Dataset on soil physical and chemical properties under barley – pea intercropping and monoculture systems in Dundee, Scotland, 2022-2023

Summary

This dataset contains measurements of soil physical and chemical properties at Balruddery Farm, Dundee, Scotland. Soil samples were collected periodically between 2022 – 2023 at different crop growth stages from upper (< 5 cm) and lower (5 – 30 cm) topsoil depths.

These data were collected from a field experiment study designed to examine the short-term effects of barley – pea intercropping systems on soil properties.  Specifically, it involved two barley – pea intercropping systems and their respective monocultures. The experiment was carried out at Balruddery Farm, Dundee, Scotland which belongs to the James Hutton Institute in partnership with the University of Aberdeen. The work was supported by the Scottish Government’s Hydro Nation Scholars Programme through the Scottish Funding Council (Grant number: SF10247-10).

Provenance & quality

Soil samples were analysed for chemical properties at the University of Aberdeen, while soil physical properties were analysed at the James Hutton Institute, Dundee. Instruments were used following standard calibration steps and results were quality controlled.

Related document: Journal paper associated with this dataset can be found at https://doi.org/10.1002/agj2.70275

Supporting documentation

Cropping systems consisted of three monocultures and two barley-pea intercropping systems involving two barley cultivars and one pea cultivar (Table 1). Barley cultivars were 1) Laureate, a high-yielding barley cultivar, and 2) KWS Sassy, a water stress-tolerant cultivar, while the pea cultivar was LG Stallion (Table 1).

Soil was sampled on six occasions over the two years for analysis of the following soil parameters: total soil carbon and nitrogen, volumetric water content (VWC), water retention, dry bulk density, porosity, macroporosity and penetration resistance. There were three sampling campaigns in 2022: pre-tillage (PT) on 29 March, mid-season (MS) on 28 June, and post-harvest (PH) on 22 September; and an additional three in 2023: PT on 21 February, MS on 20 June and PH on 19 September. Samples were collected from location: 56.485°N, -3.114°W. 

Table 1: Description of cropping systems
ID Description of cropping systems
BL Barley (var. Laureate) Monoculture
BL&PS Barley (var. Laureate) and Pea (var. LG Stallion) Intercropping
BS Barley (var. KWS Sassy) Monoculture
BS&PS Barley (var. KWS Sassy) and Pea (var. LG Stallion) Intercropping
PS Pea (var. LG Stallion) Monoculture

Soil cores were weighed at field condition, saturated for at least 12 hours, weighed again, and then placed on ceramic suction plates for at least 10 days to equilibrate the soil to a matric potential of -50kPa, prior to reweighing to obtain water retention. Samples were then measured for soil penetration resistance with a universal test frame penetrometer (Instron model 5566; Instron, MA, USA) mounted with a 50-N load cell accurate to 2 mN at maximum load. Each soil core was penetrated with a 1 mm diameter needle at 30° cone angle to a depth of 15 mm at 0.75 mm increments from the soil surface at a rate of 4 mm min−1. Penetration resistance between 4.5 mm and 9.8 mm depth was averaged as the sample penetration resistance. To bulk density (g cm-3), the soil from the cores was reweighed after oven drying at 105 °C for 24 h. Data are expressed as mass of oven-dried soil per volume of cylindrical core. Soil water content was determined gravimetrically (g g-1) as mass of water in the soil sample per mass of the oven-dried soil and converted to volumetric water content (%) by using the bulk density of the soil sample. Porosity (%) was determined from bulk density, assuming 2.65 g cm-3 as particle density. Thereafter, cores were sieved to 2 mm and the mass of non-soil particles that did not pass the 2 mm sieve is regarded as the stone mass. For chemical properties, samples were sieved using a 2 mm sieve, dried in an oven at 105 °C for 24 h and ball milled before using Dumas dry combustion procedure with a flash combustion elemental analyser (model: NA 2500; manufacturer: Carlo Erba) to obtain total C concentration (g kg-1) and total N concentration (g kg-1).