Effects of slurry application methods on soil faunal communities in permanent grassland

We studied the effects of two slurry manure application methods, broadcasting manure slurry (MB) and manure slit injection (SMI), on soil faunal communities 1 week and 4 or 5 weeks after application in the spring of 2002 and the summer of 2003. No effect on total numbers of Enchytraeidae and nematodes was found. Enrichment opportunistic nematodes (CP1) significantly decreased in the MB treatment, resulting in a significantly higher Maturity Index. In the SMI treatment the Maturity Index was unchanged. Effects of manure application methods on earthworms depended on soil moisture and season. Under wet conditions abundance of earthworms, especially epigeic earthworms, decreased significantly in the MB treatment. In the summer of 2003 total earthworm numbers, and the fraction of epigeics, decreased after SMI. Due to the drought in this period, abundances of epigeic earthworms were already low and possible significant effects of the different manure application methods were therefore hard to interpret.