a b s t r a c t
Establishment of buffers and incorporation of trees and shrubs are believed to improve soil quality and
thereby improve water quality from grazed pasture systems. Although enzyme activities and water
stable aggregates have been identified as measurable soil quality parameters for early responses to
changes in soil management, the literature lacks information on those parameters for grazing systems
with agroforestry buffers. The objective of this study was to examine the activities of fluorescein diacetate
(FDA) hydrolase, dehydrogenase, -glucosidase and -glucosaminidase, the percentage of water
stable aggregates (WSA) and soil organic carbon and nitrogen as soil quality parameters for grazed
pasture and row-crop systems. The study consisted of four management treatments: grazed pasture
(GP), agroforestry buffer (AgB), grass buffer (GB) and row-crop (RC). The WSA was determined by
wet sieving method while the enzyme activities were colorimetrically quantified using a spectrophotometer
in laboratory assays. Soil organic carbon (SOC) and total nitrogen (TN) contents were also
determined. Two soil depths (0–10 and 10–20 cm) were analyzed for all treatments. The row-crop
treatment showed significantly lower activities compared to all other treatments for -glucosidase and
-glucosaminidase enzymes along with lower WSA. The dehydrogenase activities were significantly
higher in GP treatment compared to RC treatment. The FDA hydrolase activities were not significantly
different among treatments. Surface soil revealed higher enzyme activities and higher WSA than the subsurface
soil. The treatment by depth interaction was significant for -glucosidase and -glucosaminidase
enzymes. The soil organic carbon and total nitrogen data strongly supported the results of enzyme
activities and WSA. Implications can be made that perennial vegetation enhances organic matter accumulation
in the soil, has minimum disturbance to the soil and will have positive impacts on the
ecosystem.