40 years of stationary crop rotation experiment: fundamental development results for agricultural science and practice
L ong-term s tationary e xperiments a re t he n ecessary i nformation b ase for t he c onducting of s cience o riented arable farming. The research results obtained in such experiments are of great importance not only for solving current issues in agricultural practice, but also for developing strategic global directions for improving agricultural systems and agricultural production in whole. In stationary experiments, it is possible to trace the dynamics of land capacity, soil fertility recovery, including changes of agrochemical, physical and biological properties, the phytosanitary state of crops and soil at different levels of intensification and technology used. This makes it possible to give justified recommendations for farming in enterprises with different levels of production at different stages and in different years with different weather conditions. In the meantime, the information obtained in such experiments can serve as a basis for forecasting and modeling of the most effective technologies and systems of arable farming in future. This can not be fully achieved and achieved with high significance in short-term experiments. The article presents the results of 40-year stationary experiment on the study of different types and kinds of crop rotations for agricultural enterprises of different specializations using different fertilizing systems and levels. Over 20 schemes of field and fodder crop rotations, permanent crops of cereals, legumes and fodder crops have been studied. As a result of long-term field experiments, the possibility of adjusting crop rotations under conditions of farming intensification has been substantiated, intensive crop rotations have been developed for farms specializing in production of milk, beef and pork. The evaluation of crops as predecessors in crop rotations with substantiation for cereals, legumes, perennial grasses and tilled crops in various types of crop rotations is given. The effect of different types and kinds of crop rotations on soil fertility was studied. Application of intermediate crops has been scientifically substantiated and schemes of crop rotations with intermediate crops have been developed.