Is Laying Plastic Sheeting Useful in Field Management? Common Practices Explained in One Article

Do you know what the black plastic commonly seen in fields is for? Why do farmers lay a layer of black plastic? What are the benefits of doing so? Do you know? Let's take a look together.

The presence of silver-black plastic sheeting is often seen in fields, with one plot after another completely covered to prevent weeds from spreading; for farmers this is a convenient and cheap practice. At noon the temperature of the plastic sheeting reaches as high as 78°C, and the non-breathable plastic sheeting clings tightly to the soil, not only causing plant roots to rise upward, but even easily causing fibrous root burn and excessively high soil temperature.

Chen Xingzong, director of the "Soil Crop Doctor Hall," points out that field moisture evaporates when heated, but because the plastic sheeting blocks it, the moisture concentrates under the plastic sheeting, and in the process it also carries nutrients upward. "With both moisture and nutrients, plant roots do not want to root downward, and so they gather at the soil surface." When cultivating crops, soil drainage must be done well, and water and oxygen must be allowed to penetrate into the deeper soil, managing an appropriate environment: "You want the soil surface to not have so much water, while the deeper layers have water and oxygen." Roots follow the water; as long as such an environment is managed, the roots will of course go downward.

Chen Xingzong states that soils are divided into clayey soil and sandy soil; clayey soil is finer, easily retains moisture, and warms up more slowly; sandy soil easily loses moisture and, after exposure to sunlight, more readily reaches temperatures that harm crops. When sandy soil is combined with laid plastic sheeting, as soon as it is exposed to sunlight and the temperature rises, the crop is like having a fever; the roots and the rhizosphere microorganisms are damaged, and the crop easily wilts and ages.

Although laying plastic sheeting has many disadvantages, farmers' habits are hard to change, and Chen Xingzong also suggests that at least a PET bottle be placed under the plastic sheeting, together with foliar fertilization and manual weeding.
Now you know, right? Doing this does not only have benefits but also drawbacks, so you must use scientific methods.