Potassium Fertilization in Conjuction with Foliar Applied Molybdenum and Humic Substances for Faba Bean

Two field expereriments were carried out on sandy soil at a private farm, at El-Shaarawey Village, El Bustan Region, El Behira Governorate located at lat. 30° 43' 22.01"N, long. 30° 13' 44.50" E. during two consecutive seasons at 2012/2013 and 2013/2014.The study was to assess the influence of appling K as soil addition alone or in combination with K foliar application and foliar applied humic substances (HS) at two rates (1 and 2 g/L) in absence or presence of foliar applied molybdenum (6 ppm) on the yield productivity of faba bean plants (C.V Nubaria 1). The results could be summarized in the following points:Data inferred that molybdenum had a significant promotive effect on weight of pods/plant, 100-seed weight, straw, pod and seed yields. Also, the data indicated that content of  N%,  K% and their uptake , as well as  protein% were significantly increased  due to foliar application of molybdenum .Soil application of the half recommended rate(HR) of K with foliar spray of HS (1 or 2 g/L) or 1% potassium sulphate, irrespective of molybdenum treatments, gave the most positive effect on yield,  its components, and uptake of N,P and K in seeds compared to sole application of  full or half recommended rate with no significant differences in most cases.The highest pod or seed yield as well as weight of pods/plant were achieved by application of 50%-K along with foliar HS (1g/L) while, the highest 100-seed and straw yield were recorded by using HS (2g/L). The interaction effect on the studied characters notably appeared in the triple treatment of K-50% as soil addition with foliar application of humic substances at rate (1g/L) and molybdenum (6 ppm) which was superior to others and achieved the significant effect on 100-seed weight, straw yield,  N%, P% ,K% and protein %, as well as N, P and K uptake.