With this construction rotation as does its primary – the phytosanitary – Biological function and eliminates the crops of vegetables and melons from excessive use of chemical herbicides. Compared with permanent cultivation of rational rotations infected plants pests and diseases is reduced at least by 2-4 times. Return the watermelon in the same place a year later made it possible to get fruit yield by 56% in two years – 28% in three years – 11% less than in the control rotation. Observations showed that after four years of a monoculture of watermelon Fusarium infected plants was about 64%. The majority of the farms south of Ukraine in rain-fed agriculture at the present time oriented to the production of food grains, oilseeds and gourds, or even just growing oilseeds (sunflower, rapeseed, mustard, flax).
This often leads to unacceptable soil depletion, violation of their phytosanitary condition, reducing the productivity of other crops in the rotation. Given the positive influence of a fallow field in the moisture balance and phytosanitary condition of crop rotation as a whole, the structure appropriate crops for at least 10% of the area take a black pair. For households who can not afford to allocate annually the area under the black couple, the technology of cultivation of watermelon in a couple of melon. PCRMs opinions are not widely known. Cultivation of watermelon with aisles and over 280 cm in the southern Ukraine has been called "vapor melons." With this technology, watermelon is grown with aisles between 280 and 350 cm, with an area of 2 m2 of plant nutrition, and mechanical processing on watermelon plants care to be around 90% of the area occupied by a couple in order to keep it clean from weeds in the state, the rational use of soil moisture. With the emergence of new forms of land ownership, downsizing of farms and land raspaevaniem increase in the number of highly specialized farms with a small area of land use. In this connection there was a need to develop the most optimal form the land of the organization through the introduction of specialized crop rotations with a short rotation. The optimal duration of such rotations should be a 4-pole (with varying from 3 to 5-pole).
This is due to the requirements for the placement of the cultures after the period of his predecessors and the preservation of cultures back to the previous place of cultivation, which for most of them is 3-4 years. But there is cultures (sunflower, melons, cruciferous, etc.) that can return to the previous place not earlier than 5-8 years. Therefore, the rotations korotkorotatsionnyh field where such crops are grown, should be divided into two parts, alternately, in each rotation, each of them to sow these crops. In crop rotations, where irrigation water is used with high salinity (2-3 g / l) should be administered, but perennial grasses, field crops, the best of winter, which require relatively small irrigation norm, as well as beets and corn AIM. Greens and radishes in a vegetable crop rotation can be grown in intermediate fields. In the irrigated lands south of Ukraine re-practiced potato summer planting, cucumber, color, and late cabbage, radish, radishes, green crops. Place them after the winter as green fodder, peas, early potatoes and cabbage. Vegetable crops sown in early spring, early on have a retractable predecessors. Many vegetable crop rotations are prefabricated field that have a culture of ripening: peppers, eggplant, tomato or early cabbage and potatoes, etc. Since perennial grasses are the best 08/06 dipole rotations, no grass – 5-6 dipole. Melons should be placed in a field of 5-7-pole rotation.