Heaving of Plants

the exposure of tillering nodes and root tops of plants as a result of the alternate freezing and thawing of the soil. The phenomenon is observed in the winter or spring in heavy, nonstructured supersaturated (moist) soils. During freezing, the soil expands in volume, and then during thawing it settles, which leads to eruption of the roots and baring of the tillering nodes. Heaving can also be caused by the ice crust that forms on crops; the plants freeze into this crust, and, when subsequent layers of ice form from below, the plants are pushed up out of the soil. Heaving occurs particularly frequently when sowing is done on soil that has not been sown soon after plowing; the soil then settles after the shoots appear. Heaving damages winter grains, perennial herbs, and other wintering plants. Methods of protection include sowing varieties that have deep-set tillering nodes, sowing in well-worked and sown soil, and packing the soil before and after sowing. Plants that suffer from heaving in the spring, before the soil has dried out, are packed down. In this process the bared tillering nodes become attached to the soil and form new roots.