Impact of slurry application method on phosphorus loss in runoff from grassland soils during periods of high soil moisture content

Abstract

Previous studies have reported that the trailing shoe application technique reduces phosphorus (P) in the runoff postslurry application when compared to the traditional splash-plate application technique. However, the effectiveness of the trailing-shoe technique as a means of reducing P losses has not been evaluated when slurry is applied during periods of high soil moisture levels and lower herbage covers. To address this issue, three treatments were examined in a 3 × 4 factorial design split-plot experiment, with treatments comprising three slurry treatments: control (no slurry), splashplate and trailing-shoe, and four slurry application dates: 7 December, 18 January, 1 March and 10 April. Dairy cow slurry was applied at a rate of 20 m 3 /ha, while simulated runoff was generated 2, 9 and 16 days later and analysed for a range of P fractions. Dissolved reactive P concentrations in runoff at day two was 41% lower when slurry was applied using the trailing-shoe technique, compared to the splash-plate technique (P < 0.05). In addition, P concentrations in runoff were higher (P < 0.05) from slurry applied in December and March compared to slurry applied in January or April, coinciding with periods of higher soil moisture contents. While the latter highlights that 'calendar'-based non-spreading periods might not always achieve the desired consequences, the study demonstrated that further field-scale investigations into the trailing shoe as a mitigation measure to reduced P loss from agricultural soils is warranted.

Slurry Acidification as a Solution to Minimize Ammonia Emissions from the Combined Application of Animal Manure and Synthetic Fertilizer in No-Tillage

“…The combined use of SF and manure might be an option to enrich the manure while decreasing manure application rates, making it possible to cover more agricultural lands, enabling access to manure/slurry where it is a scarce resource, to improve application operation efficiency and also, to decrease over-fertilization with phosphorus (P), as normally occurs when using manure [12]. In addition, it might be a solution to enhance SF efficiency.…”

Effect of increasing the time between slurry application and first rainfall event on phosphorus concentrations in runoff

“…This study was conducted with repeated rainfall simulations at 2, 9, 28 and 49 days. Low-emission slurry spreading by trailing shoe was compared to splash plate application over repeated simulated at 2, 9 and 28 days (McConnell et al, 2016). The splash plate method resulted in higher initial P concentrations on day 2 (>1.5 fold the DRP concentrations from trailing shoe).…”

The Beast from the East: impact of an atypical cold weather event on hydrology and nutrient dynamics in two Irish catchments

“…These disproportionate losses were not correlated with increased sources but corresponded to soil saturation and storm runoff. Propensity for overland losses during high rainfall is observed throughout the literature (Doody et al, 2010;McConnell et al, 2016;Schwab et al, 2017) and…”