Pasture- You Never Choose Your Friends But You Always Choose Your Enemies

My small herd of eight goats roam across about fifteen acres of the property, divided into four areas with light weight electric fence tape. They are limited to these spaces in order to leave other areas for establishment of trees since the goats usually enthusiastically prune back any they encounter. Watching how these paddocks are changing over time is fascinating and providing valuable lessons on how to manage spaces and your relationship with the plants you find there. Originally when we had cows the pastures were dominated by kikuyu in the flatter areas and sour paspalum on the slopes, with a few solid monocultures of the tall growing Setaria grass. Given the low feed quality of Setaria grass I was keen to contain and eventually replace these stands. The cows grazed these pastures low before being moved on regularly, greatly limiting the diversity of species present, with almost no forbs (non-grassy pasture plants) and only a couple scattered remnant mature trees. Navigating around the pastures was quite easy and fences could be set up and moved regularly (though the rapid regrowth of grass after cutting meant the lines needed regular clearing).

Shortly before we sold off our last beef herd and changed to goats a mysterious disease spread throughout the entire region. Called “pasture dieback” in caused the death of some grass species but not others. It appears to be a microbe spread by a mealybug that feeds on the crowns of the grasses. We lost our virtually all kikuyu and sour paspalum, but unfortunately the tall Setaria was unaffected. Luckily the few small patches of high quality Rhodes grass and Gatton panic were also spared. In these vacated spaces a luxurious forest of cobblers peg (Bidens alba) sprung up, reaching 2 m tall in places. Although this species has somewhat annoying seed that cling to clothes it makes excellent goat fodder, bee forage and even the geese eat the seeds. I have since learnt how to interact with the cobblers peg, avoiding working it when it has maximum seed capacity, and simply tapping the seeds off with a bamboo pole as I go when I must venture into it. It undergoes a massive pulse every year, springing up to maximum height at the end of summer, then crumbling to a rich layer of organic matter by the spring. The organic matter content and texture of much of my weedy goat paddocks is better than my fairly young vegetable gardens.

 In other places blue top (Ageratum) grew. This species is less palatable to the goats. I was hopeful that the Rhodes grass and Gatton panic would spread and gradually colonise among the drifts of cobblers peg but they appear to be making limited progress. Instead bladey grass (Imperata cylindrica) is gradually forming colonies through its running underground rhizomes. To begin I noticed there was relatively little of it about and that it was pretty poor at starting new colonies from seed, so set about trying to eliminate it with periodic spraying. Hoeing it out is not feasible since the thick running roots are quite deep. As it turns out spraying is also pretty ineffective, with the substantial underground reserves allowing it to come back multiple times. It has now spread enough that any thoughts of eliminating it are long past. I have noticed the goats do eat it. I have also thought about what I want the goat paddocks to ultimately look like. Instead of relying on cobblers peg I am upgrading to the more vigorous tree marigold (Tithonia diversifolia) and tree mugwort (Artemisia verlotiorum), two fodder shrubs that can establish with periodic direct browsing. I also have found Brisbane wattle (Acacia fimbriata) can survive direct grazing since the goats only like it sometimes, with established trees surviving the cow fences being removed, and now self sown seedings appearing in the paddock. I have decided to use the lightly grazed patches of bladey grass and blue top as locations to try direct sowing of Brisbane wattle. I am also planting the tree marigold and tree mugwort in small circles, where the inner space will be relatively inaccessible to the goats, to create locations for establishing other more palatable trees. Bladey grass is pretty non-competitive in these shrub and tree dominated spaces. Even more interestingly it is significantly damaged by trampling with hooves, so dropping piles of tasty cut tree branches on a clump is a way to severely set it back.

All of these species that are growing of their own accord I consider to be friend that chose my farm. Each of these friends have their own host of positive and negative traits that they contribute and there is no such thing as a perfect friend who is all positive. In the early days I bought a large diversity of pasture plant seed (mostly legumes) and distributed them all over the farm. Most of them failed to grow to any meaningful extent, with just a couple of plant appearing in places with an atypical soil mineral balance (such as near imported gravel). It is not feasible to try and force these particular plants to be my friends as they simply do not want to grow here. It is more rewarding to cultivate my relationships with the plants that do want to be my friends.

A new arrival appeared about the time of the die back, a low growing grass called signal grass (Brachiaria decumbens). It appeared on a few boundaries, probably brought in by the slashers that trim our footpath. I watched this new grass with interest. The geese ate the seeds off it where they could. And when some finally turned up in a goat paddock the herd ate it with the right level of enthusiasm, enough to enjoy it but no so much that they wiped it out. The signal grass is now in seed so every time I pass by a clump I gather a handful of seeds that I then distribute into the goat paddocks. A different arrival appeared around the same time called molasses grass (Melinis minutiflora). This is a hairy grass that grows from delicate spreading stems, with pinkish flower heads and a distinct aromatic smell. I read that its presence deters ticks, something of interest since we had a paralysis tick plague last spring. Apparently the aromatic hairs trap tiny larval ticks. I was interested to assess its potential in the goat paddocks, so I distributed some seed and transplanted some runners during a rainy spell. They started to establish small clumps, but something was off. I tried offering handfuls to the goats and they were not interested. Even filling their feeder in the shed with fresh molasses grass resulted in it being totally ignored. On top of that I read that the grass is prone to fire when overgrown.

I weighed up my options. From my establishment experiments it appeared that almost all the clumps were from the cuttings and few from the scattered seeds. That meant it was a primarily vegetative species, with poor seeding capacity. The shallow root system meant it was easy to remove, and a test spraying showed it died rapidly. I decided it was time to make an enemy since this was a battle where the price of fighting to the point of victory was relatively low, while the potential benefits were large. I took my hoe out with the goats on a sunny morning and cleared up the largest paddock in a couple of hours of light work. The bright flowering heads make clumps easy to find at a distance. I now have a couple of more scattered clumps to clear up as well when the rain stops. Also unlike bladey grass the molasses grass is fairly rare in the surrounding area, so once it is eliminated I won’t have reinfestations perpetually arriving from elsewhere.

I have made similar difficult decision to turn the tall Setaria grass into an enemy as well. There were five major infestations when I started with the property. I first tackled two that were choking wet gullies, spraying them out during dry spells and rapidly revegetating with other wetland plants. Next was the smallest upland infestation in an orchard. This was also sprayed out to begin. Mature clumps of Setaria are about 40 cm across with a very deep root ball, meaning they are very physically taxing to remove, tend to regrow readily, and removal causes massive disturbance and erosion. Spraying by contrast creates a deep litter that slows down regrowth of new seedlings. Young Setaria start off very small and take about 12 months to form a large rootball, so can be hoed out at young age. Now the monoculture of Setaria is broken down and other species of weeds moved in I simply hoe out flowering plants every 6-12 months in this space. The second largest Setaria infestation was in the outer goat paddocks and was also broken up with spraying. I have since noticed the goats quite like some Setaria in their diet, so I am content to leave the main stand for them, only removing young Setaria that appear far away from this space. The final Setaria infestation is too large to spray, and is outside the goat paddocks. With this section the aim is to simply allow it to stagnate through lack of grazing or mowing, and plant fast growing shade trees over it such as blackwood wattle (Acacia melanoxylon). There is one large teak tree in this area and in its partial shade Gatton panic naturally outcompete the sun loving Setaria. Like the bladey grass that I briefly went to war with it turns out it wasn’t really an obstacle to my ultimate goals and my energy was better spent pursuing them rather than playing whack-a-mole with a more or less innocent grass.

Machiavelli gave detailed instructions on when to make an enemy. Only make an enemy when you can be assured of victory, and that the victory will bring greater rewards than you will pay in the cost of fighting. Do not go to war lightly or the costs may rapidly outweigh the gains even if you win, and alternative approaches to achieve your goals may be overlooked in the meantime.

A colony of bladey grass, ready for direct wattle seeding.

Molasses grass emerging from the goat paddock

Goats nibbling on a small isolated Setaria before I hoe it out

A self sown Brisbane wattle braving the goats

The orchard Setaria patch, mostly replaced by diverse weeds.

A patch of Rhodes grass doing well down hill from some young icecream beans. I suspect the trees act as a mineral pump as I see this pattern frequently.

Bright green signal grass.

Goats making a snack of Setaria before hoeing, plus molasses grass awaiting its doom.