Spring peas are legumes. They absorb nitrogen from the air through nodules and release it again after the seeds are harvested. They are excellent as first crops in a crop rotation. They need to be sown in deep, healthy, and relatively dry soils. They do not flourish in stony soils. They are not adapted for associations with certain intercrops, which should be avoided. Advice on selecting cover crops to sow before spring peas.
Avoid planting legume-based intercrops
Agronomically speaking, the choice of cover crop should include alternating crop families. The aim is to avoid providing favourable environments for certain pests and weeds. Spring peas are highly vulnerable to aphanomyces, a fungus that leads to considerable loss in yield. To combat this disease, a fairly long rotation of at least 6 years is recommended.
Legumes, such as lentils or field peas, should not be used as a cover crop prior to spring peas. Some legume varieties are resistant to the fungus, however: common vetch, red and white clover. Mixed cover crops can also be used. As yet, there are no conclusive scientific results on the risks concerning alfalfa or grass pea though. But many different cover crops can be sown before spring pea. Take care, however, as crucifers and certain mixes are sensitive to sclerotinia, which can also affect peas.
Agronomic logic: opt for a cropping system with diversified botanical families.
Choose cover crops that are beneficial to protein pea crops
Cover crops planted before spring peas should cover the soil and fix nitrates. It is not necessary for them to release nitrogen into the soil because spring peas are capable of absorbing nitrogen from the air. There are many suitable cover crops:
- Crucifers: rape, mustard, radish.
- Grain crops: rye, oats, Italian ryegrass.
- Hydrophyllaceae, such as phacelia.
Cover crop destruction should be started on November 15th, if regulations allow. Otherwise, follow the regulations in your area.
Peas in the crop rotation: what other crops can be sown?
Peas are often a very good crop to sow before wheat and rape in a rotation. They release nitrogen into the soil and have a beneficial effect on soil structure due to their taproot system. Early harvest in summer prevents compaction due to poor bearing capacity during wet periods. The different seeding and harvesting dates make it an easy crop to integrate into a farm’s growing schedule.
Peas are beneficial as part of the overall rotation. They reduce the need for nitrogen fertilisers and weedkillers while increasing the yield of the crops that follow.