COMMENT:  There are many reasons why grassland farmers should be monitoring weekly grass growth on their farms.

Primarily the information derived will inform of looming surplus or deficits of grass, putting them in a position to be proactive rather than reactive about their grass supply. Furthermore, measuring weekly keeps the grass manager in control of grass quality, thus offering their animals optimum quality at all times.

A further and hugely rewarding benefit is the facility to compile a ‘Best Paddocks Report’ for the farm.

Most grass measurement software tools will compile and aggregate weekly growth rate date for each paddock on the farm and make this information available in a graphic bar chart format. At a glance it is easy to see the total tonnage grown in each paddock and more importantly, the often large variation in tonnage grown between paddocks.

In the example, pictured below, the red line shows the average tonnage grown/ha across the farm. We can quickly see the paddocks that are performing ahead of average and those that are not. Indeed many such reports that I look at tend to resemble the Manhattan skyline such is the variation in height of the various green bars in the chart. However over time it is possible to eliminate a lot of this variation and of course at the same time shift the average grown, red line, significantly upwards.

Generate_Best_Paddocks_GraphGraph courtesy AgriNet 

Having established the variation in paddock performance, we need to decide what if anything we can do about it. Many farmers assume that reseeding a poor performing paddock will automatically improve its ranking. In some cases it can, however we can’t make a silk purse out of a sow’s ear so to speak.

If one or a number of paddocks are performing poorly consider things such as aspect and soil type, neither of which can be changed. A subtle difference in soil type, undetectable above the ground, can yield a big difference in paddock performance.

What can be changed or improved? What about drainage – is poor drainage limiting performance, particularly in spring and autumn? Will reseeding such a paddock be a good investment or prove to be a poor investment decision if the extra grass grown can’t be properly used? We also need to learn how to assess whether soil compaction is an issue and understand the various strategies to overcome this growing problem.

Next consider a soil test. Every farm should have a disciplined soil-testing programme followed by a determined strategy of correcting any imbalances that are revealed. Currently on our farm we test every 3rd January and spend the intervening three years implementing the recommendations. Many farmers seem to forget the second part!

Having satisfied yourself that all of the above are in order, then and only then would I consider sward type. Place a quadrant on the grass and assess how much (if any) Perennial Ryegrass is present in the sward. Look for the red/purple colour at the base of the tillers.  If lack of Ryegrass and/or very old species of Ryegrass are identified as the limiting factor in a paddocks performance then reseeding with carefully chosen grass varieties is a fantastically rewarding option.

If a farmer is informed as to how much grass his/her farm can grown, it is then and only then that appropriate stocking rates can be decided upon. Making these decisions without this information is guesswork.

Image Shutterstock 

Brian Costello has expanded his own dairy farm near Boyle, Co Roscommon from 80 to 200 cows. He also works part-time as a dairy consultant/discussion group facilitator, specialising in dairy expansion. Brian can be contacted via e mail on [email protected] or on Twitter @BrianCostello_