I have walked several fields of oil seed rape during the last few weeks. Some were our own, some belonged to other people who had invited me to assist with their seasonal vermin control. The consistent thing about what I have observed is the inconsistency of plant stands and vigour. Now I see from Andrew Blake's article in this weeks FW (p47) that this is not a Norfolk thing but is much more widespread.
On this farm, for example, we used two systems to establish our rape crops. Both could be described as min till. One involved cultivating the topsoil then conventionally drilling into it. I suspect with this system some seeds may have been drilled too deep. In any event the result (on one field) is patchy with some plants well developed and others seemingly not wanting to grow. For the record, another field treated exactly the same has a full and even plant although not as vigorous as I would like.
The second system we used involved one pass with a cultivator and air drill with the seeds being scattered behind fleet cultivations and little attempt to cover them. To be honest, it looked a bit untidy when it was first done and I was worried about it. Now, however, those fields look better than those more conventionally drilled with well established plants and few patches apart from those eaten by pigeons (that are a huge problem in this area this year).
But this week (while on vermin control) I stood on a neighbours field where the same cultivator drill had been used. There was barely a crop and those plants that were there were stunted and hardly surviving. I suspect my neighbour will have to pull it up and replant with a spring variety.
The question is - why? Rape of the same varieties, drilled at the same seed rate on consecutive days using the same equipment, into similar land, following winter wheat, should look more or less the same - shouldn't it? Can anyone provide an answer? We need to know to try to avoid the same thing happening next year.
Comments (4)
Variability in establishment of wosr is a UK problem. Of course, this season we are comparing the extreme variability with the excellent establishment achieved the year before, but in reality this season is not so different from many others.
Hutchinsons have sown 19 varieties of wosr this year using a non-inversion cultivation technique and a combination drill. Some varieties have established well, others have not. In previous trials there is a consistent message in choosing varieties to suit the establishment technique used.
Rape is very small seeded with low seed energy reserves so any set back around sowing is detrimental. Moisture is vital in the dry month of August!!! and the early part of September but equally seed to soil contact, to deliver that moisture, is equally important. Subsoiler or tine based establishment systems have worked very well this autumn but only where a reasonable tilth existed on the surface where the seed was placed. Very sticky "slotty" soils have not seen this system work too well.
Seed quality should be reviewed, was it treated pre-harvest with Glyphosate? This impacts on vigour although the a germination test will show all is well.
Straw residue levels are very important. A clear advantage of subsoiler systems is that the straw mat is cleared from the area that seed is placed. This system also allows for a very long stubble to be left at harvest, speeding harvest and reducing the amount of chopped residue on the surface. This in turn habours fewer slugs and the long stubble deters pigeons.
Slugs in 2007 have been a major headache and again it raises the issue of rotational control. Wet summer, obvious activity in crops and large numbers found in the base of crops suggests they should be treated before the new crop walks straight into the problem ...this is an area many farms need to review.
Treatment and performance of the previous crop is also worthy of note. Strob treated? Level of N input? Final yield? High N and poor yield result means there is plenty of N in the straw and breakdown is more rapid without utilising soil N ...more N for crop and better establishment, so review previous history of fields that are slow away.
These are just a few possible reasons but it is a good time to measure a few parameters for next time. Soil temp, seeding depth, straw incorporation, consolidation, variety and seed crop treatment ...you may find an answer.
Posted by richard charles neale | November 26, 2007 12:35 PM
Posted on November 26, 2007 12:35
Certainly this season, it has been much more of a challenge to consistently establish OSR compared to last where most approaches worked.
Across Masstocks many SMART Farm sites we have establishment varying from excellent to mediocre resulting from the different establishment systems we have been evaluating under different conditions. These have resulted in green area indexes going into the winter ranging from more than 1 to less than 0.5. There are some fundamental issues that have certainly been factors on the sites, and moisture management has been critical.
It is important to understand some of the fundamental factors, for instance OSR will germinate in a 10% clay soil with only 5% soil moisture but on a much stronger 50% clay soil, the soils moisture content needs to be 23%. On top of this crumb size will have a profound impact and with a clay soil at 12% moisture content, if the crumb was less than 17 mm there would be 80% emergence compared to only 5% where the crumb was more than 23 mm. Depth of drilling has also been critical with some fields establishing much better where the seed has been drilled to 2 to 3cm into moisture rather than a broadcast approach. Therefore it is very likely that some neighbouring fields, although appearing to be of similar soil type had a different enough clay content / crumb size / drilling depth to affect establishment.
We have also observed in our trials differences in moisture loss though cultivations. On one of our SMART Farm sites we cultivated across part of the plots at 9am in the morning and then drilled across the plots during the course of the day covering both fresh ground as well as across the pre-cultivated area. Where the interval was only 1 – 2 hrs, there was no difference in establishment. However where the interval between cultivation & drilling was 5+ hours, the establishment was significantly poorer where the pre-cultivation had taken place, even though the seedbed was finer. There is an old adage which suggests that the difference between a good farmer and a bad is about a week but with OSR establishment this season, it is more like a few hours!
Regarding vigour post establishment, there have been very variable amounts of rain. Looking at rainfall records from Aylesham and Wattisham, the amounts and frequency very considerably but in general, there was not much for a 5 week period from the beginning of October which has certainly affected crops early vigour.
Hopefully the above gives some pointers and highlights the importance of the messages that we have been communicating at our SMART Farm events over the past three seasons. However, we should not forget the “disastrous summer” that we have just experienced, particularly the rain. Many soils were waterlogged for a considerable period of time which probably has had a significant effect in some fields. The microbial life in the soil would have been affected by the anaerobic conditions and many broad spectrum soil & tissue analyses that have recently been carried out are showing odd levels of some nutrients. Nutrition should always be taken very seriously as any one nutrient could limit the yield potential of a crop. Many OSR crops will be undergoing floret initiation around now so it’s nutritional status is important. One Masstock agronomist recently observed that all of the crops that had been treated with our key micronutrient products looked dark green and well while those few that had not did not look as well. With current values of £275/T + oil bonuses, careful management of the crop should be very rewarding.
Posted by David Langton | November 26, 2007 3:17 PM
Posted on November 26, 2007 15:17
Many thanks to both of you. Our experience with rape is limited - having been maximising our sugar beet acreage in past years when it returned good profits. But with beet now very questionable we need to learn more about rape quickly. Your advice is much appreciated.
Posted by DAVID RICHARDSON | November 27, 2007 9:57 AM
Posted on November 27, 2007 09:57
David, if you would like to know further information regarding establishment and management of OSR we would be very happy to help you. Within Masstock we have learnt a lot about managing OSR through our trials and SMART Farm experience and we would be happy to share this with you.
If you do decide that sugar beet is not going to achieve sensible margins and you are going to grow more OSR, I would strongly urge you to consider growing HOLL oil profile OSR as you will not have double low OSR volunteers to contaminate the sample. By planting HOLL OSR you will also be locking into HOLL volunteers for the future which will keep the opportunity open. This oil profile is already in strong demand by the food industry given that it does not require hydrogenation, a process in which (bad) trans fats are produced which are becoming headline news and the demand could be 20% of UK production in a few years.
Please do contact me via david.langton@masstock.co.uk
Posted by David Langton | November 28, 2007 7:04 PM
Posted on November 28, 2007 19:04