Day 60 – Viva la resistencia

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Last day in Rosario, and here’s a tip if you ever visit. Don’t go to a sushi restaurant.

Again I was hosted by AAPRESID, and it occurs to me I haven’t actually mentioned them before now. AAPRESID is the Argentinian farmers no-till association, and it’s based in Rosario. They organise farmer groups, like CREA, but also run trials, and once a year organise a huge conference. And let’s not forget all the foreigners they kindly show around the country too.

Red Angus cows & bulls

Red Angus cows & bulls

Today’s visit was to a lady farmer who is using cattle to improve her soils. More specifically, there are some low-lying areas which have suffered from water erosion in the past, and she makes more money there with the animals than with crops. In fact, the beef price is so good here compared to grain that the animals are the most profitable side of the business. Given that the pastures are improving the soils, the brave move would be to put some of the crop fields down to grass for a few years. But that’s easy for me to say from here…

Bird's foot trefoil on left, mixed species ley on right

Bird’s foot trefoil on left, mixed species ley on right

The pastures hon this farm are far more complex than others I’ve seen in the country. Depending on the specific conditions in each field they use tall fescue, brome, lucerne/alfalfa, white clover, red clover and trefoil. The farm’s agronomist, Daniel Canova, is a big advocate for having as many different root types in a rotation as possible; he is sure that this helps to prevent compaction and keep the soils productive. These fields tick that box.

Superficially impressive root nodules on a Soya plant, although most of them were not functional

Superficially impressive root nodules on a Soya plant, although most of them weren’t functional

One of the problems in the GMO using world is the spread of glyphosate resistant weeds. AAPRESID have a team working on this, and they anticipate the number of resistant species will increase quickly in the coming years. We don’t use GMOs in the EU at the moment, but I’m sure that will change in the medium term. When the day comes, it’s of critical importance that we learn the lessons from all of these countries (north & south America, Australia etc) to keep our chemicals working. The temptation will be strong to be lazy: “it won’t happen to me”.

The biggest problems come from using the same crop every year, and then using multiple doses of the same chemical. Here that plant is soya, in the US it’s also maize. So step one is to keep on rotating crops, both for their differing natural weed suppression, but also because it will allow the use of different types of chemicals each year. But what if you have a field, like the pastures here, with have so many different plant types that chemical control is not possible?

Sorghum growing as part of a resistant-weed management technique

Forage sorghum growing as part of a resistant-weed management technique

These pastures are normally kept for four years, by which time they are getting a bit tired (I can’t help but feel some more involved grazing management would help here). At this point field is sprayed off with glyphosate. If there are enough resistant weeds left over, they will then drill oats. The reason for this is simple – their roots have strong allelopathic effects. This means that they exude chemicals which stop other plants from growing. [We currently have a field of oats at home which will hopefully reduce the amount of black grass in the following barley crop.]

Once the oats have grown enough, they are grazed, and then forage sorghum is planted on top of them. Again this will be grazed, but not when the plants are small as it can cause nitrate poisoning which is undesirable in cattle (their mouths turn blue and they die). There might be time for a couple of grazings before the new pasture is sown, but by now the weed burden should be reduced significantly. I think one of the reasons this works so well here is that all the weed seeds are left on the surface because of no-till, and in this climate they will be decomposed very quickly – even after maize the residue is totally gone within six months.

So there we have it, some ideas for farming in Europe in the ’20s. I’ll end with this photo of a typical Argentine motorcycle rider, taken on the motorway outside Buenos Aires.