Comparative study of using different nitrogenous sources as substitutions of mineral-n fertilizers on growth, some physiological and chemical aspects and yield and its quality of spinach.

摘要

Two pots experiments were carried out at the Faculty of Agriculture, Minoufiya University in 2007 and 2008 seasons to study the response of spinach (Spinacia oleraceae cv. local) to nitrobein as biofertilizer, compost and FYM as organic fertilizers alone and also in combination with ammonium sulphate as mineral-N fertilizer (0, 30, 60, 90 and 120 kg N/fed.). The obtained results cleared that, most studied characters of growth, photosynthetic pigments, total soluble sugars, total carbohydrates, total phenols, minerals (N, P, K and Fe) as well as yield and its quality, showed a significant increase by the application of mineral-N up to 90 kg N/fed., nitrobein and compost fertilizer. Application of mineral-N at 120 kg N/fed. caused a significant decrease in all previous studied aspects compared to control plants. Application of mineral-N had a significant increase in nitrate accumulation of spinach leaves. The lowest values of nitrate concentration and the highest values of total phenols and foliage yield were obtained in treatment of nitrobein at 30 kg N/fed. The highest values of protein and Fe were recorded in plants treated with compost plus 120 kg N/fed. Generally, inoculation of spinach seeds with nitrobein was more pronounced for all studied characters than compost or FYM. The use of nitrobein and compost with 30 and 60 kg N/fed. gave the best results of growth and yield and its quality. All interactions exerted highly significant influences on all traits under study except for number of leaves/plant. So it could be recommended that, the best economic treatment was N application at 30 kg N/fed. with biofertilizer (nitrobein) or organic fertilizer (compost) at 60 kg N/fed., which may reduce N-fertilizer application and increase yield without increasing of nitrate accumulation in leaves.