The first step to growing good grass is to assess what is already there and make management decisions based on this.
Do you know your soil?
Healthy soils are the foundations for healthy grassland. To know what is going on in your soil you need to go out into your fields, dig a hole and examine it. The key features of healthy soil and the ways to assess it are explained in more detail on the Swarm Hub. Click on the links below to explore:
Do you monitor grass growth?
You need to know how much grass is growing so you can make informed decisions about grazing and so you can minimise grass waste.
Grass growth is determined by a range of factors including soil health and temperature, light, water, nutrient availability and variety of species within the sward. Most grasses have evolved to withstand grazing by having growing points near ground level which will quickly regrow after defoliation. When grass growth is at its highest, a new leaf is produced every 4-5 days, in winter it can take up to 30 days to grow a new leaf. There are two stages to grass growth:
- Vegetative growth – leaf production, best for grazing
- Reproductive growth – production of flowers and seed heads, less productive grazing
The only way to really know how well your grass is growing is to measure it. You can either measure sward height (in cm) or kg of dry matter/hectare (KgDM/ha). Sward height is usually measured in centimetres and using a sward stick, but you can use general items such as your welly boot or a bit of pipe. It doesn’t matter as long as you are consistent. (Click here to order a FREE sward stick from EBLEX).
To measure KgDM/ha use a sward stick that shows this unit or a rising plate meter (a guide to using plate meters can be found here).
|Stock||Grazing period||Pre-grazing (cm)||Pre-grazing (kg DM/ha)||Post-grazing (cm)||Post-grazing (kg DM/ha)||Set stocking (cm)|
|Sheep||Spring turn out||8-10||2100||4-6||1600||4-6|
|Beef||Spring turn out||10-14||3000||5-7||1600||5-6|
Things to consider:
- Speed of re-growth after cutting
- Can the sward still support the same numbers of livestock it has done in the past?
- Are patchy or poached areas developing?
If your grass is achieving an annual yield of 12 tonnes of DM/ha, or more then it is doing really well. If it is falling between 5 – 8 tonnes of DM/ha/year then you should be thinking about rejuvenating your existing sward LINK.