Back when I went to NZ for my first Nuffield trip, I wrote this in my summing up blog post:
I think I have really seen the value of plain old grass. Perhaps the Kiwis could use a refresh in their thinking as well, and start using a bit more diversity, but when it comes to soil quality and improvement, roots are king. And nothing does roots like grass.
That inspired me to plant some Italian Ryegrass as a cover crop before maize. Subsequently it transformed from a cover crop to a cash crop – it has been sold to a local dairy farmer as silage, and will be cut in a month or so. But I thought it was time to take a look at what the effect has been. And whilst I’m at it, there are a few more photos of other things that have been going on since I’ve been back from Brazil.
Last harvest was so early that this IRG got planted in mid-to-late July. It was no-tilled, which was a real benefit as we were in a very dry period at the time but it still germinated. The biggest problem with this trial has always been the potential for the IRG to become a weed in the future. It’s still a worry.
In the middle of the field I switched off the drill for 10m and left this little blank area to act as a control.
On the left is a slice taken from the bare soil, on the right from a meter away in the crop. It’s obvious how many more roots are on the right; there’s a real ripping sound when you pull it apart. Theory has it that these roots are conditioning the soil structure, and when they die, they will become Soil Organic Matter. By taking the leaves off as silage we will lose some nutrients, but I am hoping there is a net gain.
The soil surface between the rows of grass (on the right) has an incredible amount of root mass just under the old wheat straw. I’ve actually never seen anything like it, it must be soaking up a lot of nutrients. In the control patch it is just bare soil under the straw, as expected.
Time for a different type of grass. This is a field of rapeseed, which has been quite badly eaten by pigeons. But the interesting bit is between the rape plants. It’s a weed called blackgrass, which we aren’t too overcome with, but this field has a terrible patch. It’s taken three chemicals to kill it off, but eventually it looks to have worked well. Now it’s forming a great moisture retaining mulch; I’m going to call it an intentional companion crop.
When I took these photos I had only just been in the IRG field, so it made me wonder if the blackgrass had a similar effect on the soil. Luckily this patch is very well defined, so you can go from thick weeds to no weeds in a meter. On the left here is from the blackgrass patch, on the right is the clean bit. The result is very similar to the IRG field, so the companion cropping trial could be deemed a success…
More grass: Black Oats (and vetch, which is very hard to find). This was always going to be marginal, as they were scheduled to be planted in late October/early November after sugar beet. Unfortunately it went in around a month after that, and never really got going. The idea was to suppress some blackgrass and to improve soil structure after it had been absolutely hammered by the sugar beet harvesting. We killed it off last week (same day these photos were taken) ready for planting spring barley. Was it a waste of money? I suspect so.
We’ve had this drill for 13 years or so, this is the first time it has been pulled by a wheeled tractor. Although this one is still a lot of machine, it’s lighter, more comfortable, more versatile and cheaper to run than our Challenger. It may be the end of tracked vehicles on this farm.
I had to stop drilling peas and get out to take a photo when I saw this. It was wheat last year, then a cover crop which was grazed before Christmas. The greeny-yellow strip is where I missed a bit when planting the cover crop, so it has been bare since the summer. As you can clearly see, it is stuffed full of blackgrass, compared to next door which has almost none. The big question will be, is this a good thing or not? One school of thought is that it’s better to have the weeds germinate so they can be killed prior to planting the spring crop. I’ll have to keep an eye on it over the growing season to see which bit, if any, has the higher weed population
That’s it for grasses. We are running a sugar beet establishment trial this year, helped out by BBRO. Most of the field is ploughed, but some has been strip-tilled (with a StripCat, excellent machine) and some no-tilled. All was drilled with a loaned Vaderstad Tempo, which had a few teething problems. It did an OK job on the no-till, the main problem being that the closing wheels were designed for working in loose cultivated soil, and so did not always cover the seed properly. This would be simple to fix with some spiked wheels.
This is the junction of no-till vs plough. There should be no doubt as to which one will retain moisture better in the summer, and this is light land that dries out easily. But that is only one factor, so who knows what the final result will be?