Successful renovation of poor pasture gives high returns. New pasture is also more palatable and has better seasonal growth. Sowing perennial ryegrass offers the opportunity to benefit from endophytes.
Where do you start?
Pasture renovation is the process of increasing the performance of the pastures on your farm. The first step is to evaluate your existing pasture. Does it meet the needs of your farm business? Could you lift your profits by growing more pasture, or pasture of better quality? Looking at the performance of other properties in your areas will help gauge the potential of your property.
The next step is to identify your poor producing paddocks and prepare a programme to turn them into top performers. The difference can be considerable – typically from 4-5t dry matter (DM)/ha/year.
*Pasture production is measured in tonnes of dry matter grown per hectare per year (tDM/ha/yr).
What is good pasture?
Good pasture gives a high level of MS production for your climate and soil type It has high DM yield when you need it, plus good palatability and high feed value.
Without good pasture yield you can’t feed your cows well – that much is obvious. But it’s also increasingly important to have good yield at the times when it is of most benefit to your system. With new pasture varieties, you can now grow more DM in winter/early spring and summer/autumn which seasonal pattern will be most profitable for you?
Palatability is the term used to describe how much cows like (or don’t like) eating a particular pasture. We can’t easily measure this in objective terms, but we do know certain factors have a strong influence.
- Over-grown spring pasture is often unpalatable.
- Perennial ryegrass with an endophyte like AR1 or NEA2 is significantly more palatable than the same variety with standard (also sometimes called high) endophyte.
- Pastures with good clover content are more palatable than those without.
- Low soil pH reduces palatability – lime solves this.
- High potassium lowers palatability (above3.5%).
How to renovate
Identify the land area and paddocks to renovate, test soil fertility and choose a renovation method that suits your needs. Re-evaluate your management strategies to ensure you utilise the extra pasture grown from renovation and turn it into income, e.g. a higher stocking rate.
How much new grass
Annual pasture renewal varies widely on Australian farms, from 5% to 100% of the property’s land area. How much you sow depends on the performance of existing pastures and the potential gains that can be delivered by new pasture in your system. This decision in turn affects your choice of renovation technique.
The simplest way to identify paddocks for renewal is to compare the DM production of all paddocks on your farm, using your grazing records. If all paddocks are the same size, simply add up the number of grazings/year for each paddock. If paddocks are different sizes, you need to calculate grazings/ha. Don’t forget to include hay or silage crops. Typical pastures are grazed 10-12 times a year. Poor paddocks might give 2 less grazings than average and 4 less than top performing new grass paddocks. A gain of 2 grazing from renovation equates to 3-4t DM/ha and is highly economic. If the difference is larger, even bigger returns can be made.
Test soil fertility - Paddocks selected for renovation should be soil tested before sowing, to ensure optimum nutrient levels (particularly phosphate) and pH. Seek further advice from your fertiliser supplier.
There are 3 main techniques, each offering different advantages. Your choice depends on your situation. Cultivation is the premium method and usually has the best results. It gives excellent weed control, overcomes compaction problems and levels uneven paddocks. But it is slower and more costly, so only limited areas (e.g. 10-15%of the farm) can be done in most diary systems.
Spray-drilling and oversowing costs less and have faster turnaround. If over 10% of the farm needs renovation these techniques are most popular. On a property with a large area of poor pastures they can bring huge benefits quickly. Spray-drilling works well in most situations and gives good long term results. Under sowing suits thin pastures, where bare ground assists seedling establishment. For dense pastures we recommend spray-drill.
If you pastures have hard to kill low fertility grasses like bentgrass, we advise a double renovation for best results. E.g. spray-drill short rotation ryegrass, then follow this with a crop, or spray-drill permanent pasture.
Insects can cause rapid seedling loss at pasture establishment, particularly clover, especially with spray drilling, because surface trash encourages them. AgriCote seed enhanced seed will give protection from insects.
The final step in renovation (and one of the most important) is changing you management to utilise the extra pasture. If you renovate 10 ha and grow an extra 4t DM/ha, your system will produce 40tDM more feed next year. Possible changes could be milking an extra 10 cows, or wintering more cows at home.
|Cultivation||Spray-Drill||Oversowing (no spray)|
|EXAMPLE||Cultivation in spring & sow summer crop
Feed crop over Summer
Spray stubble with Roundup
Light graze 10 weeks later
Allow to regrow (e.g. 7-10 days), & spray with Roundup
Graze 3 days after spraying & drill seed into pasture
Light grazing 6 weeks later
|Hard graze & drill seed into thin pasture
|+ ‘S||Most consistent results
Best weed control
Can level paddock
Can incorporate limes
|Cheaper than Cultivation
Good control of competition with herbicide
Quicker to first grazing than cultivation (e.g. 6 weeks)
|Cheap & simple
Little loss of production from paddock
Short rotation ryegrass (e.g. Arnie) can boost winter-early spring growth
|-‘S||Most expensive (although often costs can be part attributed to crop.
Slower to first grazing (e.g. 10 weeks)
|Less opportunity to correct pH
Won’t fix soil compaction (cultivation needed)
|Doesn’t work on dense pastures|