The Prosperity of Pulse Crops - PulsePoint
December 17, 2018
Adding a pulse to your rotation can add a $25 per acre benefit in following years’ crops
by Jane Caulfield
Researchers, growers, and agronomists agree that including a pulse as part of your crop rotation can provide nitrogen-fixation benefits to the soil, which can positively impact crops grown in rotation after pulses. While there is obvious agronomic benefits to this inclusion in
rotations, quantifying the economic benefit of pulses in rotations has always been of interest to growers, but the hardest to quantify.
“The economics of all the benefits are very hard to put an exact measure on. How do you put a value on being able to get into a field and seed it at more optimum timing, or a value on improved soil health?” says Sherrilyn Phelps, Agronomy Manager for Saskatchewan Pulse Growers (SPG). “Some researchers, such as Dr. Jeff Schoenau, are exploring the economics and have suggested a minimum of $25 per acre benefit in the year or two following a pulse crop.”
According to Phelps, the benefit provided by pulses leads to an increase in potential for higher yields and more robust harvests in the years that follow a pulse crop.
Digging Into the Economic Benefits of Pulse Crop Rotations
Crop rotations are a major contributing factor to the overall health of a crop, including breaks in disease and insect cycles.
“Inclusion of pulses in a crop rotation helps reduce disease development and severity in susceptible crops to levels below economic thresholds. This is due to the opportunity to widen the period between planting of susceptible crops on the same field, resulting in the reduction of disease pathogens,” says Dr. Patrick Mooleki, Research Scientist in Oilseed Agronomy for Agriculture and Agri-Food Canada.
Pulses are also known to have positive effects on soil quality including improved soil structure, increased soil aeration, stimulated soil biological activity, and increased organic matter.
“There are many benefits in the soils and organic matter left behind including, enhanced uptake of other nutrients such as phosphorus due to the creation of a beneficial rhizosphere from root exudates, and microbial associations and improved root growth because pulses contribute to the amelioration of soils and improvement in soil structure,” says Mooleki.
They can also help manage moisture content in soils.
“Some pulse crops are later maturing, such as faba beans, and use moisture well into the fall. In areas where excess moisture is a concern, the fields that had faba beans grown previously are often more accessible earlier in the spring, which means a grower can seed those fields sooner than other wetter fields which can be a problem in northeast Saskatchewan,” says Phelps.
Phelps adds that other pulses with shorter maturity, such as peas, can help contribute to higher moisture content because they are harvested earlier and the soil has more time to recharge. “This can be a benefit going into the next year, especially in areas of the province that tend to be drier,” she says.
The Bounty of More Nutrients
Pulses are well known for their benefit of nitrogen fixation and the positive impact it has on crops that follow in the rotation. By fixing their own nitrogen, pulse crops are not relying on soil nitrogen but importing nitrogen into the fields from the air. Some of the nitrogen that is fixed is exported in the grain, but there is still some that remains in the crop biomass left in the field.
“This biomass, which includes both above-ground and below-ground material, and root exudates, provides a source of nitrogen that becomes available to the following crop as the residue degrades,” says Phelps. “This nitrogen benefit can last up to two seasons after a pulse crop is grown.”
The exact amount of nitrogen benefit from a pulse crop varies widely and is hard to predict as many factors come into play, but nitrogen fixation can help reduce costs both up-front and after harvest.
The Long Game
Like all other crops, planting pulses still have expenses attached to it – they still have to be seeded, maintained, and harvested. And, depending on the growing year and specific environmental conditions, the crop itself may only yield a small profit. Yet, a lower cost of production of other crops because of a pulse crop in rotation, and/or increased production in the year following a pulse can prove to have a big impact.
“Since nitrogen is the number one single variable cost of production in Saskatchewan, reduction in the use of nitrogen fertilizer (during pulse year) will reduce production costs and improve the farmer’s bottom line,” says Mooleki. “Reductions in the cost of production will be seen in a lowered cost of disease and insect control due to reduced severity of infection and infestation.”
In the end, adding pulse crops to a crop rotation will prove to have benefits for years to come, which can help improve the overall health of your farm.
“The benefits to diversifying your rotation is not about returns in any one year but it is about returns over the long term,” says Phelps. “Optimizing yields to remain profitable and sustainable over the long term is what rotations are all about.”