Soilborne diseases and pests cause major losses in field. For some vegetable and fruit crops, soilborne diseases, weeds, and nematodes have been partially controlled by soil-applied pesticides, including methyl bromide, chloropicrin, and metham.
Soil solarization, a nonchemical technique, controls many soilborne pathogens and pests.
Transparent polyethylene plastic placed on the soil during the hot summer months (when the day is long, sky is clear and the air tempature is high) increases soil temperatures to levels lethal to many soilborne plant pathogens, weed seeds, and seedlings (including parasitic seed plants), nematodes, and some soil residing mites. Soil solarization also improves plant nutrition by increasing the availability of nitrogen and other essential nutrients.
Maximum soil heating occur when the plastic is close to the soil; ThereforeIt, it is important that the area to be treated is level and free of weeds, plants, debris, and large clods which would raise the plastic off the ground. The soil should be disked, rototilled, or turned over by hand and raked smooth to provide and even surface and to help water penetrate and moisten the soil profile.
Soil must be moist for maximum effect, moisture not only makes organisms more sensitive to heat, but it also conducts heat faster and deeper into the soil. Soil can be moistened by pre-irrigation or by drip or furrow irrigation following laying of the plastic. With machine application of the plastic, irrigation water may be run underneath the tarps in the tractor-wheel depressions, which act as shallow furrows. Irrigation under the plastic usually controls pests slightly faster and to a greater extent than when irrigation is done before the plastic is laid.
Benefits of Soil Solarization:
- Disease control.
- Weed control.
- Nematode control.
- Increased plant growth response.