In the higher rainfall areas of Europe, high yields of grass can be grown but there can be difficulties in conserving this for winter feed due to poor trafficability and soil compaction damage. In Ireland, for example, most grassland is grown in regions having rainfall of 800-1400 mm of which about 50 % falls in the forage harvesting period (May-October), so that soils can be quite moist and vulnerable to damage during the harvesting and transport operations.
The aims of the project include :
- improved harvesting and transport machinery,
- more efficient production and utilization of herbage and a reduction in nitrogen requirements,
- reduced soil structure damage and improved infiltration of slurry and water into soils.
In the higher rainfall areas of Europe high yields of grass can be grown but there can be difficulties in conserving this for winter feed where soils are moist and vulnerable to damage from machines during harvesting and transport. The aims are to improve harvesting and transport machinery, to achieve more efficient production of herbage, with a reduction in nitrogen requirements and to reduce damage to soil structure, thereby improving infiltration of slurry and water into soils.
In Ireland, field experiments were established at 2 sites. One with heavy textured, poorly drained, surface water grey soil and the other with clay/clay loam topsoil overlying a gravelly clay loam subsoil. Treatments simulating harvest traffic were applied to the plots and measurements were made of soil properties, herbage growth and quality. Where soil is moist, initial results suggest that the use of high ground pressure transport equipment for grass harvesting affects soil structure and can reduce crop yields substantially compared with low ground pressure equipment and zero traffic. In Scotland, a site was established on an imperfectly drained clay loam soil. A slurry taker was modified to give a track so that slurry could be applied without wheels making contact with the treatment area. Initial results suggest that soil compaction reduced the volume of soil macropores considerably and the rate of slurry infiltration was many times lower than on uncompacted soil. The uptake of nitrogen available in the slurry was greater in the uncompacted than in the compacted soil and first cut dry matter yields were up to 30% greater on the uncompacted plots.
The project will study existing harvesting systems and modify them and/or develop new harvesting/ transport systems aimed at reducing ground pressure, improving trafficability and limiting soil damage. Controlled traffic trials will be conducted at two locations to compare the conventional and novel low ground pressure systems for their effects on forage yield and quality, nitrogen utilization and soil structure. The effects of different degrees of soil compaction on water and slurry infiltration into soil will also be examined.
EH26 0PH Penicuik