Tillage: Sowing conditions rather than date is the critical factor for beans
Published 16/03/2016 | 02:30
Last year many had taken advantage of a good spell in February to get beans sown into excellent conditions. This year of course it's a bit different. Beans performed well last year and there will be plenty of interest in the crop again this year.
Work carried out in Teagasc Oakpark, albeit results from one season at one site, will give a level of comfort to those of us accustomed to pushing sowing the crop in January or February.
These results suggest that sowing date is not as critical a factor as we thought. Sowing conditions are however critical. The seed will not take kindly to being flung into a compacted mess, and will respond with poor establishment and consequently, poor yield. Another achilles heel of the crop, weed control, will also suffer from poor seedbeds.
The only viable weed control strategy for beans is the use of pre-emergent residual herbicides. Beans do not form a dense crop canopy to smother out late season weeds, so the herbicide is required to work for the full life cycle of the crop, or up to 26 weeks.
In order to be effective therefore, everything has to go right for the herbicide to work season long.
Applying residual herbicides onto a cloddy seedbed is not the way to get the best out of the herbicide and the worst case scenario is a new flush of weeds starting to swamp the flowering crop late in the season. 'Well sown is half grown', is a mantra repeated ad-nauseum, but with good reason.
Given the long winter we have endured, there are plenty of organic manures like slurry, farmyard manure and even soiled water looking for a new home and given the outlook for crops this year, getting the P and K requirement from organic manures makes sense.
However, with the high proportion of land that is sown into winter cereals this year, in some areas there is a shortage of land available to take manures this spring and land destined for beans may well be a good opportunity to utilise organic manures.
The work carried out at Oakpark suggested that beans do not respond to external nitrogen sources, so low nitrogen organic manures such as farmyard manure or spent mushroom compost might be best.
However, any organic manures will have benefit to the soil and at any decent amount should meet most or all of the P or K requirements of the crop. As a fertility building exercise, the double whammy of beans and organic manure will bear significant long term benefit to a parcel.
Organic manures, though, are cumbersome and weighty and could cause compaction difficulties if soil conditions are not suitable to carry the weight of application machinery.
So timing is everything and there is a wafer thin opportunity for applying organic manures onto a soil dry enough to bear traffic before getting the crop into the ground in good time. This holds for any spring crop.
The increasing bean acreage last year has resulted in a significant increase in the tonnage of beans available for use in compound feed manufacture. There has always been a chicken and egg problem with beans in feed manufacture.
Compounders couldn't justify the change in formulation necessary in their mainstream lines such as poultry or pig meal to include beans when there were so little beans available, which in turn reduced demand for the crop.
The Irish and EU taxpayer has responded to this conundrum by stimulating availability through subsidisation of the production area and it's now over to the compound feed manufactures to utilise this crop to best effect.
There are difficulties associated with utilising the crop; the amino acid make-up, the difficulty drying and milling such a large grain and creating a balanced formulation from a new ingredient, all issues that can be overcome.
We utilise somewhere around 4 million tonnes of compound feed per annum, but import more than 2.5 million tonnes to make up this amount.
Everyone wants to sell their product as Irish and proudly displays the Irish flag whenever possible.
We now have a situation where a fully native compound feed can be made available on a fairly large scale and this will test the mettle of those who are so brash proclaiming the Irish heritage of their produce. If selling Irish produce is so important, surely it follows that sourcing native inputs is equally important?
Dr Richard Hackett is an agronomist based in north Co Dublin and is a member of the ITCA and ACA.