Field pea is well adapted to direct seeding or reduced tillage systems. For best results, follow the recommendations in this section on residue management, seeding management, weed control, and fertilization.
Selecting a Site
Field selection is key when planning for field pea in the rotation. In fact, planning for field pea production should begin a year prior to planting. Here are some recommendations for field selection for field peas.
- Choose fields that are thistle-free, since no herbicides are registered for complete thistle control in field pea.
- Use fall tillage or a pre-harvest glyphosate product in the crop before pea to control thistles.
- Keep good records on herbicides used in previous crops – some leave residues that will injure the pea crop. Always read the herbicide label and pay close attention to re-cropping restrictions.
- Do not seed field pea on summerfallow, on heavily manured fields, or on fields that received nitrogen the previous fall. High nitrogen levels cause excessive growth, which leads to lodging, disease, and nitrogen fixation problems.
- Avoid rocky fields. Harvest operations for field pea are usually done close to the soil surface, and rocks can damage a combine.
- Avoid poorly drained fields to reduce the incidence of seed and seedling diseases.
- A pea plant can produce two nodes in seven days under optimum conditions.
- If you are using a post-emergent product, know the correct node stage of the pea plant for safe application. Most broadleaf weed control products perform best at the two to five-node stage.
- Products such as MCPA Na salt or Tropotox Plus must be applied before the five-node stage, or severe damage can occur to the crop. The earlier these products are used, the safer they are on the crop. The exception is Pursuit, which can be used up to the six-node stage of the field pea plant.
- Node staging, not the height of the pea plant, determines time of spraying (under drought conditions, a pea plant can reach five nodes and still be only 3 in. or 7.5 cm tall).
- When counting node stages on a pea plant, the first leaves (called scale leaves) are very small and close to the stem. These are not counted.
- The point where the first true leaf joins the stem is counted as the first node; the second node occurs where the second leaf joins the stem, and so on.
- Spray early to remove weed competition.
- Pea yield potential declines every week. Spraying was delayed after pea emergence.
Proper straw and chaff management in the fall before seeding a pea crop is critical. Heavy straw conditions can create seeding problems such as hair pinning with disc openers or plugging between the shanks of an air seeder. Thick layers of chaff may also cause phytotoxicity to the next crop.
Field pea, a cool-season crop, is one of the least sensitive crops to the cooler soil temperatures associated with heavy crop residue. That makes it a great candidate for direct seeding. Keep these points in mind:
- even and wide distribution of residue with a durable straw chopper and chaff spreader is vital
- combine chaff collectors are now commercially available
- to avoid plugging shanks, stubble height should be the same or less than the shank spacing of the seeding tool
Proper rotational planning can also assist in managing heavy residue:
- avoid planting high-residue crops back-to-back
- include forages in the crop rotation
- periodically bale and remove straw
- utilize semi-dwarf (short straw) varieties in the rotation
- Direct seeding is usually defined as seeding into standing stubble. In this section, it will also be referred to as reduced tillage.
- Hair pinning refers to a condition where the seed is pushed down onto the straw layer by the opener, creating a wicking effect, where there is poor seed-to-soil contact and, as a result, patchy or poor germination of the pea crop.
- Phytotoxicity is the phenomenon of reduced growth and yields of the next year’s crop due to toxic compounds leached from the residue and/or microbial activity that produces toxic compounds during breakdown of the residue.
Field pea should be the first crop seeded in the spring, since early seeding results in higher yields and often better quality. Early seeding of field pea – ideally in late April and early May – should also result in an early harvest.
- seed placement or depth should be checked while seeding to ensure that the seeding depth targeted for is being achieved
- packing to improve seed-to-soil contact is important – but don’t overdo it, especially in heavy, wet clays (this can be especially detrimental if air temperatures rise quickly and the soil bakes and crusts)
- use seed with both high germination and vigour
- aim for a seeding rate of seven viable plants per square ft. – calculate the seeding rate for every variety seeded, as well as for every seedlot used
Less tillage means slower breakdown of crop residues, such as straw and chaff, as well as soil organic matter. Nitrogen contained in crop residue is tied up for a longer time in a direct seeding system and is less available to plants. If the field pea crop is properly inoculated, however, this should not pose a problem.
- spring banding is the most efficient method of applying fertilizer – banding fertilizer in a pea crop is better than broadcasting, since less fertilizer will be available for weed growth, especially if the fertilizer is placed close to the seed
- never sacrifice seed placement for fertilizer placement – proper seeding depth and soil-to-seed contact is critical
- in heavy clay soils, seed and fertilizer separation may be reduced due to soil lumping
- high seeding speeds may affect seed and fertilizer separation by collapsing the banding trenches
- too much seed-placed fertilizer can hurt crop emergence, cause severe crop damage and/or increased days to maturity
- studies on seed-placed phosphorus using double disc openers suggest a maximum of 30 lb./acre of P2 O5
- soil moisture conditions, row width and width of spread, soil texture and fertilizer type dictate what rate of fertilizer can be safely placed with the seed (higher moisture levels allow for more seed-placed fertilizer)
- row width and width of spread of the seeding tool determines the Seedbed Utilization (SBU) or how fertilizer is scattered in relation to the seed – wider row spacings lead to reduced seedling emergence and yield loss (the same holds true for narrow spread patterns)
- the higher the percentage of Seedbed Utilization (SBU), the more fertilizer may be placed with the seed