Commodity Fumigation License Practice Exam

What is the proper soil moisture level for effective soil fumigation?

1. Wet and muddy

2. Soil should barely retain its shape when squeezed

3. Dry and loose

4. Completely soaked

The correct answer is: Soil should barely retain its shape when squeezed

The proper soil moisture level for effective soil fumigation is when the soil should barely retain its shape when squeezed. This level of moisture ensures that the fumigant can sufficiently penetrate the soil and interact with the targeted pathogens or pests present in the soil. When the soil is at this optimal moisture content, it facilitates efficient distribution of the fumigant, ensuring that it reaches the pest population effectively. Soil that is too dry can lead to poor distribution, as the fumigant may evaporate too quickly without proper absorption, while excessively wet or muddy soil can hinder gas diffusion and limit the effectiveness of the fumigant. In these too-saturated conditions, water can fill the pores in the soil, reducing the space available for gas movement and trapping the fumigants, preventing them from reaching the intended target. This moisture level balances the need for fumigant mobility in the gas phase while maintaining enough moisture to enhance its reactivity with soil organisms, thereby ensuring effective pest management.