Effect of pasture composition in cattle grazed systems on soil properties and nutrient cycling: impact on herbage, soil and cattle excreta

Abstract

Full experimental details can be found in McAuliffe et al. (2020), https://doi.org/10.1016/j.agee.2020.106978, and Segura et al. (2023), https://doi.org/10.1016/j.jenvman.2022.117096. The experiment took place on the North Wyke Farm Platform (NWFP), a UK National Capability in SW England. The NWFP is split into a number of self-contained farms (‘farmlets’) that are managed according to different operation philosophies or practices. The NWFP is highly instrumented and monitored, and core NWFP datasets are open and include in-situ water flow and chemistry taken at 15-minute intervals; 15-minute Met measurements; 15-minute soil moisture measurements; 30-minute GHG emissions; soils, crop and botanical field survey data; livestock and crop performance data; and farm operational activities, and contextual information is also available. See https://nwfp.rothamsted.ac.uk/. At the time of the experiment, there were three farmlets on the NWFP with different pasture management strategies. Permanent pasture (PP), a perennial ryegrass monoculture (HS) which was sown with a high sugar Lolium perenne cv. AberMagic, and a white clover/perennial ryegrass mix (WC) with the same ryegrass variety as the HS pasture. The PP and HS pastures received N fertilizer at a standard rate, but the WC pastures did not due to the inclusion of a legume. Fields within a farmlet are cut for silage and grazed by cattle and sheep, with livestock grazing or consuming silage only from one farmlet. This experiment used a single field from each farmlet, chosen as they represent a trio of fields that typically undergo very similar timings in agricultural management, such as grazing by the same species at the same time, as far as is feasible. Within each field there were three experimental blocks each containing six plots (2.5 x 1.5 m). Each of the six plots within a block were randomised to controls or treatments. Treatments were dung, cattle urine, or synthetic urine. The dung was collected from fields within a farmlet, homogenised using a concrete mixer, and refrigerated in sealed barrels until application on the plots. Cattle urine was collected from cattle within a farmlet over the period of a couple of days, bulked, and frozen until application on the plots. Synthetic urine was included as a treatment to investigate the effect of pasture composition on N2O emissions to be tested without the confounding effects of different urine compositions. Three plots within each block were controls. One control plot in each block received no N fertilizer, while the other two plots in the PP and HS blocks were controls plus N fertilizer to replicate the rest of the field; the WC blocks had three controls with no N fertilizer as this farmlet does not receive N fertilizer. In some cases, only one of the two plus N fertilizer controls were analysed for some of the measurements. This dataset contains data on herbage yield; soil moisture; soil physical properties (bulk density, mean weight density, soil loss through 50 µm sieve); soil chemistry (various measures of carbon and nitrogen content, pH and ergosterol); herbage and manure total carbon and nitrogen; micro- and macronutrient concentrations of herbage, soil, urine and manure; and earthworm counts. Urine and manure are characterised before being applied as treatments, while soil and forage samples were taken at various time points from shortly before the application of treatments through to several months later. In the case of the micro- and macronutrient content of soil as assessed by ICP, baseline samples – taken prior to the implementation of the farmlet treatments – are also included