74 | nzdairy SUSTAINABLE DAIRY » Massey University Much to learn and gain from fodder trees Richard Loader Professor Richard Archer, technologist from Massey University’s School of Food and Advanced Technology (below) , believes fodder trees, like the Mahoe, can provide food for stock while soaking up excess nitrogen with deep root systems. Brad Hosking 027 754 6075 - 24 hours of ce@highlinedairy.co.nz MILKING SYSTEMS ead Specialising in: • Complete Dairy Shed Maintenance • New Dairy Shed Builds • Platform Repairs and Maintenance • Water and Effluent Management • General Engineering • Registered Milking Machine Technician Meat work processing plants www.actionelectrical.co.nz cultivars of natives such as whiteywood. Mahoe, which coppices quite well, was used for exactly this purpose back in our own pioneering times as is shown on a placard in Hollard Gardens in Taranaki. In the far north, banana trees, being plantains might well be suitable and have been successfully used already. Some tree species will be quite wrong in that they will be poisonous or induce abortion. Some will be too slow or quick to age so that they take coppicing less well. Anything that adversely affects milk avour or processability will be problematic. Equally some trees could be therapeutic or may reduce methane emissions. There could be much to learn, but also much to gain and New Zealand could once again lead the way.” Given that tree forage was more widely used only a couple of generations ago, Richard believes there is still plenty of hidden traditional knowledge on the practice. Farmers will reach back and remember what their grandfathers did and what they planted to help dry out pug-prone swales and hollows. And their own valuable experience may inform farmers what leaves cows nd palatable. Richard believes that smart New Zealand dairy farmers can work out how best to increase milksolids per hectare over a year once suitable cultivars, techniques and forage harvesters are available. “A less obvious route by which tree forage could increase farm returns is by lifting shoulder milk volumes across the whole dairy system. More late season milk increases utilisation of the existing manufacturing system for no extra capital investment so that all shareholders bene t. We may not be at peak milk after all – just peak dairy hectares.” • Caveat from Richard Archer: “This topic is beyond my expertise area but within my interest area. Some good, targeted research by proper experts could generate the basis for some real advice. Hopefully this offers a technique for simultaneously limiting nutrient run off, increasing farm returns and building a rural landscape that can help sell top-end consumer dairy products. Throughout much of history, goatherders and cowboys have had to look beyond pasture to feed their animals at times when pasture was lean, diseased, burnt or under snow. One common technique was to lop smaller branches off trees and let the animals munch on leaves and twigs. It is still done in New Zealand from time to time, mainly using willow or poplar, but seldom in dairy systems. Common methods are to plant and grow trees in a woodlot then either cut and carry or allow animals in to graze in the woodlot. Both these techniques demand a block of land of reasonable quality which may need to be taken out of pasture. Professor Richard Archer, a technologist from Massey University’s School of Food and Advanced Technology, believes there might be a better way. For the sake of this article, Richard asks us to approach the opportunity as a thought experiment. If 10% of the metabolisable energy fed on a New Zealand dairy farm came from tree forage, what would we plant where? How and when would we use this forage? Can we raise farm cash surplus this way? Can we exploit nutrients on the farm better than now? What is the environmental impact? Can we flatten seasonality to get better utilisation from our manufacturing investment? Richard believes that New Zealand dairy farmers applying their minds to questions like this will come up with the best way of using tree species for forage in their particular farm systems. “Clearly, we gain most by providing feed when grass is scarce, as for any supplement. Ideally, we can use a forage tree species which also hoovers up excess nitrogen and phosphorous with a big, deep root system. And if we’re going to plant trees, we want to provide more value from those square metres than if we kept them in grass.” How do we do all this? Thinking laterally, Richard suggests we use N-hungry trees or bushes and not legumes. “I suggest we plant fodder trees in long, thin strips — along the bottom of shallow depressions, in the damp strips beside streams and in gully bottoms. Keeping animals out of wooded strips is important to maximise the barrier properties of the strips against surface bacterial and phosphorous run-off. I suggest we use a boom-mounted forage harvester to mow these trees and blow the forage into the paddock for cows to access. It is probably at a time of year when contractors are not too pressed with other on-farm agricultural work.” If we get this right, Richard suggests we will have planted root masses to intercept ground water ows to rescue nutrients otherwise lost to streams and rivers. It may take pressure off limits to nitrogen application to the adjacent pasture. And it will sequester a little carbon, intercept wind and enhance the landscape. The species of tree will no doubt depend on all sorts of things including milk quality and animal health. “I suspect we’ll need to use Salix rst until we can breed up some suitable
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