RESPONSE OF BROADBEAN GROWN IN CLAY SOIL OF BAHTIM DISTRICT FOR BIO AND K-FERTILIZATION

 A pot experiment was carried out on a clay soil taken from Bahtim Agric. Res. Station (AR C), Kalubia Governorate, during the winter season of 2005 to study the response of broad bean plants for Bio- and K-fertilizers. Experimental treatments were: Potassium sulfate, K₂SO₄ (M), nature compost rich in K-content (C) and potassium feldspar (K-bearing mineral, KAlSi₃O₈) (F) ,which added in a solo or in a mixture forms at rates of 50%, 75% and 100% of the recommended dose (R.D) of potassium (24 Kg K₂O / fed.). As well as inoculation seed of broad bean (Vicia faba. L, cv. Giza 843 variety) with or without K-dissolved bacteria Bacillus circulans (KDB).
Seed and straw yields of broad bean and their contents of N, P, K, Fe, Mn and Zn were determined to use as indication for the response of broad bean plants for the experimental treatments.
Data can be summarize as follows
                In general, inoculation with Bacillus circulans gave higher yields of seed and straw of broad bean as well as increasing their contents of N, P, K, Fe, Mn and Zn than under non-inoculation condition.
                Using of any type of K- fertilizer or increasing the rate of application significantly increased yields of seeds, straw of broad bean and increased their nutrients contents comparing with non-fertilized treatment (control). The results of 75% R.D under inoculation were nearest from the results of 100% R.D.
                As for the effects of different types of K-fertilizers on yields of seed and straw as well as their nutrients content, mineral fertilizer type K₂SO₄ (M) was the best treatment followed with (F) treatment, when they added in a solo form. With respect to the dual mixture of K-fertilizers (M+F) followed with (M+C) gave the best effects. While, (F+C) and the triple mixture of (M+C+ F) gave pronounced response on the yield of seed and nutrient^'s contents.