| Soil enzymes are considered sensitive indicators of soil health but are not well understood in tillage-intensive vegetable systems. The activities of soil enzymes involved in nutrient cycling (β-glucosidase, β-glucosaminidase, alkaline phosphatase, dehydrogenase, aspartase, and L-asparaginase) were evaluated during 6 yr of commercial-scale production in five organic vegetable systems in Salinas, CA. The systems differed in yard-waste compost inputs (none or 15.2 Mg ha–1 yr–1), winter cover crop frequency (annually or every fourth year), and cover crop type (legume-rye, mustard, or rye). Large differences in cumulative organic matter input (7.4 to 136.8 Mg ha–1) from compost and cover crop shoots affected soil enzyme activities. With exception of aspartase,... |
