Wageningen UR scientists contributed to the Special Edition of Soil Use and Management, journal of the British Society of Soil Science. This special issue (volume 32, suppl. 1, June 2016) is dedicated to the memory of Professor Brian Chambers, Head of Soils and Nutrients at ADAS, who died suddenly on 30th August 2014 at the age of 53.
Professor Chambers was also a member of the Scientific Advisory Board to CATCH-C, a project on sustainable soil management that integrated knowledge from experiments and stakeholders and was commissioned by the European Commission as part of the 7the Framework Research Programme.
Apparent nitrogen fertilizer replacement value
Apparent nitrogen fertilizer replacement values of grass-clover leys and farmyard manure were studied in a long-term (24 years) experiment on a loamy sand soil at Grabow, Poland.
The apparent N fertilizer replacement values of ploughed-in grass–clover ley residues in this study indicate that mixed leys in arable rotations can reduce the N fertilizer requirement of the arable phase drastically. As most fertilizer savings came without yield penalties and the ley was harvested for fodder, this study challenges the notion that (partial) substitution of N fertilizer by biologically fixed N always requires yield or productive land area sacrifices. Mixed leys required considerably larger P and K inputs to compensate for higher P and K offtake in the ley phase, as compared to silage maize. Other benefits of leys may be related to improved chemical, physical or biological soil quality, or to the more gradual release and uptake of N from organic sources than from mineral fertilizer favouring crop growth.
- Ten Berge, H.F.M., D. Pikula, P.W. Goedhart and J.J. Schröder, 2016. Apparent nitrogen fertilizer replacement value of grass–clover leys and of farmyard manure in an arable rotation. Part I: grass–clover leys (pages 9-19).
- Pikula, D., H.F.M. ten Berge, P.W. Goedhart and J.J. Schröder, 2016. Apparent nitrogen fertilizer replacement value of grass–clover leys and of farmyard manure in an arable rotation. Part II: farmyard manure (pages 20–31).
Ammonia emissions from cattle slurries
It has been convincingly shown that low-emission techniques, such as shallow injection, reduce the volatilization loss of NH3. This improves the availability of soil N to crops and increases the yields of grassland, provided that soil compaction is avoided and the use of low-emission techniques is not hampered by the presence of stones or steep slopes. Experimental results do not support the hypothesis that low-emission techniques undermine the ability of soils to provide N to crops by swapping types of N loss. Low-emission techniques may stimulate the production of N2 and thus N2O slightly, but recent review papers underline that this does not call into question the rationale behind subsurface applications such as shallow injection. There are no convincing reasons to question the present views on good environmental and agricultural practices and the rationale behind the current advices and regulations concerning the merits of low-emission application techniques for manure.
- Huijsmans, J.F.M., J.J. Schröder, J. Mosquera, G.D. Vermeulen, H.F.M. ten Berge and J.J. Neeteson, 2016. Ammonia emissions from cattle slurries applied to grassland: should application techniques be reconsidered? (pages 109–116)