A mix of urea with nitrification and urease inhibitors and calcium ammonium nitrate for winter rapeseed

For three years, 2010- 2012, the winter rapeseed "Californium" was fertilized using nine kinds of N-fertilization, which included control (zero N), urea with nitrification inhibitor (ALZON (R) 46), urea with urease inhibitor (UREAstabil), calcium ammonium nitrate and pure urea. The N-fertilization methods used were monitored by means of fourteen parameters. The best two variants included 45 kg N applied in October and 90 + 65 kg N in March in the form of urea with urease and nitrification inhibitors (ALZON (R) 46; UREAstabil). By contrast, the separate use of calcium ammonium nitrate and urea with urease inhibitor only in spring (155 kg N/ha) led to low biological activity of the soil. Based on the achieved results, we propose to use a mix of calcium ammonium nitrate (possibly ammonium sulphate) and urea with both inhibitors (urease and nitrification) for N- fertilization of winter rapeseed in autumn (45 kg N/ha) and spring (90 + 65 kg N/ha).