Grain talk
Can anyone explain what happened crops in 2012? The simple answer is no! Last week at the ploughing, many of you reported common experiences from your harvest that are worth recording because, individually, you may feel that you are unique.
These related to yield levels on different land, experiences with rotation, grains not germinating on stubbles, etc.
Unexpected yield
responses
One of the most obvious findings flies in the face of traditional good farming practice - well managed fields in a rotation yielded less than poorer fields.
This is perhaps the first time that growers have seen such an occurrence. It was most obvious in winter wheat where very high yield potential first wheat slots had lower yield and quality than poorer continuous wheat slots. The common comment was that the best crops in June finished worst and vice versa.
The high potential yield crops disappointed most and generally had the lowest yield also.
It would seem that lower potential yield crops on lighter or sandy land and second wheat slots etc had some combination of lower head count, smaller ear size or fewer grains per spikelet and that this smaller number of grains ended up being better filled and provided both higher yield and better quality at harvest.
Fewer grain sites appeared to be a bonus this year. Prior to harvest, I had commented that the loss of a proportion of grain sites to ear blight could prove to be a blessing in disguise, as fewer grains could be filled better.
This was most obvious in some crops of spring barley where a combination of low tillering and grain loss resulted in a low grain number per square metre being well filled and producing a specific weight of 68KPH at harvest despite yields in the region of 1.4-1.6 t/ac.
And in the same way what looked like five tonne plus crops of winter wheat in June ended up at 2.6 t/ac with a specific weight of 63-65KPH.
Why did this happen? My simple understanding of plant science would suggest that good and poor crops could end up with the same yield if a limiting factor came into play.
In this scenario, the good crop with the higher grain count would show lower quality. But the good crop slots - the first wheat after potatoes or oilseed rape or oats - produced lower yield generally, suggesting less net photosynthesis to fill the bigger grain number. So is there something else going on?
Wet, wet, wet
For my money, I believe that the biggest overall impact on crop performance this year came from soil wetness.
Farms that tended to be hit with fewer showers seemed to have higher yields and in a number of instances some land actually yielded higher in 2012 than in 2011.
Rainfall amount, and its impact on soil type, seemed critical in 2012. Fields that escaped a number of critical heavy showers during June and July appeared to escape the worst of the impact and sandy free-draining land that would normally be limited by soil texture appeared to deliver its normal yield potential in 2012.
But I am left wondering why the good fields could not perform better? Is it possible that crops with big canopies also have proportionally bigger root mass and was this an obstacle in 2012?
Plant roots have to be able to breathe also and this is not possible in a water-logged soil.
Or could it be that the sustained water logging resulted in the excretion or build-up of substances that were antagonistic to plant growth? And did this effect occur to a greater degree in higher yield potential crops with bigger canopies?
Barley less affected
Another point that was clearly reiterated in 2012 harvest is the relative suitability of spring barley to our climate.
Winter barley had a relatively good year but the six-row types suffered more on yield in a mediocre grain filling season. The result was poorer grain fill in many six-row crops, with associated yield and quality reduction.
Late green tillers in spring barley were a problem for some growers. This is most likely associated with late nitrogen availability, either through late N application or the late availability of N originating from soil mineralisation.
Normally, late tillers are associated with crops that are on the thin side where light can get down to the base of the stems and encourage late tillers to develop.
But this year late tillers developed even in dense crops but this could be a consequence of growth regulator application?
Quality impact
and high proteins
With specific weights tending on the low side, it is likely that poor grain fill may result in higher grain proteins and this should add indirectly to the value of grain, given the high cost of soya currently.
In our climate, the protein content of all grains tends to be diluted by the normally high starch content associated with our high yields but this was not the case this year.
This was seen in the higher rejection of malting barley due to excessive protein late in the season as yields faded somewhat.
Ungerminated seeds
in stubbles
Many growers commented on the number of seeds, good and bad, visible on stubbles that have not germinated post harvest.
Did anyone wonder about the relatively low level of visible sprouting in crops during harvest compared with other years?
Years that have wet weather at the end of grain fill and into the maturing stage tend to make the plant produce a higher level of dormancy to protect its seeds from premature germination.
So dormancy was always going to be an issue post harvest and it is slowing the availability of certified seed, as well as preventing seeds on the stubble surface from germinating.
But the vast majority of these can germinate and therefore they leave the risk of a weed problem with volunteer plants appearing in the following crop, eg oats in barley or wheat or wheat seeds in barley.
Any form of simple stubble cultivation will help them to break dormancy and germinate.
Source: farmersjournal.ie