Leaching of mineral nitrogen in the soil influenced by addition of compost and N-mineral fertilizer

This paper deals with the problem of mineral N leaching from arable lands due to the fertilization method. The influence of different doses of compost (50 and 100 Mg ha−1) and N-mineral fertilizer (35-70-140 kg N ha−1) on leaching of Nmin in a lysimetric experiment with winter wheat. The area of our interest represents the main source of drinking water for the city of Brno and its neighborhoods. To demonstrate the effect of compost and mineral nitrogen addition, the lysimetric experiment was established there. Seven variants of the experiment with different fertilization schemes were studied during two vegetation seasons (2013 and 2014), each with three repetitions. The experiment was carried out in plastic experimental containers of 0.3 m diameter and 0.5 m height. Therefore, each lysimeter was the same size and was filled with 25 kg of subsoil and 25 kg of topsoil. The highest leaching of Nmin was detected in the variant C2 where 140 kg N ha−1 was applied, in both vegetation periods (5.97 kg Nmin ha−1 after the first vegetation period and 17.02 kg Nmin ha−1 after the second vegetation period). The positive effect of compost application (individually or in combination with the mineral N) on decrease in mineral N leaching was found during both vegetation period in comparison with variant C2. The highest doses of compost (100 Mg per ha) significantly decreased the concentration of mineral nitrogen in the soil eluate in both periods (3.03 kg Nmin ha−1 and 5.79 kg Nmin ha−1, respectively), by 197% and 293% in comparison with variant C2. There is evidence that the application of compost has a positive effect on the reduction of Nmin leaching