ANBAR JOURNAL OF AGRICULTURAL SCIENCES

Abstract

This study was conducted to evaluate the interactive effect of different levels of agricultural sulfur, organic matter source and compaction on the biological oxidation of sulfur, through studying the variation in some soil chemical properties during different incubation periods.
A factorial experiment was conducted according to a complete randomization design with three replicates. to know the effect of three agricultural sulfur levels (0 , 1 , 2) gm so.kg-1soil (S0 , S1 , S2) respectively, with three organic matter treatments those without organic matter addition, dried alfalfa and cow manure which added in one level 6 gm c.kg-1soil (C0 , C1 , C2) respectively . and soil compacted to reach three levels of bulk density 1.25 , 1.35 and 1.45 Mg.m-3 (B1 , B2 , B3) respectively. All the treatments was incubated at 28  2 C0 for 15 , 30 and 45 days (T1 , T2 , T3) respectively with maintenance the soil moisture content for all treatments at about 50% of the available water by weight methods through every incubation period. Some chemical properties was evaluated which included electrical conductivity (ECe), soil reaction (pH) and amount of available sulfate and phosphorus in the soil.
The results obtained from this study could be summarized as follows :
1- The addition of sulfur significantly increased ECe, SO4= and available P in the soil with supremacy S2 in decreasing soil pH.
2- Addition of organic matter (C1 , C2) caused an increments in the average of all examined parameters except the pH which was decreased significantly. But C1 showed higher effected than C2.
3- The soil compaction levels B2 showed significantly higher effects in compared with B1 and B3.
4- The interaction between S, C and B treatments showed the highest effects on tested parameters after 30 days of incubation at S2C1B2 treatment.