Spring beans: What you need to know before planting

Seed may be short, but many farmers will be putting in some beans this spring, some maybe for the first time.

Weather is due to pick up at the end of this week and beans will be high on the priority list.

Beans can be very valuable in a rotation. Research has shown that the break crop can add 0.5t/ha to a following cereal crop, as well as helping to control weeds which prove difficult in continuous cereals such as grass weeds.

The crop also provides security as many fixed-price contracts are available from buyers who want to have a native source of protein in animal feed rations.

Growers will also receive the protein payment. As approximately 10,000ha of seed is available this season that payment is set to be high.

Some of the basics of planting beans are outlined below.

Planting and seed rate

Crows can be a problem; as a result sowing depth should be increased – this can be as deep as 10cm (4in).

Beans planted in March can expect an establishment rate of 85% – the target plant population at this time of year should be 30 plants/m².

Crops which are planted in April can expect a higher establishment percentage at 95% and a target plant population of 35 plants/m².

Calculating seed rate is carried out as it is for a cereal crop. Farmers must have the target plant population; the estimated establishment percentage and the thousand seed weight (TSW).

For example, a TSW of 500 with a target plant population of 30 plants/m² and an establishment rate of 85% will give a seed rate of 176kg/ha.

Soil type

Beans grow best on soils that are not compacted due to their root system and also soils which have good water retention capabilities as they have high water demands – growers will remember 2018 when the crop performed drastically in the drought.

Fertiliser and pre-emergence

Beans do not need an application of nitrogen (N), but phosphorus (P) and potassium (K) should be applied to the seed bed and according to the soil test. Common trace element deficiencies of beans can include: manganese (Mn); magnesium (Mg); boron (B); and sulphur (S).

Pre-emergence and residual herbicides used in weed control of beans require a fine and level seedbed.