Crop Rotations for Increased Productivity

EB-48 (Revised), January 1998

Introduction
General Effects of Rotations
Results of Crop Rotation Experiments
Economic Considerations with Crop Rotations
Selecting a Rotation
Suggested Rotations
Bibliography

Selecting a Crop Rotation for North Dakota

When selecting a rotation, the long term viability of that rotation to reduce weed, insect and disease pressure, as well as its economic viability must be considered. A well developed plan which can be altered when necessary should always be followed. Otherwise, the desired crop sequence may be interrupted and the maximum benefits of the rotational effect will not be obtained. The following are important to consider when designing a crop rotation, regardless of location. They are: How will the previous crop affect subsequent crop production? Will the previous crop increase or decrease concerns in the following areas?

• Disease management
• Insect management
• Weed control and volunteer crop control
• Resistant weed management
• Herbicide carryover
• Residue management
• Soil moisture returns
• Seedbed preparation
• Harvest and planting schedule
• Frost risk
• Gross economic returns

Most crops with potential for rotations in North Dakota are included in Table 14. The state has been divided in to five regions (Figure 4) for purposes of describing rotations: eastern North Dakota which includes primarily the Red River Valley; northeast North Dakota; southcentral North Dakota; northwest North Dakota; and southwest North Dakota. Discussion of rotations within a particular region will refer to crops or crop groups from Table 14. Discretion must be used when making crop choices since not all crops included in Table 14 are viable options for all regions of the state.

Table 14. Crops adapted for production in North Dakota and some surrounding regions. Rotational benefits are maximized when crops from a common group do not follow each other in a rotation. A crop can be substituted for another of the same crop group in a rotation without destroying rotational benefits. The best rotational benefits are achieved when crops from groups I and II precede group III. Crops from group IV should never precede group III. Including warm and cool season crops in a rotation will spread out planting and harvest work loads.

^†Scab is generally not a problem on oats.

Figure 4. Five crop rotational regions of North Dakota based on crop growing conditions.

Suggested Rotations

Eastern region (the Red River Valley)

Unlike other regions of the state, moisture generally is not limiting, which provides growers in this region a wider array of crop choices. Corn and soybean can be produced profitably, particularly in the southern portion of the valley. The crop rotations suggested for the valley (Table 15) are not good choices for many other regions due to length of the growing season and available moisture.

Table 15. Potential rotations for the Red River Valley area of North Dakota.

† Roman numerals refer to crop group, C= cool season, W = warm season, and P = perennial.
Refer to Table 14 for crop groups and potential substitutions.

Rotation One, best suited to southeast North Dakota.

Strengths:

Two years between any one crop. Potential for scab less than with continuous small grains. Legume in rotation provides nitrogen for following crop. Two years between broadleaf reducing potential for sclerotinia. Rotation includes both cool and warm season crops.

Weakness:

Corn in same rotation with small grain, potential for survival of Fusarium (scab) fungus on corn residue.

Rotation Two, best suited to southeast North Dakota.

Strengths:

Small grain production and associated disease problems are eliminated. Soybean provides rotational benefit and increased corn production.

Weakness:

Corn and soybean are both warm season crops crowding planting and harvest. Low diversity of crops. The risk of early frost increases as you move north and short season varieties are limited; consequently this rotation is best suited to southeastern North Dakota.

Rotation Three

Strengths:

Two years out of small grains to break leaf and head diseases common to wheat and barley. Legumes provide nitrogen benefit for the small grains grown in alternate years. Includes both cool and warm season crops spreading planting and harvest time. Reduces potential for wheat midge.

Weakness:

Only one year between wheat and barley resulting in increased potential for scab, spot blotch and root rot. One year between broadleaf crops increases potential for sclerotinia, alternating flax in the 2^nd or 4^th year will reduce this problem.

Rotation Four

Strengths:

Includes two unrelated broadleaf crops. Nitrogen advantage from sugarbeet tops and from legume. Includes both warm and cool season crops.

Weakness:

Sugarbeet production not an option when sugarbeet contract acreage not available. Potential herbicide carryover to sugarbeet.

Northeast region

Rotation decisions are a complex of many factors that have short and long term consequences. A major concern in northeast North Dakota is a relatively short growing season, with some years having quite cool growing seasons. Frost damage and immaturity can be a problem for late maturing crops. Sclerotinia (white mold) in broadleaf crops and leaf and head diseases of small grains are major concerns. Surface residue becomes a concern in the wet cool years that prevent surface soil drying and good seedbed development. Obtaining crop disaster insurance is difficult for some broadleaf crops, depending on crop sequences. Table 16 contains suggested rotations for this region. Crops in similar groups usually can be substituted for suggested crops (Table 14).

Table 16. Potential rotations for Northeast North Dakota.

† Roman numerals refer to crop group, C= cool season, W = warm season, and P = perennial.
Refer to Table 14 for crop groups and potential substitutions.

Rotation One

Strengths

Achieves two year break from small grain, reducing head and leaf disease potential. Wheat does well following soybean. Herbicide rotation possible. Volunteers are controllable. Flax control in dry bean or sunflower is difficult. Residue management achievable.

Weaknesses

Sclerotinia soil levels may be maintained, although risk is low. Only one opportunity to change planting dates. Frost risk with soybean. Herbicide carryover a potential problem.

Rotation Two

Strengths

One-two year break from small grain. Small grain disease probability reduced. Residue management achievable. Volunteer crop management achievable. HRS protein and yield good following peas. Legume included in rotation.

Weaknesses

Canola, sunflower, and dry peas susceptible to sclerotinia. Only one late planted crop. Canada thistle control difficult. Canola not eligible for risk crop insurance.

Peas lost to disease not insurable with risk insurance.

Rotation Three

Strengths

Two warm season crops. High water use intensity. Three years between wheat and barley. Manageable volunteer and resistant weed control. Residue management possible. Herbicide rotation possible. Perennial weed control possible

Weaknesses

Three crops susceptible to Fusarium (scab fungus). Two crops sensitive to sclerotinia. Frost risk to corn. Solid seeded sunflower not eligible for risk crop insurance

Rotation Four

Strengths

Only one crop with high sensitivity to sclerotinia. Only one crop with high sensitivity to scab. Low surface residue production. Good weed control possible. Legume included. Fall planting helps with spring seeding workload.

Weaknesses

No warm season crop. Only one deep rooted crop. Possible winter kill of winter wheat. Harvest schedule compressed. Field pea losses due to disease not insurable with risk insurance

Rotation Five

Strengths

Three or more years of deep rooted crop. Sclerotinia and scab risk on wheat low. Potential for insect problems minimized. Multiple choices for weed control.

Weaknesses

The three years of deep rooted crops may create moisture shortage for wheat. Market for alfalfa may be limited. Requires additional equipment for haying.

Southcentral region

Growers in southcentral North Dakota have a wide array of crops to choose from when developing rotation plans. Most growers in this region have existing rotations that are relatively diverse due to a variety of factors, including a more favorable climate (e.g. longer growing season) compared to other parts of the state. Factors that limit the diversity of crop rotations include erratic moisture supplies, disease pressure, capital and labor resources, and grower production and risk management skills. Table 17 contains suggested rotations for this region and following is a discussion of advantages and disadvantages for each.

Table 17. Potential three, four and five year rotations for South-Central North Dakota.

†Roman numerals refer to crop group, C= cool season, W = warm season, and P = perennial.
Refer to Table 14 for crop groups and potential substitutions.

Three-year rotation

Strengths:

An alternative grass crop following HRS or durum wheat reduces risk of leaf and head disease. A warm-season grass allows for weed control by tillage before planting. Use of cool season crops in years one and two allow time for soil moisture regeneration. The annual grain legume reduces requirement for nitrogen fertilizer inputs. Small grain disease risk is reduced with the legume, and sclerotina should be a minimal concern for the legume. No additional equipment requirements assuming soybean is solid-seeded.

Weaknesses:

Potential for disease when wheat and barley are grown sequentially. Specialized equipment required when dry bean is grown. Potential for herbicide carryover. Legumes require improved production and marketing management skills.

Four-year rotations

A-Wheat as primary crop

Strengths:

A wheat-flax-corn-soybean rotation would maximize the diversity of crop choices (cool-season grass and broadleaf, and warm-season grass and broadleaf) and benefits. Tan spot will not be a concern in barley following wheat. Broadleaf crops following grasses will break disease and insect cycles. Wheat and especially corn or soybean in the rotation provide opportunities for weed control. A legume will provide nitrogen benefits for the subsequent small grain crops. Economic risk of a complete crop failure is reduced versus a continuous small grain or a three-year rotation.

Weaknesses:

Row crops in the rotation may require additional production equipment. Sclerotinia potential increases with a second broadleaf in the crop mix. However, flax and rowed soybean would reduce the sclerotinia risk.

* Also, consider details listed in three-year rotation discussion.

B-Potato as primary crop:

Strengths:

Three years between potato minimizes pest concerns and other potential challenges. Alternating grass and broadleaf crops disrupts pest cycles. The combination of cool and warm season crops spreads planting and harvest workloads.

Weaknesses:

Potential for herbicide residue carryover and damage to subsequent crops. Potential for sclerotinia and other diseases among broadleaf crops. Economic returns from small grain are difficult to achieve when crop production is under an irrigation system.

Five-year rotations

Strengths:

Allows optimum crop diversity and associated benefits as five different crops could be grown during the period.

Weaknesses:

Increased potential for sclerotinia in year five. Broadleaf crops highly-susceptible to sclerotinia such as sunflower, dry bean, canola, and crambe may need to be avoided in year five.

* Also, consider details listed in three- and four-year rotation discussion.

Southwest region

Water is the most limiting factor in dryland crop production in southwestern North Dakota. Accordingly, yield potentials are in proportion to the ratio of available water to potential crop water use. Matching the crop to the available water will have direct impact on the success or failure of a crop. Soybean is not generally suggested for the extreme western part of southwestern North Dakota due to the lack of moisture during flowering and early yield formation. Often precipitation in August does not provide ample moisture for soybean during this sensitive time in soybean development. In cases where severe drought is expected to result in crop failure, producers may want to consider substituting summer fallow for a crop. Table 18 contains suggested rotations for this region.

Table 18. Potential rotations for southwest North Dakota.

†Roman numerals refer to crop group, C= cool season, W = warm season, and P = perennial.
Refer to Table 14 for crop groups and potential substitutions.

Three year rotations

A - Two years of small grain

Strengths:

Third year provides break in disease cycle. Two years of short season crops increase potential for sufficient soil moisture for third full season crop. A legume in the third year provides nitrogen benefit to following crop.

Weakness:

The second year of small grain increases potential for root rot and wheat stem sawfly. The potential for diseases such as fusarium, septoria and tan spot will increase when seasonal rainfall is above normal.

B - One year of small grains

Strengths:

Third year provides break in disease cycle. Third year provides weed control opportunities not available other years. Use of corn the second year provides a greater variety of available choices for weed management.

Weakness:

Limited time available for soil water recharge after the second year and before the third year crop is planted. Late summer or early fall freezing temperatures increase the potential of second year crop losses.

Four-year rotation

Strengths:

Crops from different groups are grown every year. Depending on the crops selected in the second or fourth year, this rotation provides additional opportunities to control weeds. Most weeds, diseases and insects do not have time to increase to epidemic levels.

Weakness:

Time between the second and third year may be inadequate for soil water recharge. Safflower and sunflower use greater quantities of stored soil water and precipitation late into the growing season. Does not provide four years between crops susceptible to sclerotinia.

Five-year rotation

A - Single grain crop

Strengths:

Long break between small grains controls root diseases. Good rotation to use in saline seep recharge areas since alfalfa can use 24 inches or more water a year. Provides high quality forage for livestock feed or cash sale.

Weakness:

Alfalfa is an extensive water user. Must have use or market for alfalfa. Perennial weeds may become a problem in this rotation.

B - Multiple grain crops

Strengths:

Several opportunities to control weeds with herbicides and cultural practices. Long break between grass crops controls root disease. Provides high quality forage for livestock feed or cash sale.

Weakness:

Diseases of small grains could become a problem the second year. Stored soil water could be limiting following corn and following alfalfa.

Northwest region

Table 19 contains suggested rotations for northwestern North Dakota.

Table 19. Potential rotations for northwest North Dakota.

† Roman numerals refer to crop group, C = cool season, W = warm season, and P = perennial.
Refer to Table 14 for crop groups and potential substitutions.

Three Year

Advantages:

Legume reduces nitrogen inputs for the following wheat crop. Sclerotinia is reduced with two years out of a susceptible crop. Canola yields competitive with small grain. Year out of small grains reduces potential for scab, septoria, tan spot, wheat midge, and wheat stem sawfly.

Disadvantages:

Second year of small grain increases risk of fusarium, septoria, tan spot, root rot, wheat stem sawfly and wheat midge. With high moisture conditions and canola, a two year break between broadleaf crops could pose a higher risk of sclerotinia than a longer interval.

Four Year

Advantages:

Two of four years in broadleaf crop reduces disease potential on small grains. Three year break between broadleaf crops from group I reduces risk of sclerotinia (flax has a much lower risk of sclerotinia). Legume provides nitrogen benefit to following crop.

Disadvantages:

One year break between small grains still allows potential for root rot and other pests. Two broadleaf crops poses some increased risk of sclerotinia in canola and sunflower.

Bibliography

1. Bailey, L.D. 1982. Nitrogen fixation and legumes in crop rotation. Agdex 537/121. Ag. Canada, Brandon, Manitoba.
2. Balaruddin, M., and D.W. Meyer. 1986. Influence of including several legumes in wheat cropping systems in eastern North Dakota. North Dakota Ag. Assn. Crop Production Guide. 57:205-215.
3. Bauer, Armand and A.L. Black. 1981. Soil carbon nitrogen and bulk density comparisons in two crop land tillage systems after 25 years and in virgin grassland. Soil Sci. Soc. Am. J. 45:1166-1170.
4. Bauer, Armand, A.B. Frank and A.L. Black. 1984. Estimation of spring wheat leaf growth rates and anthesis from air temperature. Agron. J. 76:829-835.
5. Bauer and Kucera. 1978. North Dakota Exp. Sta. Bulletin 506.
6. Bauer, Armand and L. Zimmerman. 1975. Alfalfa harvested for hay as a source of available nitrogen for wheat. North Dakota Research Report 57. North Dakota State University, Fargo, North Dakota.
7. Black, A.L., P.L. Brown, A.D. Halvorson and F.H. Siddoway, 1981. Dryland cropping strategies for efficient water use to control saline seeps in the Northern Great Plains. Agriculture Water Management. 4:295-311. Elesevier Publ. Co., Amsterdam, Netherlands.
8. Bruulsema, T.W., and B.R. Christie. 1987. Nitrogen contribution to succeeding corn from alfalfa and red clover. Agron. J. 79:96-100.
9. Classen, Mark M. and David E. Kissel. 1984. Rotation with soybeans increases corn and grain sorghums yields. Kansas State University, Manhattan, Kansas.
10. Brun, L.J. and B.K. Worcester. 1975. Soil water extraction by alfalfa. Agron. J. 67:586-588.
11. Columella, L.J. 1941. On agriculture, Transl. By Harrison Boyd Ash. William Heineman Ltd. London and Harvard univ. Press, Cambridge, Massachusetts.
12. Cook, R. J., J.W. Sitton and J.T. Waldher. 1980. Evidence for Pythium as a pathogen of direct drilled wheat in the Pacific Northwest. Plant Disease. 64:102-103.
13. Crookston, Kent R., and Jim Kurle. 1986. Corn and soybean rotations six and ten year studies - Unpublished data. University of Minnesota. St. Paul, Minnesota.
14. Ellis, J.R. and T.M. McCalla. 1973. Effects of Patulin and method of application on growth stages of wheat. Applied Microbiology 25:562-566.
15. Hanson, Roger. 1986. Best sorghum follows soybeans. Crop & Soils Magazine, Aug./Sept.:23.
16. Heichel, G.H., Barnes and C.P. Vance. 1981. Proceedings, 6^th Annual Symposium, Minnesota Forage and Grassland Council, St. Paul, Minnesota.
17. Herman, W.A., W.B. McGill and J.F. Domaar. 1977. Effects of initial chemical composition on decomposition of roots of three grass species. Can. J. Soil Sci. 57:205-215.
18. Jensen, L.A. and Virgil Weiser. 1971. Crop Rotations for Profit, Extension Bulletin, No. 14. North Dakota State University, Fargo, North Dakota.
19. Maxon, A.C. 1948. Insects and diseases of the sugarbeet. Beet Sugar Development Foundation. Ft. Collins, Colorado p. 425.
20. McCalla, I.M. and F.A. Haskins. 1964. Phytotoxic substances from soil microorganisms and crop residues. Bact. Rev. 28:181-207.
21. Miller, Darrel. 1982. Alfalfa poisons new seedings. Wisconsin Agriculturist. March edition.
22. Miller, Steve. 1984. Unpublished data, crop rotations. North Dakota State University, Fargo, North Dakota.
23. Peterson, Arthur E. and Dwayne A. Rohweder. 1983. Value of cropping sequences in crop production for improving yields and controlling erosion. Depts. of Soil Science and Agronomy. University of Wisconsin, Madison, Wisconsin.
24. Robinson, R.J., Smith and J.V. Wiersma. 1979. Sunflower Monoculture and Crop Rotation. Misc. Report 166 Ag. Exp. Sta., University of Minnesota.
25. Schumaker, G.A., C.W. Robinson, W.D. Kemper, H.M. Golds and M. Amemiya. 1967. Improved soil productivity in western Colorado with fertilizers and alfalfa. Technical Bulletin 91, pp.36-37. Colorado State University, Ft. Collins, Colorado.
26. Soine, Olaf and Russ Severson. 1973. Sugarbeet rotation studies. N.W. Experiment Station. Crookston, Minnesota.
27. Tanaka, D.L., S.D. Ries, S.D. Merrill, and A.D. Halvorson. 1998. Alternative crops for rotations. In Manitoba-North Dakota Zero-Tillers Proceedings.
28. Zollinger, Richard. 1998. North Dakota Weed Guide. NDSU Circular W-253 Revised.
29. Weiser, G.C., K.F. Grafton, and D.L. Borehole. 1985. Nodulation of dry beans by commercial and indigenous strains of Rhizobium facial. Agron. J. 77:856-858.
30. Wisconsin Agri. Experiment Station, bulletin 452. 1941.

[BACK]

[Introduction] [General Effects of Rotations]
[Results of Crop Rotation Experiments]
[Economic Considerations with Crop Rotations]

EB-48 (Revised), January 1998