126 Survey of equine pasture best management practices and soil fertility in southeast Pennsylvania

Abstract

Proper pasture and grazing management can increase nutritive forage yield, decrease operational costs, and reduce nutrient and sediment runoff. However, management can be challenging in suburban areas where pastures may be small and overstocked. This study assessed pasture health and best management practices (BMPs) on suburban Pennsylvania horse farms. Participant farms (n = 28) in counties adjacent to the Philadelphia metropolitan area were recruited via social media, and 2–3 pastures/farm (72 in total; primarily used for grazing) were evaluated between November, 2019 and January, 2020 via soil testing, the USDA-NRCS Pasture Condition Score Sheet (PCSS), and the Penn State Equine Pasture Evaluation Disc (EPED). Farm managers were also surveyed about their pasture management practices. Pasture soil pH, soil nutrient, PCSS, and EPED data were transformed to normality and analyzed with linear models, with p-values adjusted for multiple comparisons by Monte Carlo simulation. Fixed effects included farm purpose (private or commercial); lime, fertilizer, and/or manure application; and whether the farm practiced rotational grazing. Covariates included total number of horses, number of hectares per farm, stocking rate, and farm. Mean ± s.e. pasture size was 0.68 ± 0.07 ha and mean stocking rate was 3.6 horses/hectare. Only 14% of farms had performed a soil test in the last 3yr, and less than 20% applied lime or fertilizer in that period. Three quarters of farm managers allowed horses to graze pastures to under 7.6 cm in height, and 54% reported using rotational grazing. Mean pasture soil pH was 6.18 ± 0.04, with 86% of pastures below optimum range. Soil pH was lower for pastures on private farms ( P = 0.06), and on fields where no lime ( P = 0.05) or fertilizer ( P < 0.01) was applied in the last 3yr. Mean soil P was 41.7 ± 4.0 ppm, with 50% of pastures below and 20% above optimum levels. Soil P was higher for pastures on personal farms ( P < 0.01), and fields with spread manure ( P < 0.01). Mean percent desirable and total vegetative cover scored via EPED were 56.0 ± 2.3 and 66.1 ± 2.8, respectively. Pasture health scored using PCSS was greatest for pastures where rotational grazing was used ( P = 0.03), although this effect did not influence percent desirable cover ( P = 0.68). Both PCSS and EPED scores were positively correlated (r = 0.571; P < 0.01) and both increased with decreasing stocking rate (r = −0.424; P < 0.01 and r = −0.294; P = 0.01, respectively). In summary, there appears to be low-to-moderate adoption of pasture BMPs among surveyed horse farms. Results of this study may be used to target educational programming for horse owners in suburban areas.