Common Names: American needle-grass, Uruguayan tussockgrass, Uruguayan needlegrass
Scientific Name: Nassella neesiana
Where in the Succession: Low Fertility Exploiter

Chilean Needle Grass is a perennial tufted grass growing to 1-1.5 m tall. It is native to South America, specifically the southern half of the continent. It prefers temperate and semi-arid climates with at least 500 mm of annual rainfall, but it can also be found in subtropical climates.

It looks like Spear grass, and it belongs to the Tussock family, including Serrated Tussock.

What is it telling me about my landscape?
Chilean Needle Grass is a low-fertility exploiter species.

Where will I find Chilean Needle Grass growing, and why is it growing there?

Chilean Needle Grass is another of our perennial grass species that is very opportunistic, seeking landscapes with limited competition and diversity, using disturbance as its trigger to start growing and journey towards dominance where possible.

We will often find it growing with dominance in landscapes with the following conditions:

• A disturbance event that creates bare ground, whether by overgrazing, drought, fire or cultivation, removing competition and opening up an opportunity
• A pasture mix that is moving backwards in its succession
• Limited to little or no organic matter
• Degraded soils, lacking fertility
• Bare, compacted soils and/or poor soil structure

How can we manage Chilean Needle Grass?

Alter our grazing: The best results in managing Chilean Needle Grass with a regenerative mindset have been achieved by changing livestock grazing patterns in areas with high density. In these situations, people have moved to high or ultra-high density grazing (a large number of animals in a small area), with regular movements followed by adequate recovery periods. This has opened up the opportunity for other species to return whilst starting to cycle the fertility in that area to help stimulate change.

Another potential option using livestock is incorporating other species into the site, especially chickens, which can provide a much higher-impact graze than cattle or sheep. They can also provide additional fertility to the site in the form of manure, particularly when fed an external grain feed source.

Use mechanical intervention: Because of its low palatability, in some situations, it can be difficult to achieve the exact results you’re after with livestock alone. In situations like this, we can use machinery to assist us with the task. After grazing a site with livestock, you can come in and slash or mulch the remaining vegetation, creating a clean slate for the next season of plants and, hopefully, some successional change.

Increase our soil organic matter: Chilean Needle Grass often grows in soils low in organic matter and humus, which fits with its being a low-fertility exploiter. To assist in moving it to the next stage, we can increase our organic matter by promoting more material to the surface of our landscape (as discussed in the previous two options) or by bringing in external sources of organic matter to add to the system.

Improve your landscape’s hydrology: In landscapes where Chilean Needle Grass is growing, it is often lower in soil moisture and hydrologically dysfunctional. We can focus on increasing soil moisture and retaining more water in the landscape. This can be done by increasing ground cover and organic matter to hold rainwater longer, and by constructing level contours to slow, spread, and retain water in your landscape rather than letting it be lost.

Increase our soil fungal levels: Like other weed grasses (Giant Rat's Tail and Giant Parramatta Grass), there is the thought that Chilean Needle Grass has a preference for bacterially dominated soils. To help better balance our soils and push towards a more even balance between fungi and bacteria, we could feed the fungi with foods like complex sugars and proteins, fish hydrolysate, biochar, humic acid, and carbon sources like wood, paper, or cardboard.

How to make the most of your Chilean Needle Grass:

• As a Soil Indicator: Low available phosphorus, little soil humus, bacterially dominant soils, low soil fertility, slightly acidic soils
• Livestock: At certain growth stages, Chilean Needle Grass can provide decent nutritional value for livestock. In a field experiment in the Northern Tablelands of NSW, the crude protein and digestible dry matter of Chilean Needle Grass were measured at 13-17% and 58-66%, respectively, in a grazing system that followed rotational grazing methods6.

In Argentina's Pampas Plains, Chilean Needle Grass is considered one of the most important winter-growing natives for its ability to withstand heavy grazing and drought whilst still providing a high-quality perennial feed source.

Original article credit to Tarwyn Park Training. Sign up to their newsletter here.