Getting the most out of grazing is critical part of many dairy businesses.
James Ingles, head of agriculture at Barenbrug UK, outlines five steps on managing grass to get the highest yields.
Step 1: Walk your fields
Look carefully at any areas of grassland. If grass is an unhealthy shade of yellowy-green or if there is water lying on the surface after rainfall, there could be a soil structure problem.
Left untackled, this could affect production and persistency levels later in the year causing the sward to fill up with weed grasses. This in turn will decrease yields and affect spring growth significantly.
Check for areas of bare ground where grass is thin or where weeds have already taken over – especially common in feeding areas and around gateways.
Look also for high and low areas where bare patches might occur, and damage caused by pests such as rabbits and moles.
Step 2: Look below the surface
If you think there is a problem, examine soil structure. Basic nutrient tests are inexpensive and will help you understand the levels of essential elements present.
Digging a hole to examine the top few inches, which are so important to the grass lifecycle, is also advisable – and doesn’t cost anything.
Where there are signs of compaction, use either a sward lifter or aerator to alleviate the problem.
The choice of tool will depend on the depth of compaction. Shallow compaction – up to 20cm – can be corrected by slitting the field with an aerator.
Deeper compaction is best treated using a sward lifter, which will lift and shatter the soil, allowing deeper root penetration and a healthier soil.
Step 3: Deal with weeds
Tackle weed grasses immediately. They are usually shallow rooted and pull out very easily. If they make up more than 40% of the sward, harrow hard to remove them.
With a sward of more than 70% weed grasses, the best option is to reseed.
Step 4: Prepare the ground
If overseeding is necessary, pick a mixture designed specifically for renovation.
Before seeding, harrow or rake vigorously with a spring tine or chain harrows. This can be carried out by machine or, for very small areas, by hand.
The aim is to remove all dead material including shallow rooted grass and weeds in the base of the sward.
Opening up the sward lets in air and light, allowing clean, fresh growth to come from the base of the plant. It also levels any mole hills and highlights vulnerable parts of the field.
Step 5: Overseeding
After harrowing, use a grass mixture designed specifically for the job in hand.
The best time to reseed is when the ground is moist and warm, and soil temperatures are above 8C.
The ideal window in the UK is typically between April and September, when conditions allow grass seeds to germinate and grow without competing against weeds.
Rolling the ground after sowing helps seed-soil contact to promote germination.
Reseeding in these conditions allows the plant to develop a good root structure that is ready to spread and grow the following spring, so quickly increasing grass cover.