency symptom was defined, collection of the corresponding treatment plants was carried out to evaluate the stem diameter, leaf area, dry matter production of the root, shoot and entire plant, accumulation of N, P, K, Ca and Mg in the root, shoot and entire plant, efficiency of absorption and utilization of the nutrients studied and characterization of the visual deficiency symptoms of nutrients during the experimental period. The restriction of N, P, K, Ca and Mg in the cultivation of sunn hemp caused a reduction in plant growth and characteristic visual symptoms of nutritional deficiency of the respective nutrient. Deficiency of N and Mg caused greatest losses in growth of sunn hemp in relation to the other macronutrients due to lower capacity of the plant to use these nutrients in the production of dry matter when grown in the restrictive environment.