Spring beans make an invaluable contribution to all tillage rotations, but, like all crops, they need the best possible start.
Beans can be grown in a wide range of soil types, but they prefer a medium to heavy clay loam.
Yields of beans on light soils in dry seasons will be disappointing if drought occurs.
Beans should not be grown on peat or soils with a high organic matter content, as mineral deficiencies can occur.
Medium soils allow good root development and will usually retain enough moisture to meet the needs of the crop.
Also, medium type soils will dry out reasonably quickly in the springtime, and allow sowing to proceed in good time.
Compacted soils should be avoided, or soils where draining is impeded.
Spring beans
Root development will be stunted, and complete crop failure can result if water logging occurs.
Water logging will also stunt root growth and reduce nitrogen (N) fixation. It will also increase crop susceptibility to frost damage and disease, all of which reduces yields.
The optimum soil pH for beans is in the range: 6.5 to 7.0 If the pH reading drops below 6.0 then an application of lime is needed.
As beans are susceptible to a wide range of soil borne pests and diseases a strict rotation is necessary. A five-year break is essential between bean crops.
It is desirable that oilseed rape should not have been grown during the previous two years because of the risk of sclerotinia disease.
Providing good seedbed conditions is essential to get all crops off to a good, vigorous start. Spring beans need a medium to fine seedbed produced with the minimum of compaction.
Seeds should be sown to a depth of at least 7cm deep as soon as soil conditions are suitable from mid-February onwards.
Some winter beans are grown in Ireland. However, establishment is generally poorer on heavy clay soils, particularly in wet autumns.
Cereal drills are suitable for beans provided attention is paid to careful calibration and setting.
Row spacing of 12 to 35cm are suitable, where soil conditions allow; rolling after sowing will improve pre-emergence weed control and help prevent bird damage.
A short strawed bean variety is preferable. Growers should choose one that resists lodging and ripens early as it usually stands better, allows better air circulation within the crop.
This approach reduces disease build-up while leading to less mechanical damage during spraying operations.