EFFECT OF DIFFERENT SOURCES AND LEVELS OF POTASSIUM ON GROWTH, YIELD AND CHEMICAL COMPOSITION OF FABA BEAN PLANTS

Abstract

A pot experiment was undertaken out door at the farm of Faculty of Agric. El-Mansoura Univ. during the winter season of 2014 to investigate the effect of different sources of potassium fertilization on vegetative growth, chemical composition and yield of faba bean plants (Vicia faba L.). Ten treatments were arranged in a complete randomize block design with 3 replicates, thus, the total number of the experiment was 30 pots as follows: (Control treatment: without K-fertilization), (50 kg K2O.fed-1 as potassium sulphate (RD), 37.5 kg K2O.fed-1 as potassium sulphate, and 62.5 kg K2O.fed-1 as potassium sulphate) and (50 kg K2O.fed-1 as potassium thio sulphate (RD) (137 lit.fed-1), 30 kg K2O.fed-1 as potassium thio sulphate (82 lit.fed-1 ), and 70 kg K2O.fed-1 as potassium thio sulphate (191.8 lit.fed-1 ) as well as (200 kg.fed-1.feldspare, 100 kg.fed-1 feldspare and 300 kg.fed-1 feldspare ). Results reveale that the mean values of vegetative growth parameters as (plant height, fresh and dry weight as well as leaf area), fresh weight of pods and seeds, N, P, K, Fe in plant foliage and seeds were increased significantly with increasing rates of potassium fertilizers. The highest values were recorded with using 62.5 kg K2O.fed-1 as potassium sulphate. As for the; EC and pH of soil was decreased with increasing rates of potassium sources. The available nutrients in soil (N, P, K and Fe) increased significantly with increasing rates of potassium fertilizers. The highest available values of N, P, K and Fe ppm in soil were recorded with using 62.5 kg K2O.fed-1 as potassium sulphate.