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

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.

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.

Baseline samples

To indicate whether any differences between catchments were due to difference in pasture species, or whether there
were any pre-existing differences between fields, samples from earlier experiments that had been archived were
analysed for a range of elements via ICP. Soil samples were taken in June 2012 in a nested sampling pattern on a 25 m or
50 m grid, to 10 cm. Samples were air-dried, homogenised and stored in a cool location. The archived samples closest to
each corner of each experimental block were analysed where they were available, but where they were unavailable no
alternative sample was taken.

The herbage baseline samples were taken in the weeks prior to the start of the experiment. The samples were snips
taken in a W across the field, which were bulked, air-dried and analysed for a range of elements via ICP. Note that
samples NW653/023 and NW653/024 are not from the field in which the experiment took place but instead represent
the field where the animals were grazing when dung and urine were collected. However, these had the same pasture
mixtures as the experimental fields, and livestock solely grazed a single pasture mixture (‘Catchment’).

Details can be found in the additional information below.