There is reportedly a a strong interest on the part of many tillage farmers in spring beans as a cropping option for 2022.
This is due to favourable contract prices (€265) and increased fertiliser costs. The protein payment is available again this year.
Beans are an excellent break crop and are profitable in their own right, but also increase profitability across the rotation.
The yield potential of beans is reduced after mid-March sowing. So growers should aim to plant beans as early as possible in March. But getting the quality of the seed bed right is critically important, according to Teagasc.
Planting spring beans
As a rule of thumb, the target should be to plant 40-45 seeds/m2, in order to establish 30-35 plants/m2.
A thousand grain weight (TGW) of 550g will need a sowing rate of 210kg/ha (13.4st/ac). Growers should take note of the TGW on the bag, as big seed requires high seed rates.
Phosphate (P) and potash (K) must be incorporated into the seedbed in P Index 1 and 2 soils to avoid additional yield loss.
However, low-P soils could lose 1.5t/ha, irrespective of fertiliser application method. There is no benefit from seedbed nitrogen (N).
It is essential that pre-emergence residual herbicides are used. Basagran is the only approved post-emergence herbicide which controls emerged broadleaved weeds and it has a very limited weed spectrum.
Pre-emergence residual products work best on fine seedbeds with some moisture after spraying.
Rolling, post-sowing, helps the activity of pre-emergence herbicides by breaking up the clods. The main pre-emergence herbicide options are: Nirvana 4.0-4.5L/ha; Nirvana 2.5L plus Defy 4.0L/ha; and, Stallion 3.0L/ha.
Cost and returns
The recently published Teagasc ‘Costs and Returns’ booklet shows that at lower yields, even with the protein payment included, beans will struggle to leave a margin.
Based on the figures published, beans need to yield in excess of 3.1t/ha to break even. However, a 5t/ha crop of beans should leave a similar margin to an 8t/ha crop of spring barley this year.
Beans like moisture-retentive soils, so soils that are prone to drying out during a normal summer are not ideal and should be avoided.
As a general rule of thumb, growers should only drill an area that they can comfortably harvest in two to three days.
Crops will be harvested in the second half of September when days are short and ground conditions are starting to deteriorate.