IMPROVING THE QUANTITY AND QUALITY OF SUDANGRASS GROWN IN SALT AFFECTED SOILS USING GYPSUM AND BIO-FEUTILIZATION

A field experiment was carried out at El-Serw Station Damietta Governorate Agric. Res. Center during two summer seasons of 2014 and 2015. The present investigation aimed to increase fodder productivity of sudangrass (sorghum bicolor (L.)var. sudanense( piper cv.)under such saline soil and investigate the possibility of partial replacement of N-fertilizer by the application some soil amendments. The amendment gypsum was added at 4 ton fed-1 or without and three N-fertilizer levels (30, 60, and 90 kg fed-1) under two bio- fertilization treatments (inoculation and uninoculation). The obtained results were summarized as follows: 1-Application gypsum to salt affected soils promotes the use efficiency of N-fertilizer which was reflected to plant height, fresh and dry yield and gave the better nutritive content as compared to without gypsum.  In this concern, the application of 4 ton gypsum fed-1 gypsum and 90 kg N fed-1 with inoculation gave the highest increments of yield quantity and quality parameters under study. 2-Gypsum decreased soil pH and EC, both soluble and exchangeable sodium. However, increased soluble and exchangeable calcium. 3-Application of N fertilizer at 60 kg fed. -1 with bio-fertilizer gave no significant results with those obtained when plants were fertilized by the high level of 90 kg N      fed. -1 alone without bio-fertilizer. 4-Inoculation with nitrobein was resulted significant increases in plant height, fresh and dry yield, and crude protein content compared to untreated. The results could be concluded that the application of 4 ton gypsum fed-1 and 60 kg N fed-1 with nitrobein inoculation was the best treatment to sudangrass under the condition of salt affected soils for increasing fodder productivity and quality as well as improving soil characters.