A permanent trial with organic and mineral fertilizers in monoculture and two-crop rotation as a basis of sustainable maize production

A permanent field trial with different fertilization variants, monoculture and two-crop rotation was established in 1965 at Rimski ˇSancevi experiment field of Institute of Field and Vegetable Crops in Novi Sad, on the calcareous chernozem soil. This paper analyzes the experiment data obtained in the period 1971–2001. Yield trends were negative in all fertilization variants, due to unfavorable weather conditions during the second sub-period and the occurrence of Diabrotica virgifera in monoculture. Grain yields were higher in the two-crop rotation than in the monoculture. Highest yields and quality were achieved in both cropping systems when manure and mineral fertilized were applied in combination. The application of manure alone showed significant advantages over the sole application of NPK mineral fertilizers. Plowing under of harvest residues in combination with application of NPK mineral fertilizers is an advantageous solution when manure is not available. In addition to optimum yields and top quality, the variants with combined application of manure and mineral fertilizers left the highest amounts of NO 3 -N in soil after harvest. For chemozem-type soils with deep ground water table, where there is no risk of nitrate leaching, the dosing of N fertilizers should be further refined. The NO 3 level after crop harvest, as a criterion of environmental protection efficiency, should be diversified to fit different soil types and different agro-ecological regions.