Grass Growth
The growth habit of grass varies over its yearly cycle and there are various factors that affect its production levels. Good Grassland Management is required to get the optimum benefit from every square metre of grassland on a farm.
Grass growth is slow at the start of the year, increases to a maximum in May, falls sharply in June, increasing slightly in July and then decreases over the rest of the year. Very little grass growth occurs between October and February. The chief factors that affect its growth rate are sunlight (required for photosynthesis), soil temperature, soil fertilizer level, soil P.H, and moisture content.
- Warm humid weather is ideal for good growth rates. Grass is very slow to grow when soil temperatures are below 5-6 deg C.
- If the soil is too dry the grass plants will suffer from a lack of available water for the plant.
- Very light swards i.e. less then 5cm or very heavy swards do not encourage vigorous grass growth.
- The soil type and depth affect the growth rate as well as the soil fertility and pH levels. Soil tests should be done to see what treatments are necessary to achieve optimum levels.
- The variety of the grass has a large affect on the growth rate as well as the state of the grass i.e. presence of any disease, leaf contamination by soil or slurry.
If grass is grazed very late i.e. October/ November it will have a big effect on the amount of grass available in the Early Spring, due to the very slow growth rate over the winter months. This winter growth tends to be detrimental to the grass is it weakens the root structure of the plant.
Grass that is intensively grazed is higher quality when it regrows. It would have a lower proportion of stem material and more leaf. Grazing or topping to approx 5cm results in a more leafy regrowth and also allows more light to penetrate to soil level thus encouraging the growth of clover. Less intensive grazing results in animals leaving areas of grass uneaten, which results in very strong unpalatable grass being present in subsequent rotations.
Benefits of Clover in a grass sward:
- Removes Nitrogen from the air and can fix about 120kg/ha/year into the soil where it is available for grass to utilise. This is well demonstrated at the Solohead research farm where a lot of clover is grown in the sward and as a result very little chemical fertiliser needs to be applied.
- High in protein and minerals which are needed by growing animals and helps increase the protein in the milk produced by milking cows.
- Is good to grow in June and July when the grass growth begins to slow. This is especially obvious in Aftergrass growing on ground cut for first cut silage.
- Animals grazing a sward that has a proportion of clover thrive better then animals on an all grass sward.
Farmipedia.ie is intended as a handy reference point for Irish farmers.
All information posted here is for your information, however Farmipedia.ie take no responsibility for anything posted on this site.
If you wish to return to the Farmipedia.ie homepage, click on the picture of the bull shown on the top left corner!