Salinity and Compost Amendment Impact on AmidaseActivity in Rhizoshere of Tomato and Beanplants

Abstract

The aim of this study was to disclosed the activity of extracellular enzyme (amidase) in vertical and horizontal developing directions of rhizosphere (0-5 and 5-10) cm . The plots experiment was performed in Agriculture college / Al-Qadissiyah University for the spring season 2013 ,the sandy loam soil was used and cultivate Tomato (LycopersiconEsculentum mill) and Bean (Phaseolus Vulgaris L.) plants under salinity levels (without salinity , 6 , 8 and 10) dS.m-1 and compost levels (0,10 and 20)T.h-1 , and their interactions completely randomized design (CRD) was used with six replicates, and the means of treatments were compared by L.S.D test 5% level . The results were summarized as : The enzyme activity were increased with increasing of the adding compost level 20Ton.h-1 and its interactions with salinity levels . The enzymes activity were varied in rhizosphere development directions and the plants were differed in the site of highest activity , the enzyme activity in horizontal rhizosphere development direction was higher than the vertical direction . The enzyme activity in tomato rhizosphere was higher than bean rhizosphereinall rhizosphere vertical and horizontal directions . The high inhibitor percent of enzyme activity was at the level of 10 dS.m-1 salinity and the lowest was at the 6 dS.m-1. The inhibition percent were increased in vertical direction of rhizosphere developing (5-10)cm in tomato plant. The adding compost levels were varied by increasing or decreasing of enzyme activity according to rhizosphere development and it sites .