Electrical conductivity scanning on a Farming Connect demonstration site in Pembrokeshire, has cut costs and targeted fertiliser application.

The EC soil mapping was undertaken on 60 hectares (ha) of land used for growing cereals and 40ha of grassland at Pantyderi Farm, Boncath.

The technique maps precisely how soil properties vary across each field.

Using this information, fields at Pantyderi were subdivided into management zones and these were soil sampled to give a detailed picture to inform variable rate lime, fertiliser and seed sowing rates.

On the arable land this has allowed farmers Wyn and Eurig Jones to capture £720 of savings on lime – instead of applying at a flat rate 170 tonnes at a cost of £5,100, variable rate application maps allowed lime to be targeted where it was needed, reducing the volume used to 146 tonnes.

The farm is now growing a crop of spring barley with variable rate input management, and is working with Farming Connect to compare performance and costs to an adjacent field of barley of the same size and similar soil type variation where inputs are applied at a flat rate.

In areas of the variable rate field where soil is poorer, seed was sown at a higher rate to even out crop yields across the field.

The contractor sowing the seed used digital maps provided on a plug-in stick which connects through his tractor’s GPS system control panel to inform a variable sowing rate drill.

Farming Connect is monitoring crop development differences between the two fields and will compare the yields at harvest.

Cost savings have been captured on the grassland too - at a variable rate, 171 tonnes of lime was spread instead of the 182 tonnes that would have been applied at a flat rate; this represented a saving of £324.

Dr Delana Davies, knowledge exchange executive at Farming Connect, who is overseeing the project, says one 6.86ha field highlighted the value of soil mapping.

“Although the soil classification for the whole field is a sandy silt loam, two of the four zones have soils with a higher sand content while the other two have a higher proportion of silt and clay.

“Should the field average pH have informed flat rate lime applications, lime would have been under applied on two zones while it would have been wastefully applied on the other two zones.’’

Ben Burgess, of Agrii Rhiza, carried out the soil mapping and sampling and produced the management zone maps and variable rate application recommendations.

He says soil mapping means farmers no longer need to take a broad-brush approach to improving grassland and crop yields.

“Farmers are always pushing to get more from their land but to do this they first need to know what their soil nutrient status is and to understand how they can make it perform better for them,’’ says Mr Burgess.

Farming Connect has found a creative solution to the temporary suspension of its on-farm events this summer with a series of live digital broadcasts from its demonstration sites.

These broadcasts will take the events to farmers, allowing Farming Connect to continue its engagement with them during the current pandemic.

For more information visit the Farming Connect website at businesswales.gov.wales/farmingconnect/whats-on