Effect of nematicides on the availaible nitrogen in soil and growth of tomato plants

While studying the effect of application of carbofuran (2,3-dihyro-2,2-dimethyl-7 benzofuranyl methyl carbamate) and oxamyl (methyl N'-N'-dimethyl-N (methyl carbomoyl) oxy-1 thio oxamimidate) in soil on the changes in pH, EC, organic matter, available N and growth of tomato (cv. Marglobe), it was observed that available N increased with the increase in dose of nematicides, i.e., up to 10 ppm in carbofuran and 50 ppm in oxamyl, followed by a decline. After 50 days, there was also a decline in available N and EC of the soil as a result of treatment. However, both the nematicides failed to bring about an effect of pH and organic matter of the soil. The increase in growth of plants in nematicide treated soil appears to be linked with increase in available N.