Effects of soil compaction and moisture on the growth of Juncus tenuis

Abstract

Juncus tenuis Willd. is a warm-season, perennial weed of turfgrass. In wet and compacted soils, it is well documented, yet little is known regarding the interaction effects of compaction and soil moisture on its rooting and foliar growth. A greenhouse experiment examined the effects of soil compaction and moisture on the above-and belowground growth of J. tenuis. The experimental design was completely randomized with a 3 × 3 arrangement with four replications and two runs. Factors included soil compaction (bulk densities of 1.56, 1.77, and 2.00 g cm -3 ) and soil moisture (10.9, 27.9, and 59.6% volumetric water content). Juncus tenuis was transplanted into pots, acclimated for 7 d, and subjected to the treatments for a 10-wk period.Foliar growth was harvested every 2 wk and root growth was destructively assessed. Cumulative foliar and root biomass varied in response to compaction and soil moisture; however, no significant soil moisture × compaction interactions were detected. The effect of compaction on foliar and root biomass accounted for 15 and 12% of the explained variation, respectively. Increasing the bulk density from 1.56 to 2.00 g cm -3 reduced foliar and root biomass by 29 and 40%, respectively. Soil moisture accounted for ≥84% of the variation in foliar and root biomass. Increasing the soil moisture from 10.9 to 59.6% increased foliar and root biomass by 150 and 230%, respectively. The results suggested that cultural practices that prioritize soil moisture modification while alleviating compaction may reduce the presence of J. tenuis within maintained turfgrass.