The Hidden Costs of Solarization

Solarization Comes With Hidden Costs


In order to determine the effects of solarization on crops, researchers measure the amount of soil heating caused by polyethylene in three soil depths. This can be compared with the temperature in non-solarized soil at 10 cm. Soil heating can affect plant growth, yield, and pest control. Moreover, a solar panel can reduce energy bills by as much as 30%. However, solarization is not without its costs. These costs are usually hidden in the initial investment.

Biosolarization releases toxins

In California, biosolarization is used to improve soil fertility and control nematodes. Researchers conducted biosolarization in a nine-day period, at high temperatures and concentrations of organic acid biopesticide. Soil fertility was measured periodically, and the results showed a substantial increase in nitrogen, potassium, and total carbon in the first year of biosolarized crops. In contrast, biosolarization did not increase the number of nematodes, although the study found no evidence of any toxins in the soil.

In addition to releasing natural products from soil, biosolarization can also increase soil temperatures. In one study, compost was used to raise soil temperatures. Similar results were obtained with green manures from cover crops. However, tarping of soil amended with high carbon inputs can lead to an accumulation of organic acids, which are toxic to many soilborne pathogens. Biosolarization may be a useful tool for pest control, but more research needs to be done before its application.

Process takes 4-6 weeks

During this time, you should prepare the area where you want to solarize by raking off any existing weeds and debris. Then, you should till the area to improve the penetration of heat from the sun. After tilling, you must remove any debris or loose stones that may rip or tear the plastic cover. This is essential in order to ensure that the plastic will not tear easily. It takes 4-6 weeks to complete the solarization process.

Depending on the type of soil, solarization can take anywhere from four to eight weeks. The temperature can reach up to 140 degrees Fahrenheit in the top 6 inches of soil, and up to 90-98 degrees in the middle two inches. However, the benefits of solarization are seen first in the top six inches of soil. This process should be completed before planting fall crops or lawns in the summer. However, it’s important to note that the process may result in the re-emergence of weed seeds or pests.

Effects on pests

Solarization is an environmentally friendly method for controlling soil-borne pests. Solarization uses tarps to capture the heat of the sun and trap it in the soil. Pests cannot survive in super-heated soil. The solar radiation trapped in the soil is toxic to weeds and other pests, but beneficial microbes will thrive at the high temperatures. Solarization may improve soil health, increasing the availability of nutrients and nitrogen to growing plants. Solarization affects soil the most at the surface of the earth. It decreases at depths of 18 inches or more. Soil solarization is most effective in the upper six inches of the earth.

Solarization had a relatively small effect on lentil and faba bean growth. There was no effect on the number of free-living nematodes in the solarized plots. However, the presence of Sitona larvae, which damage the nodules of these crops, was detected in the soil during early crop development. On average, 18 to 46 eggs per 100 g of soil were found. Unlike most other crops, solarization did not significantly affect Sitona population levels.


A recent initiative in Vermont and New Hampshire has lowered the cost of solar panels through bulk purchasing. The initiative has been a big hit locally, and more than 100 residents from three towns have signed up to get free site visits and quotes. But there are still challenges ahead. For example, the plastic cost for solar panels is still quite high, with the best materials costing about $150 per acre. And even if solar panels are installed, they need to be maintained.

The state government provides 30% capital subsidy, while the National Bank for Agriculture and Rural Development (NABARD) provides a loan for 65% of the total cost. Farmers must pay the remaining 5%, thereby making solarization very affordable for them. The loan from NABARD comes with a six percent interest rate and must be repaid in seven years. Farmers can then draw their power from the grid or inject solar power into the grid. The DISCOM and state government pay the farmers Rs3.5 per kWh for the first 25 years.


After solarization, the area should be cleaned of all vegetation, dead leaves, and debris. Water the soil to a depth of 12 inches before covering the area with plastic. The heat from the plastic will kill the seeds and plants, and disposing of the plastic can become a problem if it is not strong and can break apart easily. It can take up to 6 weeks to decompose. The next step is to remove the plastic from the soil.

If the area you’re covering with solarization isn’t already cleared of vegetation, you can do this before applying the solar panels. Tilling the soil increases heat penetration, and you should also remove any debris that might puncture the plastic. Afterwards, remove any weed seeds that may have survived. To prevent holes in the plastic, you should remove all debris before solarizing. If there’s a chance that you’ll use the treated area for other purposes, consider keeping the solar panels and the soil clean and weed-free.

Soil Solarization

Soil Solarization 101

Soil Solarization

This method uses solar energy to heat the soil. The process is effective in hotter climates, but the effects on soil microflora are less dramatic. It also requires full-day sun for six to eight weeks. Soil solarization requires plenty of sunlight to build enough heat underneath the plastic. If solarization is unsuccessful, the soil will not warm enough under the plastic. For more information, see this article. For further information about soil solarization, read the entire article.

Less drastic effects on soil microflora

Soil solarization is not without risks, however, and is often accompanied by increased plant mortality. The process can disrupt soil microbial communities. Researchers have identified bacteria, fungi, and pathogens that are susceptible to solarization. Although this process is potentially harmful to plant health, there are still a variety of soil microbes that are not completely eliminated by solarization.

Increasing the soil temperature through the addition of a polyethylene sheet can help reduce pest and disease problems. Soil temperatures increased by up to 65% in soils solarized by just 10 cm. Another study aimed to assess the effects of soil solarization on plant health found that solarization could reduce the incidence of tomato damping-off and reduced disease by as much as 83%. In addition, solarization can also reduce the incidence of diseases, like fusarial wilt.

Time- and temperature-dependent

Soil solarization is most effective during the hottest weeks of the year. In inland California, this means late June through August, with good results starting as early as late May in the southern desert. In coastal regions, consistent, warm, fog-free periods may not appear until August or September. However, in most regions, soil solarization can be done in late June through August. The time and temperature-dependent effects of soil solarization are summarized below.

During the four-week experimental period, soil samples were collected immediately after infestation, after incorporation of green manures, and at four weeks after solarization. The percentage of infected disks decreased significantly in all treatments, but solarization was not more effective than green manure in either 1995 or 1996. Soil samples were used to measure the population densities of pathogens and beneficial microorganisms. Soil cores were collected from each plot and were mixed for analysis. In addition, green manures were applied to the solarized plots at 230 or 930 liters ha-1.

Effectiveness in hotter climates

The effectiveness of soil solarization in hotter climates has been proven, with some research demonstrating a decrease in microbial populations and an increase in rhizobial populations. In recent studies, the top eight centimeters of soil reached 54degC after solarization treatment, compared to 45degC in untreated soil. Dwivedi R. and S.K. (1993) also observed a decrease in inoculum of R. solani at 24 cm soil depth.

Soil solarization is an organic, chemical-free pre-planting treatment that is a viable option for farmers in hotter climates. It has been proven to control weeds and soil-borne pathogens and is compatible with organic crop management systems. Although solarization can be expensive, it is simple to implement, suitable for farmers in developing countries, and requires only a short period of crop-free time. Farmers often use soil solarization in conjunction with other methods to get the most benefit from this method.


The adoption of soil solarization is relatively low, but its use is expected to rise over the next several years as ozone depletion bans become more prevalent. This technique is effective in killing many microbes, including weeds and soil-borne pathogens, but can cause negative effects on beneficial organisms, such as fungi and bacterivores, which are necessary for the decomposition of organic matter in the soil.

Soil solarization kills most microorganisms, including beneficial ones. Some of these microbes, such as Bacillus subtilis and Rhizoctonia, are killed by solarization. However, some fungi and airborne bacteria are also killed. It also destroys the seeds of annual weeds. It does not kill root rots. In the case of weeds, soil solarization may be less effective than fumigation.


Soil solarization is a process in which the soil is heated by the sun. Soil temperatures can reach up to 50degC, and even 40degC in warm climates. This heat can be transmitted as deep as 30cm, killing most soilborne pests and weeds. The temperature of the soil is dependent on the amount of moisture in the soil, and the warmer the soil, the more heat it can conduct.

Soil microorganisms are primarily beneficial to plant health and can help monitor soil quality. Enzymatic activities are also considered biosensors of soil health. Soil solarization can affect soil microorganisms, which may result in increased production of beneficial antagonists to plant pathogens. This process can reduce pressure on the soil microbiota by improving the availability of chemical compounds. Plasticulture for soil solarization also has other advantages.

Raised beds

Raised beds for soil solarization work best when oriented east to west, north to south, or both. This is because solarization is most effective on areas with little slope and a southwest or south-facing exposure. Otherwise, the solarization may not be effective or may be compromised by pest control. In order to maximize solarization, the soil must be wet at least 12 inches deep. You can add moisture after you cover the area with plastic.

Before starting the solarization process, be sure to prepare the soil by removing any existing plants, mulch, and sprouting weeds. Ensure the surface is level and smooth; if it is not, you may have to “crown” it before applying plastic. The top layer should be sufficiently smooth to prevent puddles from developing, which will impede the transmission of light. Lastly, ensure that the plastic is strong enough to prevent it from tearing or ripping.