Nitrate leaching from cut grassland as affected by the substitution of slurry with nitrogen mineral fertilizer on two soil types

Abstract

A field experiment was conducted to find out whether there is any difference in risk of N leaching to groundwater when cattle slurry and ⁄ or mineral fertilizer-N was applied to cut grassland. The experiment was carried out over two consecutive years on two sites (one with a relatively wet sandy soil and one with a relatively dry sandy soil). Treatments were mineral fertilizer-N at annual rates of 0-510 kg N ha )1 year )1 and combinations of sod-injected cattle slurry (85, 170, 250 and 335 kg N ha )1 year )1 ) and mineral fertilizer-N (289, 238, 190 and 139 kg N ha )1 year )1 ). Yield responses indicated that in the short run, 0AE44-0AE88 (average 0AE60) of the slurry-N was as available as mineral fertilizer-N. The total N input from mineral fertilizer and slurry was a worse predictor of nitrate leaching (R 2 adj 0AE11) than the N surplus (i.e. the difference between total N input and harvested N) (R 2 adj 0AE60). The effective N surplus, based on the difference between the summed inputs of the plantavailable N and harvested N, proved to be the best indicator of leaching (R 2 adj 0AE86). Annual N application rates of up to 340 kg plant-available N ha )1 complied with the target nitrate concentration in groundwater of 11AE3 mg N L )1 set by the European Union in both years on the wet sandy soil, whereas on the dry sandy soil none of the treatments did.

The effect of fertilizer and N application rate on nitrogen and potassium leaching in cut grassland

“…Nitrogen rate used was positively correlated (P < 0.05) with sward yield, which in turn was in negative correlation (P < 0.05) with N leaching. Our results are in accordance with the results of Schröder et al (2010), who showed that until the yield increases with increasing N rate and therefore N use efficiency is high, N rate has reducing effect on its leaching. From this result it is possible to conclude that N leaching can be reduced by keeping the grassland high-yielding.…”

“…Bergström et al (2008) suggest that in organic systems, which depend on renewable and natural fertilizer sources N mineralization and crop N demand are poorly synchronized making it more vulnerable to leaching than inorganic fertilizers, especially under the cold and humid climate conditions. Ten Berge et al (2002) and Schröder et al (2010) state that it does not matter much from a leaching point-of-view whether the N requirement is met with mineral fertilizer-N or with plant-available N from manure; it is the quantity of N in the system rather than the source of N, which determines the environmental impact (Watson, Younie, 1995).…”

Nitrate leaching from liquid cattle manure compared to synthetic fertilizer applied to grassland or silage maize in the Netherlands

“…For permanent grassland, it has been established that at the same NFRV, the amount of nitrate leaching is not affected by the N source, whether CAN or LCM (Ten Berge et al 2002;Schröder et al 2010). Therefore, Ten Berge et al (2002) concluded that, on cut grassland, N applications as LCM up to 400 kg total N ha -1 year -1 and more have little effect on residual soil mineral N (SMN) at the end of the growing season, and therefore on the amount of nitrate leaching over winter.…”

Bedrijfsspecifieke mest- en kunstmestgiften op melkveebedrijven : onderbouwingen ten behoeve van de ‘BES’ in 2016-2018

“…Daarvoor verschillen bodems, teeltwijzen en managementcapaciteiten te veel. Uit zowel modelmatig (Schröder et al, 2007) alsook experimenteel (Schröder et al, 2010) onderzoek blijkt dat dit verfijning van normen rechtvaardigt. Het onderhavige BES-project verkent in welke mate sommige bedrijven meer mest zouden kunnen toedienen, al dan niet in ruil voor kunstmest-N. De onderbouwing van de toe te kennen ruimte maakt gebruik van modellen, te weten het WOD-model (dat een relatie veronderstelt tussen N-gebruik van Nbodemoverschot) en de KLW (dat een relatie veronderstelt tussen veestapelsamenstelling, melkproductie en voer-en kunstmestaankopen enerzijds, en mest-en gewasproductie en N-bodemoverschot anderzijds).…”

“…Daarbij moet wel bedacht worden dat het deel van de mestgift dat bovenop de generieke mestgift is toegediend, nog niet in evenwicht gekomen zal zijn met de cumulatieve jaarlijkse afbraak zodat een negatief effect van mineralisatie buiten het groeiseizoen op nitraatuitspoeling nog niet volledig tot uiting gekomen kan zijn (e.g. Schröder et al, 2010).…”