An Innovative Approach: the Use of Di-nitrogen Tetroxide for Soil Fumigation

The effectiveness of di-nitrogen tetroxide (DNTO) as a substitute for methyl bromide in controlling soil-borne nematodes, fungi and bacteria was evaluated. Application of DNTO to soil packed into columns resulted in a reduction of the bacterial population by three orders of magnitude within 1 h, and a complete elimination after 2 h. The same treatment resulted in the destruction of all fungi and nematodes within 10 min. The most effective treatment (30 min for bacteria elimination and 10 min for nematode and fungi elimination) was achieved in soil with a low moisture level (4%), at a pumping rate of 0·1 ml/min DNTO. In a single microplot trial, using 300 g/m2 DNTO, a significant reduction of nematodes was observed. Lack of phytotoxicity of DNTO was demonstrated using tomato plants. In addition, at the above-mentioned soil moisture and DNTO levels, the DNTO is readily converted into nitrate. Hence, the use of DNTO can supply a considerable part of the nitrogen fertiliser requirement of the treated crops and only a small fraction of it is liberated into the atmosphere.