SW—soil and water: cost-effective pollution control by shallow injection of pig slurry into growing crops

In Europe, new legislation on environmental protection will probably require methods that reduce the emission of ammonia and odour from land spreading of animal slurry. Shallow injection (50–70 mm) of slurry is one of the methods recommended, albeit of higher cost than standard surface application techniques such as tanker broadcasting. The aims of this study were to investigate the agronomic effect of shallow injection of slurry into a growing crop, to examine the available information on the potential cost benefits of slurry–fertilizer utilization in the light of the new legislation and to determine the pollution impact of nitrate and ammonium leaching and ammonia and odour emissions. It was found that shallow injection of slurry into growing winter wheat during spring did not have a detrimental effect on the yield. Odour and ammonia emissions were reduced, nitrate and ammonium leachate levels were unaffected and it was of comparable cost to alternative application techniques that satisfy the requirements of the new legislation.