Day Twelve

My last day of visits in NZ, and no farms. Today I went to two research institutions, and one fertiliser distribution centre.IMG_2706This depot, near Rolleston, makes up custom blends of fertilisers on the fly, and they get mixed then tipped straight into either bulk trucks or fertiliser spreaders. There is pretty much everything here, from urea to DAP, elemental sulphur, MOP, TSP etc etc. These are all in bulk and get loaded with a bucket into hoppers with weigh cells attached, and from there into the mixing chamber. There is also a big stack of trace elements that can be added; the guy showing me around said they stock up to 18 ingredients in total.

Elemental sulphur is pelleted as the dust is not pleasant stuff

Elemental sulphur is pelleted as the dust is not pleasant stuff

What I really came for was to have a look at their urea dissolver. Liquid fertiliser is not big in NZ, but it does exist to some degree. This company has designed a continuous flow machine, that uses warm water to mix urea granules and water in a roughly 50:50 concentration – which results in a 19%N solution. It’s a nifty little machine as you just fill up the hopper and let it rip. The throughput is about 1,000l/hr.IMG_2709The Foundation for Arable Research (FAR) is a levy funded organisation whose aim is to perform research and extension for the arable farming community. It is they who did some of the research that Cross Slot quote in their sales material. These trials put the drill against triple-disc DD and conventional cultivations, and show CS beating the next best treatment by anywhere from 13-23%.

I have now seen some more results from FAR, covering a wide range of no-till vs min-till/plough scenarios. Out of 37 sets of results, 27 showed no significant yield difference, 6 were in favour of cultivation, and 4 no-till. Most of these experiments were using a triple-disc drill, but there were some tines (Horsch CO4 – not really a direct drill!), and some were CS. Most of the scenarios where the no-till yielded significantly less were into cereal straw, where they identified hairpinning as being the culprit. There were 12 results where the CS was compared to tillage, 8 of which showed no difference, 3 in favour of CS, and 1 tillage.

Trying to get a straight answer out of these researchers is a bit like watching Jeremy Paxman interviewing a politician. I did manage to get a sort of, maybe, admission (I hesitate to use this word, as it sounds like I was trying to extract a specific answer, but that’s how it sounded to me) that on dry land, and especially with spring drilling, there is a yield benefit from no-till. Almost every question can be answered with the familiar “it depends”, which is a bit boring really.

This is a mix of oats & marrowfat peas. The experiment is trying to show if shading the peas with the oats will reduce seed bleaching

This is a mix of oats & marrowfat peas. The experiment is trying to show if shading the peas with the oats will reduce seed bleaching (didn’t seem to be working)

Plant and Food research is a government funded body which works in a similar space to FAR. They set up a trial in 2000 called The Millennium Trial, which has come up with some interesting results (it has just finished this year). The premise was to come out of pasture, into cropping, and see what happened with different forms of cultivation. There were three farming modes,

  • Intensive: Plough, maxi-till, harrow, roll x2, drill
  • Min-till: Disc, harrow, roll x2, drill
  • No-till: drilling only

The same drill was used for all the drilling, which was normally a triple-disc Great Plains. They concentrated on spring cropping (wheat, barley and peas), and used a forage rape cover crop on half of each plot every winter, which was grazed prior to drilling in the spring. Unfortunately for us in the UK, the plots were irrigated, so removed drought stress from the equation. Here are some of the results, in brief.

  • Soil organic matter levels dropped quicker with more intensive cultivation. However, by the end of the trial they had all stabilised at the same level.
  • For the first 5 years, there was no difference in yield across the systems. But in years 6,7 & 8, the no-till massively out yielded the others, often by around 20%. I do not have the data for the years after ’07/08
  • Yields after cover crops were significantly higher than after fallow
  • The main problems for no-till were slugs

An experiment was performed this year looking at the effect of SOM levels on nitrogen availability. In other words, does having high SOM mean you need to apply less nitrogen. There is also work being done on the water holding capacity of the different plots. Preliminary, somewhat anecdotal, evidence is that the no-till plots held significantly more water than the others. All the plots were irrigated at the same time, which was unfortunately necessary due to how the irrigation equipment worked. However, I was told that if they could have been done independently, the no-till plots may well have needed around 25-30% less water. This is a very exciting result for me, and it could have huge significance for those of us who have moisture retention as a severe limiting factor. I look forward with eager anticipation to papers being published on both these topics, hopefully in time for my Nuffield report.

I know this post has been a bit short on actual detail, I may do a more in depth analysis of the research when I get sent the complete papers in the future. Or I may not.

PS I did ask about 750a vs CS comparisons. the short answer is that they don’t really care that much about specific drills. By and large they consider direct drilling to be direct drilling…

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