The influence of nemagon fumigation on the major nutrients of a fertilized soil

Abstract

The effect of nemagon fumigation on the soil chemistry and microbiology of major nutrients in a fertilized saline soil provided interesting and consistent results. Nemagon at 0.2 ml per kg of soil produced optimum significant availability in ammonium nitrogen with all fertilizer treatments from 30 to 45 days. The effect then declined due to nitrification resulting from the dissipation of the chemical. Though initially toxic a higher dose of the fumigant produced more positive results after 60 days as far as ammonified nitrogen was concerned. The results were in agreement with the nitrite, nitrate and halide transformations. All doses of the fumigant resulted in an initial positive response to phosphorus availability. The influence then declined. The results have been explained on the basis of solubilisation caused by microbial activity. Both in amended and unamended soil potassium availability generally increased with passage of time. Fluctuating responses due to changes in the biological activity were produced with increase in the dose of the fumigant.