Final Report for FNC95-090

Project Type: Farmer/Rancher
Funds awarded in 1995: $4,980.00
Projected End Date: 12/31/1996
Region: North Central
State: North Dakota
Project Coordinator:
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Project Information


Diversification of a cereal grain cropping system requires producers to consider alternative crops which will break disease cycles, provide adequate crop residue for moisture retention, and facilitate ease in harvest using conventional equipment. Achieving these objectives may require the interseeding of two crops to leverage the contributions of each crop to the cropping system.

The following report documents the results of interseeding field peas and yellow mustard for enhanced moisture retention and harvesting ease in a no till cropping system. Objectives of the project are stated. Materials and methods utilized to achieve the objectives of this project are outlined. Results of the project are discussed, as well as outreach plans for sharing the information with other producers.

Vern Mayer is owner/operator of a grain farm in central Hettinger County in southwest North Dakota on which small grains and oilseeds are produced. Vern has recently switched to no till production, and is constantly seeking diversification options which will allow inclusion of a legume in the crop rotation.

Producers in southwest North Dakota have traditionally utilized wheat/fallow cropping systems under conventional tillage. Environmental concerns, farm program legislation, and economics are challenging producers to diversify their cropping system to improve soil health, reduce soil erosion, and enhance crop enterprise profitability. Consequently, producers are forced to evaluate the inclusion of alternative crops in their cropping system, especially under no till conditions where crop rotation is critical for proper disease management. This is also important to conventional and reduced tillage producers who are also seeking diversification options.

Field peas are a legume crop that provide nitrogen fixation and break disease cycles in cereal grain rotations however, field peas leave little residue after harvest, thus leaving the soil vulnerable to erosion, and provide insufficient stubble for adequate snow catch and subsequent moisture retention. Interseeding the yellow mustard provides a biological trellis for the peas. Peas will climb and cling to the mustard plant, thus holding the peas erect and consequently facilitating easier harvest by allowing a higher cutting height. This results in taller stubble to improve snow catch. In addition, the mustard and peas can be easily separated because if the large disparity of seed size. The crops can then be marketed individually. However, since interseeding is a new concept in this region, it needs to be tested for agronomic as well as economic viability.

It is also necessary to test the concept of seeding mustard and peas in alternate rows. Seeding mustard and peas together has been done but there can be difficulties with stand uniformity. The uniformity of the stand is influenced by the homogeneity of the blend in the drill box and the emergence of each crop. This study will not blend the seeds, but rather meter each crop separately, thus assuring uniform seed distribution. The John Deere 750 drill has individual depth control for each opener which allows each crop to be seeded at its optimum depth. Having the peas and mustard in alternative rows, and planted at their optimum depths should allow each crop to emerge at about the same time and not experience competition until both crops are well established. Seeding in alternate rows should eliminate the tendency for one crop to overtake and crowd out the other, which can be a common problem with interseeding.

Numerous references were consulted to evaluate intercrop mixtures that would lend themselves to no till production. Corn/pinto beans, sorghum/pinto bean, rapeseed/crambe, wheat/lentil, and wheat/flax intercropping were discussed by Carr et. al. (1990). Gutek (circa 1990) discussed intercropping of field peas and oilseeds such as canola. Murray and Swenson (1983) discussed intercropping of Austrian winter peas and cereal grains. The studies presented did not address moisture retention considerations which are critical in no till cropping systems. However, the studies did provide useful guidelines in selecting an intercropping mixture that could be implemented on a practical basis in a no till farming operation. This information, coupled with local marketability of yellow mustard and Austrian winter peas, resulted in implementation of a yellow mustard and Austrian winter pea interseeding combination.

– Dwain Barondeau, Hettinger County agent, for field visits and promotion of the interseeding concept.
– Cy Hartman, agricultural worker, for equipment modification and operation
– Reed Dobitz, agricultural worker, for equipment modification and operation.
– Steve Edwardson, research director at Minn-Dak Grower Ltd. In Dickinson, ND for data collection, technical writing, photography, and software development
– The soil conservation districts of Stark and Hettinger County for promoting the interseeding concept.

– Interseed field peas and yellow mustard in alternate rows to determine if sufficient crop residue will remain after harvest to catch snow and prevent soil erosion.
– Determine if alternate row seeding of peas and mustard results in reduced crop loss of field peas, and improved crop quality by facilitating harvest of the crop combination.
– Determine if interseeding peas and mustard results in a profitable crop enterprise compared to peas planted individually.

Austrian winter peas (hereinafter referred to as field peas) and yellow mustard (hereinafter referred to as mustard) were planted in alternate rows into standing wheat stubble using a John Deere 750 no till drill. For comparison purposes, field peas and mustard were also planted individually. Prior to seeding, granular Treflan (trifluralin) was applied on the surface at a rate of 10lbs/acre of product to facilitate weed control.

Field peas were inoculated with the proper strain of rhizobium bacteria and placed in the main grain box. Yellow mustard was placed in the grass seed attachment. Alternate openings were closed in the main grain box and the grass seed attachment, thus allowing for alternate rows of peas and mustard. Each opener of the JD-750 drill was adjusted for proper seeding depth for each crop. Starter fertilizer was applied with the seed during the no till operation. Ammonia fertilizer was also applied at planting time in bands below the seed. Fertilizer applications were in accordance with soil test recommendations.

The intercrop mixture was harvested using a JD 7700 combine with a stripper header. The mono crop field pea field was harvested using a straight header, since the architecture of mono crop peas does not lend itself to utilization of a stripper header. The intercrop combination was separated at a local seed cleaning facility, and yield was determined. Because field peas tend to shatter during the harvesting process, harvest losses were estimated for the field peas in the mono crop pea stubble, as well as the pea/mustard stubble.

Moisture retention was measured on the mono crop pea stubble, as well as the pea/mustard stubble. Snow depth was measured in both stubble types in the winter of 1995-96. A Brown moisture probe was used in the spring of 1996 to estimate moisture retention in both stubble types, as well as a field that was chemical fallow in 1995. This allowed for a comparison of moisture depths between mono crop peas, pea/mustard, and chemical fallow.

Production practices were documented and entered into computer software designed to estimate the profitability of a multiple cropping system. Photographs were taken of the pea/mustard intercropping combination during the growing season.

The field pea/mustard intercrop combination is very practical in no till cropping systems. The intercrop combination resulted in 9 inches to 10 inches of remaining stubble height, compared to 2 inches to 4 inches of stubble height for field peas alone. This results in greater residue for improved snow catch and moisture retention as evidenced in table 1. Assuming a waste holding capacity of 2 inches per foot for a medium texture soil, the pea/mustard stubble had 6 inches of available moisture for the following crop, compared with 3.5 inches for the field pea stubble, and 3 inches for the chemical fallow stubble. This results in a significant moisture savings and contribution to the following crop.

Table 1. Stubble height, snow depth, and Brown moisture probe depths for chemical fallow, mono crop field peas, and pea/mustard stubble. All measurements are in inches.

Stubble Header , Height , Snow Depth, Moisture Probe
Fallow , NA , NA, NA , 18
Field Pea ,Straight Head , 3, 2 , 21
Pea/Mustard ,Stripper Head , 9, 7 , 36

*Notes in regard to table 1.
1) Values for stubble height, snow depth, and moisture probe depth represent an average of 5 measurements for each category. Measurements were taken at random in the fields.

Harvest losses of field peas were less in the field pea/mustard intercrop mix than in the mono crop pea field, as evidenced in table 2. field peas tend to lodge when mature, thus making it difficult to maneuver the combine header low enough to adequately harvest the pods and prevent shattering. Interseeding field peas with mustard resulted in a 48% reduction in harvest loss compared to mono crop field peas. This savings results in greater income per acre, and also results in less volunteer field peas in the crop planted the following year.

Table 2. Pea harvest losses in pea/mustard intercrop compared to mono crop peas.

Stubble ,Harvest Loss (seeds/sq ft), Harvest Loss (lbs/acre), Reduction % , Economic Loss ($/acre),

Field Pea, 11.5 , 217.8 , NA , $21.78
Pea/Mustard, 5.9 , 111.7 , 48.7% , $11.17

*Notes in regard to table 2:
1) There are typically 2300 seeds in one pound of field pea seed. This number was used in estimating the pounds per acre harvest loss.
2) The selling price for field peas was $10.00/cwt. This value as used in estimating economic loss per acre.
3) The harvest loss of seeds per square foot was obtained from counting harvest losses in each field in a one square foot rectangle. Harvest loss counts were taken at predetermined intervals in the field pea field (total of 84 observations), as well as the pea/mustard intercrop field (total of 36 observations). Harvest loss determination in the intercrop field was more difficult due to higher levels of crop residue.

Interseeded field peas and yellow mustard exhibited yields which were less than each crop planted in mono crop (table 3). When moisture becomes limiting during the growing season, the mustard appears to have better competition for moisture, thus resulting in reduced pea yields in the interseeded crop.

Table 3. Comparison of yields per acre for mono crop field peas, mono crop mustard, and interseeded field peas and mustard in 1996.

Crop , Yield (lbs/acre)
Field Peas , 2,114
Yellow Mustard ,1,039
– Peas , 563
– Mustard , 579

*Notes in regard to table 3:
1) Yields were determined from total production data. The interseeded pea/mustard data includes data form fields that received some drought stress. The mono crop field pea comparison field had higher rainfall, which is consequently reflected in the yield.
2) Another local farmer that also interseeded field peas and mustard obtained yields of 500 lbs/acre of yellow mustard, and 1100 lbs/acre of field peas in the interseeded situation. This field was not drought stressed, thus indicating that pea yield potential is greater in the interseeded situation when rainfall is less limiting.

Interseeded field peas and yellow mustard provided a profitable return per acre that was competitive with mono crop peas and mustard (table 4). Interseeded field peas and mustard results in slightly higher production costs than mono crop yellow mustard (due to higher field pea seed costs and seed separation costs), but slightly lower production costs than mono crop field peas.

Table 4. Comparison of crop enterprise budgets for mono crop field peas, mono crop yellow mustard, and interseeded field/peas and mustard.

Item , Mono crop Field Peas , Mono crop Yellow Mustard , Pea/Mustard Intercrop
Gross Revenue ,$211.40 , $167.21 , $135.56
Variable Costs , $63.84 , $48.44 , $58.34
ROVC , $147.46 ,$118.77, $77.22
NR/$1 , $2.50 , $2.45 , $1.32

*Notes in regard to table 4:
1) ROVC = Return Over Variable Costs. This is the return to fixed costs, family living, and unpaid operator management and labor.
2) Variable costs include the following components: seed, herbicide, fertilizer, fuel, lubrication, repairs, seed separation, and interest on operation capital.
3) Seed costs were as follows:
a. Yellow Mustard: $35.00/cwt
b. Field Peas: $16.50/cwt
4) Selling prices were $10.00/cwt for field peas, and $16.25/cwt for mustard. These prices reflect local market conditions.

The net return per dollar invested (NR/$I) is a measure of dollar use efficiency for a crop enterprise. The number is derived by dividing the return over variable costs by the variable costs (i.e. for interseeded peas and mustard, $77.22/$58.34 = $1.32). For interseeded field peas and mustard, this indicates that for every $1.00 invested in variable costs, $1.32 was returned. Although this value is lower than for mono crop field peas and mustard, harvest losses for field peas in mono culture must be considered. In addition, market volatility infield peas can result in lower returns in some years. Overall, the interseeded field pea/yellow mustard crop combination is profitable and efficient in dollar use. It must also be considered that the interseeded field pea/mustard field experienced drought stress, whereas the mono crop field did not.

Summary and Conclusions:
Interseeding field peas and yellow mustard is practical and well adapted for no till cropping systems. This study provided the following results:
1) Moisture retention is 1.7 times greater in the field pea/mustard stubble than in mono crop field pea stubble, and 2 times greater than chemical fallow. This greater level of crop residue also results in reduced soil erosion.
2) Harvesting field peas intercropped with yellow mustard results in a 48% reduction of crop loss of peas compared with harvesting mono crop peas.
3) Interseeded field peas and mustard is a profitable cropping combination
4) Production practices for interseeding field peas and mustard have been documented for use by other producers interested in this no till farming practice. These practices are itemized into a one page quick reference guide, which is presented in appendix B.

[Editor’s Note: Appendix B could not be posted online. If you would like to see Appendix B please email us at or call us at 800-529-1342. Thanks]

Other benefits of interseeding field peas and yellow mustard include: 1) nitrogen benefit from the field peas, which will be available to the following crop; 2) breaking of disease cycles in cereal grain rotations; 3) reduced soil erosion due to increased levels of residue; 4) reduced cracking of field peas during the harvesting process; and 5) faster average harvest speed [i.e. 2.4 mph for interseeded field peas and mustard compared to 2.0 mph for mono crop field peas].

This publication will be reproduced and made available to county agents, industry consultants, and producers interested in interseeding as a means for crop enterprise diversification. In addition, results from this study will be presented at grower education meetings in southwest North Dakota.

Photographs taken during the course of this study are presented in Appendix A. a brief explanation of each photograph is included to the left of the photograph.

[Editor’s Note: Appendix A could not be posted online. If you would like to see Appendix A please email us at or call us at 800-529-1342. Thanks]

The software developed for estimating the profitability of the multiple cropping combination is designed to allow producers to consider cropping combinations other than field peas and mustard. Persons interested in this software are asked to contact the project leader.


Participation Summary
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.