Abstract

Abstract: Northern state, Sudan is extremely affected by desertification and Salinization processes, there for this study aimed to investigate an effective method to improve the salt affected soil. Two field experiments were carried out in two successive seasons ( July 2005 – June 2006 ) at Dongola University farm, in the North State to investigate the effect of irrigation frequency ( 7 and 14 days ) and farm yard manure (M0 , M1 , M2 , andM3 ) on salt leaching undersaline – sodic soil . The experiment was designed in spilt – plot design , where irrigation frequency was assigned in the main plots ( 6x28m) and farm yard manure were the sub – plots ( 6x7m) .The total cultivated area was 1342m2 for each experiment. The quantity of water applied was estimated according to Jensen andHaise (1963 ) . The total water quantity was the same by the end of the season. In general , the result indicated that irrigation frequency of 7 days enhanced salt leaching from the root zone. Generally , the reduction in electrical conductivity ( ECe ) and sodium adsorption ratio ( SAR ) due to irrigation frequency was more effective in 7 day irrigation interval as compared with 14 – day irrigation interval . the data obtained indicated that the addition of FYM 10 ton/feddan, significantly degreased the (ECe) and the (SAR) and leached them below the root zone. So, we can conclude that the efficiency of salt leaching is markedly affected by irrigation frequency and yard manure.