The Need-to-Know on Growing Pulse Crops
One of the earliest domesticated crops dating back to 10,000 BC, pulse crops are dry, edible seed that grows inside a pod, such as lentils, chickpeas and dried beans. As farmers look to diversify crop production, there has been lots of interest in growing pulse crops in the United States.
Harvested for their dry seed, pulse crops have the potential to increase cash flow on the land on which they are grown, and utilizing them in place of summer fallow practices has been known to increase a field’s microbial activity, water infiltration and nitrogen fixation.
Planting a Pulse Crop
Pulse crops are indeterminate, cool season crops, and they can grow well in arid areas where rainfall may be limited (though some farmers have seen that putting pulse crops under irrigation can lead to higher yields). Temperatures above 82 degrees F can hinder or damage growth, so early planting of pulse crops is usually encouraged. In fact, March plantings are common. If soils are 50 degrees F at planting, emergence can occur within 10 days.
When planting a pulse crop, it is important to place seed at a minimum of half an inch below the moisture line of the soil, but no deeper than three inches into the soil. Pulse seeds require three times the moisture to germinate of typical small grains, including wheat and rye.
Planting population for pulse crops depends on row spacing and is usually described in pounds per acre and seeds per pound. For example, field peas at 25-35 pounds per acre at 10,833 seeds per pound, produce best at 300,000-350,000 plants per acre, or 7 to 8 plants per square foot.
Pulse germination begins with a soil temperature of 38 degrees F, with emergence happening in 17-21 days. The growth of a pulse crop is influenced by day length and genetic variation. When days increase to a certain length, plants enter the reproductive/ flowering growth stage. The age of the plants and air temperature also influence when the reproductive stage begins. Plant growth and seed production are maximized when air temperatures range from of 50-73 degrees F.
Inoculants are Key
Inoculation is required to get an adequate population of nitrogen-fixing bacteria to supply the plants’ nitrogen needs. As with other legume crops, rhizobia bacteria grow in association with the plant roots. These bacteria fix atmospheric nitrogen gas for the plant needs. Most pulse crop growers agree that by using both liquid and dry inoculants, you can often see higher yields.
Pests to Watch Out For
The high populations mentioned earlier are an important part of a pulse crop’s weed control plan. There are currently a limited number of herbicides labeled for use in pulse crop production, so crop canopy becomes an important part of the weed control program. Also, pulse crops can be sensitive to herbicide carry-over issues. For example, small amounts of mesotrione (Callisto®) may be lethal to yellow peas for 18-24 months after application, depending on rate applied, rainfall and certain soil properties.
Diseases that are found in pulse crops can cause significant yield losses. Variety selection is key on disease management, and fungicide applications are common. The fungal and bacterial organisms that attack pulse crops complete their life cycle in the crop residue. Tillage to eliminate the crop residue is recommended, but cannot be done in the popular no-till crop systems. This means an extended crop rotation of two to five years may be required before another pulse crop can be grown.
Insects to watch for are like those of most row crops, including grasshoppers, cutworms and wireworms. A soil insecticide at planting to protect against below-ground insects can be a good idea. Knowing the field history is also a great help in determining expected insect pressures.
As with growing any crop, a reliable scouting regimen is an asset that will aid in avoiding any growing problems that surface.
Harvesting a Pulse Crop
Harvesting pulse crops can begin in late July. When plants have mature brown pods on the bottom third of the plant, with yellowing pods in middle third of plant, and green pods on top third of the plant, it is almost time to desiccate or start swathing. The crop is normally sprayed with a desiccant such as paraquat (Gramoxone®) to kill the crop, or swathed to dry approximately seven days prior to combining the plants for grain.
Always be sure to read and follow the label directions of all the pesticides used in pulse crop production.
FBN Production Contracts combine attractive crop prices with direct access to seed and chemical plans, making it easy to calculate your potential profit-per-acre for our contracts. We help our members find production contracts for identity preserved corn, soybeans, canola, chickpeas, field peas, yellow peas, pulse crops and cotton.
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