Since ancient times agriculture is one of the main productive activities of human being. It continually provides vital human food, livestocks feed supplies and industry with raw materials.
In all ages farmer attached special importance to climate and weather. Even in ancient times, he tried to predict the weather with various signs , from which all his being depended. Drought, dry winds, frosts, heavy rains, storms, black storms and other phenomenas often destroyed crops and caused great distress.
The whole history of the development of agriculture has shown that crop rotation like agriculturally-founded order of crop rotation on the fields in time in combination with fertilizer, tillage systems and the proper organization of seed production is the basis of a rational system of agriculture, which provides intensive use of land, a progressive increase in crop yields. Proper crop rotation in the grass crop rotation makes it possible to make better use of nutrients and moisture of the soil, improves its physical properties, being an effective way to combat weeds, diseases, plant pests and combats climate change.
Science and practice proved that one of the main conditions for continuous improvement of crop yields, livestock of development and improvement of its productivity is correct and creative application of grassland system of agriculture. Water and food are the basic elements of fertility reaches its greatest expression in the firm structural soil and sowing of perennial legumes to form fertile soil structure can not be replaced.
The effect of the right grass crop rotation will start revealing fully not immediately. It takes some time before all of the fields will pass through the perennial grasses and soil will be restored and conditions of fertility will be created.
Positive results from the perennial legumes can be obtained in the case if their seedlings will be uniform with an extensive root system. Under the thick cover of barley, oats, wheat, perennial legumes heavily shaded, causing reduced rate of photosynthesis. With the increasing of density of plant of cover crop, they consume more water from the soil and in the absence of rain they dry up biggest part of the ground to a considerable depth. At this time the poorly developed plants of perennial legumes do not have time to get their roots deep enough and get to the area of dry soil. As a result, their growth and development slows down, there is a massive loss of seedlings of perennial grasses, and therefore pure crops of them had a significant advantage with coating, especially on a pure steam when heavily clogged land passed through well-crafted fallow, in subsequent years, when crop rotation wiil be applied correctly and with proper farming techniques they can get a high yields of cultivated crops. Pure steam, as a precursor, can play a positive role only if the soil cultivation there is soundly and throughout the growing season it will be located in a clean condition from weeds.
With sufficient rainfall under the cover of cultural perennial legumes developes poorly, but at the time of its harvesting cover crop can grow even above it.
Perennial legumes, like other crops, severely dry up the soil during the growing season for the crop formation. However, this does not give grounds to assert that the introduction of grass crop rotation struggle for moisture decreases. The powerful development of the root system of perennial legumes effect positively on the creation of structural soil, which is supported by the best air-water regime for the subsequent crop rotation.
Term of using of perennial legumes (alfalfa, clover, sainfoin, goat’s rue) in field crop rotation is important and with proper treatment of the soil its structural condition will not deteriorate.