Now we are in the prime time – Canterbury plains. This area used to be all arable, beef and sheep, but now it’s almost wall to wall dairy.
This is my kind of landscape. Nice and flat to farm on, but a great backdrop.
Having said in a previous blog that I do one visit a day… well it turns out I lied. Today’s first farm is owned by Craige MacKenzie, a fellow Nuffield scholar. He has a 200ha arable block, and right next door a 330ha dairy, with 1200 Friesan/Holstein crosses. All of the land is irrigated. I did look around the dairy, which was fascinating to me. As I don’t have a clue about it though, all my questions were childishly simple and I won’t bore anyone with them here.
The arable farm specialises in seed production, but from a very wide variety of plants. Fescue, ryegrass, festolium, winter & spring wheat, Asian radish, plantain, carrots, onions, chicory, faba beans – and probably more that I have forgotten.
Winter wheat can yield up to 14t/ha, but averages about 12.5. It does however get fed 350kg of nitrogen to get up to this sort of level. Craige would probably describe himself as a pragmatist – he will use whatever method of cultivation necessary to get the best crop. This could be ploughing, min-tilling (tines to 20cm), or direct drilling.
Craige is of the opinion that it is not possible for a farmer to change the levels of organic matter in his/her soil, and he points to a study conducted nearby that has been going for 14 years to support this. I will be seeing the guys responsible for it on Friday so that will be enlightening. He is also in to straw burning (stop hissing at the back), mainly to control slugs, and also to reduce residue and make planting small seeds easier.
Interestingly Craige said to me that people had realised is that by getting rid of animals they made more money, and had an easier life. This sounded pretty much like what would have happened in the east of England 40 years ago, but it turned out to not be strictly true!
Every NZ farmer I have met has had grass and livestock somewhere in the system. Here the leys used for seed production will be in the ground for between 18 months and 5 years, depending on species. Each year they will produce seed, silage and grazing, either for dairy cattle or sheep. Cows pay NZ$27/hd/wk, and sheep NZ$1.50/hd/wk. These relatively long term perennial sections of the rotation can only help with organic matter levels, as the root masses are so large.
In my opinion this effect from the grass probably makes the system sustainable from a soil carbon point of view, although the fact that levels are not building suggest that the input:output of carbon in the soil is in equilibrium. The farm I visited next is towards the other end of the scale in philosophy, and gives a good counterpoint. These two farms gross the same income per hectare, but use very different systems!
David Ward is a pretty well known guy around here – I must have had at least half a dozen people telling me that I should go and see him. He farms 385ha of irrigated land in a single block not far from Ashburton. Again, the focus is almost entirely on seed production: wheat, barley, ryegrass, clover, peas, carrots, beetroot, radish, Pak Choi, spinach… the list goes on.
There is also a massive livestock element, with up to 20,000 lambs and 1,000 deer being finished annually. Some of the lambs are kept throughout the year, although most come in over the winter, where they could graze ryegrass, oats, or some type of brassica.The speciality here is ryegrass seed, and the sheep are as much of a tool for optimising this as they are for meat production. Over winter all the ryegrass is grazed down low, as in the before-and-after picture above. This means it emerges more evenly in the spring, increasing pollination and thereafter yield.
David is a Cross Slot user, which he really values mostly for its versatility; “Most drills work perfectly 80% of the time, this one does 95%”. On the other hand he says “it’s just part of the system”.He is also a man after my heart, who drives around with a spade in the back of the truck. I have never seen worms like this. A spadeful will probably contain 15-20 good sized ones, with countless more little white babies right under the surface. The estimated population is 700/m2.
In 1992 two thirds of the farm was in pasture, and one third cropped. The grassland was measured at 4.5% soil organic matter, and the cropping land, with a 20yr history of ploughing, was 3% SOM. At this point David started no-till, and 9 years later SOM in the same paddock had increased to 5.4%, and it is now nearer to 6%. Obviously this is not a scientific trial, but anecdotally it is an impressive result. Straw is also burnt here sometimes, or sold off-farm if the price is right. Both of these farmers do not believe much is lost when burning residues.
Here is a great comparison. On opposite sides of the road are David’s paddocks, and a farm operated organically – with full cultivation. The photo above shows the difference in structure between the two, which are only about 50m apart. The tilled soil collapsed instantly when dug up,and could be rolled into a worm easily. This was impossible with the un-tilled; it would just crumble apart. I think it is fair to say that the organic soil will smear, compact and crust much more readily.
Such is the improvement in structure and resilience on David’s land that it is now possible to direct drill into these fields with a Stanhay precision machine (probably the least suitable DD drill in the world?) with no loss in establishment or yields. The OSR in the picture above was planted like this, as are carrots, radish and fodder beet. The soil obviously has high fertility as it produces an average of 12t/ha of winter wheat, but uses only 220kg/ha of nitrogen to do it.
Weed control is made a lot easier for all these guys by growing such wide rotations. David has been practising a reduced insecticide program for a few years, and claims that this has allowed natural predators to take care of slugs to a large degree – something that used to be a big headache.
So is it the perfect system? (no!) They are very lucky to have the access and ability to grow lucrative seed contracts for such diverse species. I wish we were in such a position, but linseed, millet et al. are never going to be making £thousands per hectare. It is also very, very complicated, and I doubt that type of management requirement is for everyone. I do feel though that there is a potential for no-till, and also greater integration of sheep into our systems at home. Can it make proper money though? And do you factor in any soil improvements when making the calculation?