Effect van toediening van verdunde drijfmest met een zodenbemester op grasopbrengst, ammoniak- en lachgasemissies op zandgrond

Samenvatting

Diluting slurry is a possible option to reduce ammonia emission after application by shallow injection. The dilution of manure and possible reduction of ammonia emissions may lead to higher emissions of the greenhouse gas nitrous oxide (N2O). In 2020 and 2021, a mowing trial was executed at two locations in Overijssel on sandy soil. Two dilutions were used: 1 part manure to ½ part water (1:0.5) and 1 part manure to 1 part water (1:1). This has been compared to applying undiluted manure. In 2021 N2O was measured at one of the mowing trials. In the same years (2020-2021) ammonia emission measurements were carried out at one (other) location during the fertilization season. At eight points in time, the ammonia emission was compared with undiluted and diluted (1:0.5), both applied with a shallow injection. There was no significant (N and DM)yield difference between the objects with undiluted manure and diluted manure (in none of the manure-water ratios). Splitting (diluted) manure over four instead of three cuts led to a slightly lower (significant) yield on average. The differences in total N2O emissions between undiluted and diluted slurry were not statistically significant. The N2O emissions of undiluted and diluted slurry were much lower than those of the nitrate fertilizer CAN. The ammonia emission study did not lead to an effect of dilution on the ammonia emission. No robust emission reduction could be observed over the eight performed experiments. Dit rapport is gra