Effect of timing of cattle urine deposition and pasture composition on nitrogen leaching losses

Abstract

A lysimeter experiment using undisturbed monoliths from a stony silt loam soil was carried out to quantify the effects different pasture types on N losses from urine applied to soil on different dates. Three pasture types were tested: (a) perennial ryegrass (Lolium perenne)/white clover (Trifolium repens) (PRG/WC), (b) perennial ryegrass/white clover/plantain (Plantago lanceolata) (PRG/WC/P) and (c) Italian ryegrass (Lolium multiforum)/white clover/plantain (IRG/WC/P), with four different urine applications dates (late summer, early autumn, mid-autumn and late autumn).Cattle urine was applied at the equivalent of 700 kg N −1 ha −1 . There was a significant reduction in total amount of nitrate (NO 3 − -N) leached under the PRG/WC/P (14% reduction) and IRG/WC/P (24% reduction) compared with the PRG/WC. High NO 3 − -N leaching losses were found at each urine application date (>181 kg NO 3 − -N/ ha), suggesting there may be higher than expected N leaching losses when urine is deposited onto shallow stony soils, during warmer months (late summer and early autumn). There was no significant interaction between pasture type and urine timing on NO 3 − -N leaching losses.

Implementing plantain (Plantago lanceolata) to mitigate the impact of grazing ruminants on nitrogen losses to the environment: A review

“…A free‐draining soil may allow rapid leaching and so a shorter residence time of N in the root zone could reduce the potential for root exudates to alter N transformations. Talbot et al (2021) suggests that the smaller reduction in N leaching observed in their lysimeter study may be due to the shallow stony soil used compared with the deep silt loam and fine sandy loam soils used by Welten et al (2019) and Carlton et al (2019), respectively.…”

“…In similar work, Welten et al (2019) observed reductions in N leaching of 15% when urine collected from dairy cows grazing a PR‐WC pasture was deposited on lysimeters containing PL monoculture in summer (relative to ryegrass); this increased to 50% when the urine was deposited in winter. Talbot et al (2021) also examined the timing of urine deposition (from cows grazing PR‐WC) on lysimeters with swards containing 25%–35% PL and found reductions in N leached of 14%–24% compared with lysimeters under PR‐WC, irrespective of timing.…”