Articles
BASAMID GRANULAR – A HALOGEN-FREE SOIL DISINFESTANT
Dazomet is formulated as a solid micro-granular preparation and thus offers advantages in terms of handling and environmental impact.
Basamid® Granular has a low mammalian toxicity and the data on user toxicity do not indicate a particular risk.
The toxicity to bird species is low, but there is a moderate toxicity to water organisms like fish.
Field studies have shown, that the initially strong effects on populations of soil-dwelling organisms like earth- worms and soil arthropods are reversible.
Like all other soil disinfestants Basamid® Granular has to be incorporated into the adequately cultivated moist soil, where it is degraded to mainly MITC, CS2 and other volatile products.
The degradation intermediates are toxic to nematodes, fungi, bacteria, insects and weeds.
The half-life of Dazomet in moist aerobic soil is less than 24 hours.
The end products of degradation are bicarbonate, nitrate and sulphate, which can be considered as plant nutrients.
The environmental fate of Basamid® Granular was followed in a lysimeter study under field conditions for two years using 14-C-labelled Dazomet.
Less than 1 % of the initially applied radioactivity was recovered in the percolating water and up to 60% of this radioactivity was identified as bicarbonate.
Neither Dazomet nor the main degradation product MITC could be found in the percolating water, in the soil or in the plants growing on the treated soil.
These results confirm that degradation of Dazomet in soil is rapid and leads to complete mineralization.
The volatile breakdown intermediates of Dazomet do not pose a hazard to the stratospheric ozone layer.
Emissions possibly resulting from the high application rates of chemical soil disinfestants can be minimized by modifications of the application techniques, e.g. by covering the treated soil with plastic sheets (tarping). A further advantage of tarping is seen in the chance to reduce the application rates of BasamidR Granular at least in some uses.