Different farming systems use varying levels of Tillage, Technology, and Cultural Practices.

1. Ancient systems used almost no tillage, little technology, and numerous cultural practices.
2. Systems used on the plains from the time of the pioneers until perhaps the late1920's used moderate tillage, some technology, and many cultural practices.
3. Modern farming practices which have evolved in the last forty years rely on intensive tillage and substantial amounts of technology in order to reduce use of cultural practices.
4. High residue-farming systems will require renewed utilization of cultural practices to limit excessive reliance on technology

A. Weeds

1. Small seeded weeds are favored by minimum tillage and high disturbance direct seeding.
2. Low disturbance seeding techniques result in less weed pressure and more uniform weed flushes.

B. Insects

C. Diseases

1. Preventing weeds from going to seed.

1. Mowing field borders

2. Spot spraying patches.

2. Avoid introducing weeds or diseases.

1. Cleaning equipment.
2. Using clean seed.
3. Remove and feed chaff.
4. Compost manure.
5. Limit Disturbance
6. Exercise great care if grazing is to be used.
7. Treat borders and field margins.

1. Break insect and disease cycles through proper inter-crop and in crop management.

1. Control weeds and volunteer plants prior to periods when flights of cutworm and armyworm moth are expected.
2. Maintain a "no green" period especially before seeding winter wheat to break insect cycles associated with wheat streak and barley yellow dwarf mosaics and to minimize vulnerability to certain root diseases.
3. Volunteer crop and other weeds serve as hosts to carry disease and insect problems through rotational years.

D. Probiotic Vs Antibiotic or Antiseptic; Utilize biological methods rather than physical methods to lower population of harmful organisms.

1. Present systems sanitize with tillage, burning, etc. designed to kill all organisms. Hope only good ones return. Physical methods.
2. Biological methods focus on creating an environment which lowers populations through competition, predation, and planned impotence.

1. Similar to use of probiotics in livestock where introduction of beneficial or non harmful organisms lowers populations of harmful ones.
2. Establishment of crop canopy conditions which cause resting phases to become active while a non susceptible crop is being grown.(impotence)

1. green fallow vs chem. Fallow
2. continuous cropping with good rotations.
3. less inter-crop period but longer interval between the same crop type.

c) Earthworms and other soil fauna are predators.

d) Biological activity is much more rapid under full canopy conditions

1. Encourage fast uniform canopy formation.

1. Accurate seeding depth.
2. Starter fertilizers.
3. Good seed quality and seedling vigor.
4. Narrow rows.
5. Spread straw and chaff completely.
6. Move residue from the row area in some conditions.
7. Wheat with Black straw (allows faster warm-up)

3. Proper intensity reduces risk.

1. Rotations with insufficient intensity will be too wet.

1. Poor plant growth in normal to wet years
2. Loss of nutrients.
3. Trafficability problems.
4. Potential for more disease.

1. Rotations with excessive intensity will be too dry.

1. Poor plant growth in normal to dry years.
2. Difficulty in establishing adequate stands.

4. Proper intensity will depend on:

1. Weather.

1. Use two or more rotations with varying intensity if weather tends to be variable
2. Use rotations which allow adjusting intensity based on weather conditions. (i e. forage-,grain flex crops)

1. Soils: Some soils hold more water than others.

1. Soils with high water holding capacity.

1. more intensity.
2. more high water use crops.
3. longer "fallow" periods.

1. Shallow soils or coarse soils.

1. Slightly less intensity.
2. More short season crops.
3. Shorter inter-crop periods.

1. Location: Precipitation and heat interact.

1. Warm environment require more water per unit of production.
2. Native vegetation is a guide to proper intensity.

1. Irrigation: Similar Intensity at when tillage is used. (lower water costs.)

1. Irrigated systems normally have intensity limited by the heat available rather than moisture unless water supply or cost are constraints.
2. Savings occur in amount of irrigation water used.

1. runoff reduction.
2. less evaporation loss.

3) Opportunity to utilize more efficient sprinklers with lower operating pressure.

5. Native vegetation is best indicator of proper intensity.
1. Integrates precipitation, temperature, and soil factors.
1. Environments with trees will support the most intensity.
1. more water than heat. (at least for a portion of the year)
2. easily become too wet.
3. 100 percent high water use crops and/or over crops and multiple cropping.
2. Tall grass prairie mixed with trees
1. typical of the com belt and black soil zones in Canada.
2. supports substantial intensity.
3. Nearly 100 percent high water-use crops and/or cover crops and multiple cropping.
3. Tall grass prairie with few trees.
1. Too dry some years with very intense rotations (all high water use crops)
2. 75 to 100 percent high water use crops with limited use of cover crops and multiple cropping
3. Dark brown soil zone in Canada.
4. Mixed grass prairie.
1. Too dry most years for very, intense rotations.
2. 50 to 75 percent high-water use crops. No multiple cropping and few cover crops.
3. brown soil zone in Canada.
5. Short grass prairie.
1. Almost always too dry for very intense rotations.
2. 50% or less high water-use crops.
3. Longer inter crop periods required.
4. Some producers may use a small amount of fallow.
5. Rotations which allow varying intensity fit for some producers.
6. brown soil zone in Canada.
6. Short grass prairie mixed with more drought tolerant plants.
1. Almost always too dry for a high water-use crop.
2. Few if any high water-use crops in the rotation.
3. Rotations with fallow and/or flexible intensity.
6. Getting started and varying intensity
1. Look at the conventional tillage rotations in areas with similar temperatures but 2 to 4 more inches (50 to 100 mm) of rain.
1. Should be about right in terms of intensity but may not have other desirable characteristics
2. Start with rotations more intense than those used with tillage.
1. Wheat-Fallow may become Wheat-Corn-Fallow or Wheat-Sorghum-Fallow
3. Experiment with increasing intensity even more by changing one component of this new base rotation
1. Substitute a green manure crop, forage crop, or flex crop on part of the fallow acres.
1. Wheat-corn-lentil (green fallow)
2. Wheat-corn-oat/pea (for forage)
3. Wheat-corn-pea (flex)
1. Forage if dry year
2. Grain if wet year
2. Substitute a cool-season broadleaf crop for fallow on part of acreage
1. Wheat-corn-peas
2. Wheat-corn-lentils
3. Wheat-corn-flax
4. Wheat-corn-canola
3. If even more intensity appears possible, try some more intense rotations.
1. Wheat-corn-soybean
2. Wheat-corn-sunflower
3. Wheat-corn-safflower
4. Wheat-w. wheat-corn-soybean
5. Wheat-w. wheat-corn-edible bean
6. W. wheat-sunflower-corn-canola
7. Many more variations depending on climate and grower preference

1. Ability to accept risk/need or desire to maximize return.
1. Personality
2. Landlord, banker, partner, or spouses personality.
3. Debt
1. Low debt load allows the producer to accept more risk if he desires.
2. Moderate debt load may preclude taking large risks until debt is reduced.
3. High debt load may require, taking more risk in order to increase returns.
2. Other enterprises in the operation.
1. Cattle and Sheep
1. Makes forage/grain flex cropping more feasible.
2. Can utilize crops which do not initially have established local markets.
1. feed peas, corn, sorghum, forages, millet, etc.
3. Can use chaff and other aftermath to add value to the crop.
4. Planned grazing or forage sequences add diversity with little risk.
1. Grazing no-till can increase weed pressure because of disturbance. Plan rotation accordingly.
5. May limit acreage of some crops because peak times overlap.
2. Swine and poultry
1. Can utilize grains such as peas, corn, sorghum,
3. Off-farm interests.
1. Job
2. Spouse's job.
3. Hobby and leisure activities
4. Children's activities
5. Travel
1. Leisure
2. Farm or professional activities.
4. Resources
1. Labor
2. Land
3. Machinery

1. Tilled systems sometimes failed
2. Problem not that no-till does not work rather some component in the system was wrong.
3. Look to Rotation, Sanitation, and Competition for solutions.

Crops other than small grains can be successfully and profitably produced all areas of the Great Plains. Adding diversity to present rotations by growing alternative crops can have positive ecological benefit while at the same time improving the potential profitability of most operations. High residue systems benefit most from inclusion of alternative crops and in many cases use of these systems is necessary to assure adequate moisture is available to grow them. Combining high residue systems with alternative crops increases management requirements but also provides the greatest potential for increasing returns by spreading workload, optimizing efficient utilization of water; and reducing weed, disease, and insect concerns.

It is not the intent of this paper to be a comprehensive guide to rotational planning. There are, however, a couple of tools that have been helpful in our work at Dakota Lakes that make the process of evaluating rotational more straightforward in the initial phases. The first is an intensity rating. Rotational Intensity can be evaluated by assigning a value of 1 to cool-season and short-season crops and to crops used for green fallow. Examples would be all small grains, canola, pulses, millet, etc. A value of 2 is assigned to full-season crops grown during the warm part of the summer. Examples would be corn, forage sorghum, 'safflower, sunflower, edible beans, etc. Fallow receives a value of 0. Average the intensity value for each crop in the rotation. For instance a wheat-fallow rotation produces a value of 1 plus 0 divided by 2 equals 0.5. Continuous wheat, wheat-canola, etc. give values of 1.O. Wheat-Corn-Pea produces intensity of 1.33. Intensity values of no-till systems should be 0.5 to 1.5 points higher than those used with tillage depending on the tillage that was used and soil moisture holding capacity parameters.

The other tool being developed to a rotational planning is a Diversity Index. This index attempts to quantify diversity in rotations in as simple manner as possible. Like the intensity rating it designed to be used in preliminary planning only. More careful scrutiny of

promising rotations is suggested. There are two steps used in determining the Diversity Index. The first involves determining the average interval between crop types in the rotation. Crops used in the rotation are classified into one of four types (cool-season grass, cool-season broadleaf, warm-season grass, and warm-season broadleaf. Determine the number of years between each cool-season grass and the one that preceded it in the rotation. If it was the same crop (i.e. wheat both times) use the number of years as its interval. If the preceding crop was of a different crop (i.e. oats or barley) add 0.5 to the number of years. Do the same thing for the warm-season grass crops (corn, millet, forage sorghum, sorghum, etc.). Perform the same operation for the broadleaf crops disregarding the difference between warm and cool-season types. In other words use the interval between the crop of interest and the last broadleaf crop of either type. This is done since many of the broadleaf crops share diseases in common. Just as with the grass crops, remember to add the 0.5 if the preceding broadleaf was not the same crop. Average these numbers across the rotation. Fallow is treated as another crop type. Some examples are: Wheat-Fallow (1 + 1 = 2 divided by 2 years in the rotation produces and interval average of 1.0); Wheat-Corn-Pea (2+2+2=6 divided by 3 equals 2); Wheat-Barley-Canola (1.5 + 0.5 +2 = 4 divided by 3 equals 1.33); Wheat-Wheat-Canola ( 1+0+2=3 divided by 3 equals 1.0); Wheat-Canola-Millet (2+2+2=6 divided by 3 equals 2.0).

Once the interval average has been determined, the Diversity Index for a rotation is obtained by adjusting the interval average to account for some work-load spreading, weed ,and disease concerns. If both a grass a d a broadleaf crop are used in the rotation add

0.5. If both a fall and spring seeded crop are used n the rotation add 0.5. If both cool and warm-season crops are used add 0.5.

Adjust for broadleaf intervals by averaging the following scores for each broadleaf interval in the rotation: if the broadleaf to broadleaf interval is 2 years assign a 0; use 0.5 is for each broadleaf-broadleaf interval of 3 years or more; use a -0.5 for an interval of 1 year; for back to back broadleaf sequences use -1.0. Examples include rotations like wheat-canola or corn-soybean with interval averages of 1 receiving a deduction of 0.5. Wheat-corn-pea and similar rotations receive no deduction or bonus. Wheat-wheat-corn-sunflower receives a bonus of 0.5. More complex rotations like wheat-sunflower-wheat-corn-pea require that the scores from the sunflower-pea (interval = 2 years, score =0) and the pea-sunflower (interval = 1 year, score 0.5) segments be averaged to produce the -0.25 deduction for this rotation.

I

Adjust for workload spreading benefits by determining the largest proportion of the seeded acreage which shares ideal seeding time and deducting this number. Determining ideal seeding times requires local knowledge since some crops (spring wheat and canola for instance) will share seeding times in some environments and not in others. Examples would include deducting 1.0 when evaluating rotations such as spring wheat-barley, spring wheat-pea, continuous corn, and spring wheat-barley-canola since all crops need to be seeded in the same time frame in many environments. Wheat-fallow would also receive a deduction of 1.0 since all of the acres to be seeded must be drilled at one time. Rotations such as spring wheat-millet-canola in the same environment would face a deduction of

0.67. Corn-soybean, wheat-corn-fallow, wheat-soybean, wheat millet, etc. would receive a deduction of 0.5. Deductions of 0.4 would be made for a rotation like corn-soybean-corn-soybean-wheat. Wheat-millet-flax receives a deduction of 0.33 as would similar rotations. In a rotation like spring wheat-winter wheat-corn-soybean the deduction falls to 0.25.

A further deduction is made for harvest interference or where harvest of one segment interferes with seeding of another. Use of deductions for harvest and seeding-harvest conflicts (just as for seeding time conflicts) need to be made based on local knowledge. The deduction used is one-half the proportion of the acreage seeded for harvest in which conflict occurs. In most cases this value will be one-half of the value obtained for seeding conflicts. For instance, in a wheat-soybean rotation where the seeding interference deduction would be -0.5 the deduction for harvest conflict would be -0.25. In some instances, seeding will conflict but harvest will not (early maturing barley and late maturing peas share seeding times but not harvest times). If this was the case a barley-pea rotation would have a seeding deduction of 1.0 and a harvest deduction of 0.25 (one-half of 0.5). In some instances conflicts will occur between seeding one crop and harvesting another. An example would be winter wheat and millet. Millet harvest conflicts with winter wheat

seeding in some environments. Consequently, in a winter wheat-millet rotation the total deduction for harvest and seeding harvest interference is 0.5. This is derived by adding the harvest interference of 0.25 (one-half of 0.5) and the potential seeding-harvest interference of 0.25. In a winter wheat-corn-millet-fallow rotation the total deduction would be 0.33 since both the seeding and harvest-seeding interference affect only 1/3 of the seeded acreage. Rotations with high Diversity Index Values (greater than 2.5) will provide the most workload spreading and present the least disease and weed risk They will produce the most return only if they also have proper intensity, and adapted crop types are used. In some environments it may be difficult to obtain ideal levels of both diversity and intensity due to a lack of adapted crop types. In the early stages of no-till producers often have success with rotations which have proper intensity but lack of diversity. Part of this is due to the fact that the land being used has not had a history of many of the crops being used (especially the broadleaf crops) so disease and weed problems have not yet developed. Another factor is that the producer's machinery is sized for a tilled system

Lyman County Rotation Study Profitability of Dryland Rotations