Soil Structure
Poor soil structure can be a hidden challenge, preventing optimum root penetration into the soil profile, compromising nutrient uptake and hindering drainage. Compaction can be an issue on both grazing and cropping fields.
Current research has highlighted that compaction caused by cattle trampling can lead to a loss of total grass silage dry matter yields by 500 kg/ha; tractor wheeling’s can reduce yields by 200 kg/ha*.
Its worth taking a look at soil structure across the farm and identifying and rectifying any problems. The Visual Evaluation of Soil Structure (VESS) guide provides a good starting point and can be easily carried out on the farm, and more information is included in the Valuing Your Soils booklet.
*February 2013. Presented at British Grassland – Profitable and Sustainable Grazing Systems: Moving Forward with Science Conference. Based on Work carried out a Crichton Royal Farm, Dumfries-shire.
Soil pH
Poor soil pH makes it harder to maximize yields, irrespective of the amount of fertilizer applied. Although lime can be seen as an expense, soil pH outside the target range could already be costing your business in terms of:
- Poor crop utilization of expensive fertilizers
- Restricted crop uptake – grazing ground at a pH of below 5.5 means half of your applied nutrients may be unavailable for uptake by the growing crop
- Yield penalties
- Increased diffuse pollution risks and loss of greenhouse gases from the farm
A report from the Scottish Farm Advisory Service has found that almost half of Scotland’s farms could be suffering from low pH levels. A study of 273 soil samples from around the country showed that almost half of the soil samples had a pH below 5.8, one-third were between 5.8 and 6.2, and only 18 percent were above pH 6.2. This agrees with recent research which shows overall UK grassland production could benefit from improving soil pH status. The full report is available on the Scottish Farm Advisory Service website.
Video resources
A guide to the Visual Evaluation of Soil Structure (VESS)
Dr. Bill Crooks, a soils and drainage expert, is on a farm to demonstrate how to undertake a Visual Examination of Soil Structure (VESS). In this video, he is in a grassland field that is due to be ploughed and planted in crop as part of the rotation but not before time as can be seen by the VESS. Dr. Crooks then moves into a neighbouring grassland field to compare the soil structure with the first field, again using a VESS.