Arnolds Hill Farm, Slebech, Haverfordwest
Focus Site Project: Undersowing maize for environmental and economic benefit
What will be done:
A 5 hectare (ha) field situated on a slope and sown with Augustus maize has been chosen as being likely to suffer from soil erosion if left uncropped over winter. The overall aim will be to establish a root network by harvest time to stabilise the soil and carry traffic, reducing any possible run-off and erosion at the time of harvest and over winter.
Four trial plot areas will be established by undersowing into the standing maize crop at the end of June/early July using a Zocon tine drill:
Plot 1 – Italian ryegrass (IRG) blend sown at 7kg/ac (17.3kg/ha). IRG is chosen as it is vigorous and economical to use as a short rotation crop.
Plot 2 - Straight tetraploid perennial ryegrass sown at 8kg/ac (19.8kg/ha). This has the potential to graze better quality grass if left through to the next season (leafier and will head later). It will last longer than IRG and this trial will investigate how well it competes under the maize canopy.
Plot 3 - Italian ryegrass and winter vetch sown at 12kg/ac (29.6kg/ha). With the vetch being a legume, it has the ability to fix nitrogen for the following crop. It is also a high protein plant, therefore, either grazed or cut, it will boost the protein content for livestock.
Plot 4 – IRG and Berseem clover sown at 8kg/ac (19.8kg/ha). This option provides for rapid biomass cover and the ability to quickly fix nitrogen. The clover is an annual therefore can be grazed out/cut out or left to keep fixing nitrogen. Protein quality of the grazed or silage grass is again boosted by the clover. Although this clover is not very frost tolerant, this can represent a bonus when direct drilling the following spring crop, as most of the canopy will be gone by this time.
Following the maize harvest, anticipated in late September, grass cover will be allowed to bulk up and grazed by tack sheep from November onwards with the number of grazing days achieved recorded.