Solarization – Eric McLenaghan
Solarization is the practice of covering an area of soil with a clear plastic which allows sunlight to pass through. This will then heat up the soil temperatures to levels that are lethal to weeds, and other soil pests. Solarization is a useful technique to use on an area of soil in which past weed and pest management techniques have had no effect, as it can reduce weed germination in the year of use and later years. It can be used just about anywhere, providing the area receives an ample amount of sunlight, but may only be able to be used in smaller scale production, particularly planting bed rows.
Since water helps to conduct heat, before covering the soil it is best to moisten it a bit. If using on row beds, it is best to orient the place in north-south orientation to keep the edges of the plastic warm, and prevent weed growth here. This technique should be done during the hottest months of the year such as June, July, or August. The soil should be covered from a period of 4-6 weeks for maximum effect. Finally, before moistening and covering, it is a good idea to mulch the soil and remove any debris.
A person should make sure they have adequate sunlight and heat before attempting solarisation, as in areas that do not get hot enough, this may act as a greenhouse and stimulate weed germination. The plastic that should be used must be completely clear to allow maximum light penetration, and for maximum effect the edges of the plastic should be buried in the soil.
The costs associated with solarisation are basically the cost of the plastic and the time and labour involved in covering the area. There is also the fact that covering should take place during the sunniest and warmest time of the year. This means that production will be halted during the period when plants are at the highest rate of growth.
I my opinion solarisation is a viable option for small scale growing operations. Larger fields are obviously much more difficult to cover with a sheet of plastic, then a garden plot. I also believe that since it is not a major control agent since it costs a reduction in productivity, but could be useful in a rotation to different areas of a garden.
McSorley R., and K. G. Harsimran. 2010. Introduction to Soil Solarization. Online. Available: https://edis.ifas.ufl.edu/in856 Accessed: March 12, 2014.
B. Hanson. 2013. Soil Solarization. Online. Available: http://www.organicgardening.com/learn-and-grow/soil-solarization Accessed: March 12, 2014.