Bipura B. The nitrogen regime and humus state of a typical chernozem soil under different fertilizer treatments treatments treatments in the Left-shore Forest-steppe of Ukraine

The object of investigation - nitrogen regime and humus state, typical chernozem of the Left-bank Forest-steppe zone of Ukraine, ammonium sulphate, gypsum, ammonium (saturated) zeolite,sudanese grass, maize, winter wheat.The aim of investigation - to study the effect ot sulphate salts of ammonia and calcium as well as ammonium saturated klinoptylolit (ammonium zeolite) on the state of the nitrogen regime and humus state in a <<soil-plant-fertilizer>> system and productivity of a light-clayey typical chernozem. Methods of investigation - the research was carried out on the basis of field experiments, partly using a stable isotope 15N. Soil and plant analysis were done in corespondence to the commonly accepted field and labaoratory experimental methods. Theoretical results - peculiarities of the effect of nitrogen fertilizers in conditions of a typical chernozem in the Left-bank Fores-steppe of Ukraine were studied. Practical results - gave the possibility to plan the action of nitrogen fertilize rs as well as to evaluate the expediency of long term combined use of sulphate salts of ammonia and calcium, and one-time application of ammonium saturated zeolite. The novelty - new information on the interdependence between the soil mineral nitrogen regime and humus state was got. Non-traditional ways of optimizing the nitrogen regime in a <<soil-plant>> system as an indispensable condition for preserving favourable humification parameters of a typical chernozem while maintaining a stable positive effect on the yield of agricultural crops was got. Degree of application- research results can be used in working out measures for improving the nitrogen regime and preserving chernoizem soils as well as in the study process of teaching agrochemistry and soil science.Field of application- agriculture.