The effect of nitrogen-sulphur fertilizer with nitrification inhibitor on winter wheat ( L.) nutrition.

The high input of nitrogen is often required in today's agriculture, especially for the most cultivated crops largely involved in human and animal nutrition, such as winter wheat. Nitrogen is a mobile nutrient in the soil, and the high doses of N are often associated with possible losses through volatilization or leaching. One of the possible options to increase nitrogen use efficiency is the application of fertilizers with inhibitors. The main objective of the presented three-year experiment established under the field conditions at the two experimental sites was to examine the effect of nitrogen-sulphur fertilizer (ammonium nitrate sulphate) with the inhibitors of nitrification (IN) (dicyandiamide and 1,2,4 triazole). In addition to the nitrogen content in two forms, this fertilizer also contains sulphur, which can possibly enhance the utilization of nitrogen due to their well-known synergy. The treatments included in the experiment were: 1. Unfertilized, 2. N technology 3. N + S technology and 4. N + S + IN. The total dose of applied N for every fertilized treatment was 159 kg/ha. Treatments 2 and 3 were fertilized with three split doses of N, treatment 4 was fertilized only two times due to the addition of IN (a higher dose of fertilizer in the second application). The results obtained from the three-year experiment showed a significantly higher yield of grain (8.18 t/ha) after the fertilization with N + S + IN in comparison with N + S (7.67 t/ha) and N (7.61 t/ha), which proved the positive effect of IN on nitrogen use efficiency during the vegetation. The differences between qualitative parameters of wheat grain (hectolitre weight, protein and gluten content) were evaluated as statistically insignificant for each fertilized treatment. This similar result is likely due to the IN application, which provided a continuous nitrogen supply during vegetation comparable to the three split nitrogen applications. Thus, our results showed, that the addition of IN to the higher dose of fertilizer applied earlier in the vegetation can provide comparable results in terms of quality to the technologies based on three split fertilizations. The three-year experiment established at two experimental sites has proved, that the application of ammonium sulphate nitrate fertilizers with IN in a higher dose is a better option to the commonly used nitrogen technology, which was also supported by the economic evaluation and the highest net profit.