The Effect of Manure and Compost on Soil Chemical Properties and Availability of Exchange Cations in a Saline Sodic Soil

The utilization of organic amendments in the reclamation of saline-sodic soils can reduce the necessity for the application of chemical Ca+2 sources. In this research, soil leaching experiments were conducted in CRD as split factorial. The main factors were 1) amendment type including manure and compost, 2) amendment rate including 1, 3, and 5 percentage w/w, and 3) leaching stage with 5 levels including without leaching, once, twice, three times, and four times leaching, every time with one pore volume and with 30 days’ intervals. All columns were incubated for 30 days after the addition of amendments and then were leached. The parameters in each column were studied in three depths as a subplot. After 120 days, EC and ESP of soils amended with both types of conditioners reduced under 5 dS m-1 and 15%, respectively. After 150 days, the exchangeable K and Mg were reduced by both conditioners. Exchangeable Ca increased significantly in both amendments at the end of the 5th month. The efficiency of 1% by weight of two conditioners in improving the salinity and sodicity characteristics of soils was the same as other rates. There was not a significant difference between leaching by 3 and 4 pore volume in both conditioners in the most of parameters. In leaching treatment with three pore volumes using 1 percentage w/w of manure and compost, soil EC decreased by 80% and 71% and soil ESP by 44.5% and 35%, respectively.