|Nitrogen soil surplus per ha - Derogation farms
Nitrogen soil surplus decreased in 2021
|In addition to the farm surplus, all nitrogen added and nitrogen removal at farm level also largely determines the soil surplus. The nitrogen soil surplus on farms in the derogation monitoring network also depends on the nitrogen added via deposition, fixation (leguminous crops) and mineralisation, and on nitrogen removal via gaseous losses. The nitrogen soil surplus on farms in the derogation monitoring network was in 2021 on average 144 kg/ha and has not been this low since the existence of the derogation monitoring network (which started in 2006).
Nitrogen soil surplus has never been this low before
The average nitrogen surplus on the soil balance in 2021 was 144 kg nitrogen per hectare. That is 22 kg/ha less than in 2020, and 32 kg/ha lower compared to the long-term average. Over the entire period from 2006 to 2021, the nitrogen soil surplus shows a declining trend. The spread between farms is large for all years. In 2021, 25% of the farms in the derogation monitoring network realised a nitrogen soil surplus below 89 kg/ha, while the 25% farms with the highest nitrogen soil surplus were above 185 kg/ha. The nitrogen soil surplus was highest in all years in the Peat region as a result of the high calculated nitrogen added via mineralisation in this region (average 91 kg/ha in 2021). In 2021, the nitrogen soil surplus in the Peat region was on average 203 kg/ha. The nitrogen soil surplus was lowest in the Loess region and the Sand-250 region with an average of 119 kg/ha. The Sand-230 region and the Clay region were in between with a nitrogen soil surplus of 122 and 139 kg/ha respectively. Over the entire period from 2006 to 2021, four of the five soil type regions show a declining trend in the nitrogen soil surplus. Only in the Loess region there is no downward (but also no increasing) trend.
Nitrogen deposition and nitrogen fixation increased in 2021
In addition to the added items that are included in the calculation of the nitrogen farm surplus (feed, fertiliser, livestock manure, other organic manure, animals and other), the calculation of the nitrogen soil surplus also takes into account the nitrogen added via deposition, nitrogen fixation via leguminous crops and mineralisation on farms with peaty and/or wetland soils. In total, this amounted to 52 kg/ha in 2021 compared to 47 kg/ha in 2020. The nitrogen added via deposition on farms in the derogation monitoring network has decreased on average from 31 kg/ha in 2006 to 17 kg/ha in 2020. In 2021, the deposition increased to 19 kg/ha. The input as a result of nitrogen fixation by leguminous crops was 12 kg/ha in the early years of the derogation monitoring network, from 2010 it is about 8 kg/ha and from 2013 it is 6 to 7 kg/ha. On derogation farms in the Peat region, the nitrogen added due to mineralisation of organic soils varied from 80 to 95 kg/ha in the period 2006-2018, and amounted to 91 kg/ha in 2021. In the other soil type regions, mineralisation played a much smaller role. In 2021, this concerned 18, 6, 4 and 0 kg/ha respectively in the Sand-250 region, the Sand-230 region, the Clay region and the Loess region.
Nitrogen removal steady due to gaseous emission
The nitrogen removal via pasture, stable and storage and manure application emissions amounted to an average of 61 kg/ha in 2021 on farms in the derogation monitoring network compared to 64 kg/ha in 2020. The gaseous emissions from manure application on the one hand and from stables and storage on the other hand were in 2021 21 and 39 kg/ha respectively. The gaseous emission from pastures was only 1 kg/ha. In the period 2006-2021 the total emission varied from 52 to 67 kg nitrogen per hectare, showing an increasing trend. The total emissions in 2021 were lowest in the Loess region with 47 kg/ha and highest in the Peat region and the Clay region with 66 and 65 kg/ha respectively.