Effect of tillage and compost amendment on turfgrass establishment on a compacted sandy loam

Abstract

Severe compaction of urban soil is a common problem that makes establishment and maintenance of turfgrass difficult. Compaction alleviation prior to seeding or sodding with turfgrass should lead to more persistent cover with reduced labor and maintenance inputs. A field study was conducted to determine the effects of several levels of soil remediation (tillage and tillage with compost amendment) on the establishment and persistence of low maintenance turfgrass grown on a severely compacted sandy loam. Four soil treatments consisting of two levels of tillage (none or subsoiler and Rotadairon) and three levels of compost amendment (0, 152, and 604 m³ ha⁻¹ [0, 61, and 242 ft³ 1,000 ft⁻²]) were applied prior to seeding on September 24, 2012. Initial establishment of plots amended with compost was delayed compared to tillage-only treatment and untreated control, likely due to a C:N ratio imbalance in the compost (C:N ratio = 41). Once the effect of the C:N imbalance had diminished, compost amended plots consistently sustained the greatest and highest quality turf cover. By early 2013 (seven months after seeding), turf quality and cover of the nonrestored plots (control) dropped sharply and remained at an unacceptable level for the remainder of the study. The tillage-only treatment provided acceptable turf quality and cover throughout most of 2013, but decreased to an unacceptable level by July of 2014, suggesting that compaction alleviation may be temporary when tillage is practiced on soil with limited organic matter (OM) content. Both of the soil restoration actions, soil tillage and amendment with compost, decreased soil bulk density, but the greatest reduction in bulk density occurred with OM addition. Compost amendment also improved soil OM content, pH, and nutrient availability. The treatment that produced the greatest improvement in soil properties measured (bulk density, volumetric water content, and nutrient availability) and turf cover was tillage in combination with compost amendment at the highest rate (604 m³ compost ha⁻¹).