The use of photometric test kits for investigations of soil enzyme activities

The objective was to test the applicability of different photometric test k its for the determination of potential and actual nitrification and the act ivities of urease, invertase, and cellobiase in soil. Three water affected grassland sites, influenced by the maritime climate were investigated. The results obtained by the test kits and by standard methods were similar. Soi l organic matter content was found as most important factor determining the enzyme activities on these three grassland sites with similar pH-values. A t the site with the largest soil organic matter content the highest activit ies for urease, invertase, and cellobiase were found. However, this was not true for the nitrification rates.