Planning a cropping system on a whole farm basis combines manipulating crop sequences to take advantage of biological advantages, like nutrient credits or pest suppression, with farm management criteria such as field sizes, feed requirements, financial resources and predicted commodity prices. An ideal cropping system will accomplish the following objectives:
- Meet the feed requirements of the farm, or exploit marketing opportunties
- Grow crops well-adapted to climate and soils
- Complement availability of labor, facilities and equipment resources on the farm
- Minimize pesticide use through effective IPM practices
- Efficiently use nutrients from manure and fertilizers
- Minimize environmental impacts (soil health, erosion, nutrient losses, etc.)
Realistically, most farms face numerous logistical constraints and end up with cropping plans that do not perfectly achieve all of these objectives. In these cases, farms must set priorities and design a cropping system to address critical issues firs,t while achieving acceptable results in other areas, balancing long- and short-term goals. For example, lengthy perennial forage rotations will preserve soil health, but may conflict with a dairy herd’s corn silage needs. Or a grazing operation may need to spend extra on summer labor in order to bale enough hay to permit feeding some of it during the summer to avoid overgrazing and long-term damage to pastures.
For dairy and livestock farms, the best place to start a cropping plan is to calculate feed requirements for the farm. Estimate forage and grain needs for the next three years if possible. Factor in any plans to increase or decrease herd sizes. If, in 2 years, you intend to expand the barn or buy the neighboring farm so you can put on additional animals or acres, plan ahead for the impacts on the crop rotation. Also take time to note the impacts these changes will have on your facilities and equipment needs for producing and storing more, or less, feed. A cash crop farm may start by consider opportunities in the marketplace, available grain storage facilities and existing contractual obligations.
The second step in developing a cropping plan is to estimate total forage and grain production using realistic yield estimates and accurate acreage estimates for individual fields. Include all crops or feeds in this summary – hay, haylage, dry corn, high-moisture corn, corn silage, soybean grain, etc. Avoid using overly optimistic yield or inaccurate acreage numbers. Be as accurate and realistic as possible to minimize large differences between expected and actual production. Inaccurate predictions can lead to to a discrepancies between feed requirements for the herd the actual feed inventory. Feed shortages then can require changes in rations, unplanned feed purchases or lost animal productivity. Yield estimates can be calculated in multiple ways – by counting loads and measuring average load sizes, by comparing silo capacities with the acreage required to fill them, by keeping an accurate count of bales harvested from each field, etc. Detailed field-by-field yield histories can help improve accuracy of predictions and also to identify areas where improvements in crop management are needed.
Armed with crop requirements and production capacities, next consider soil types and drainage characteristics in each field on your farm. Soil resources determine which crops can be grown most successfully. Soils should be tested on all fields every 3-4 years, or sooner if cropping system changes or new fields are included. When submitting soil samples for testing, provide accurate soil type, manure history and cropping plan information to receive the most useful interpretations. Interpretation from the lab will consider nutrient credits for previous crops as well as pH and nutrient requirements for future crops. Use all this information to plan crop sequences and field locations. Alfalfa, small grains, and soybeans grow better than corn on droughty soils. Corn grows better than alfalfa or small grains on poorly drained fields. Alfalfa and soybeans require near-neutral pH while some grasses and clovers can tolerate soil pH a bit below 6.0. Where applicable, select varieties and cultivars most suited to conditions. For corn and soybeans, this includes choosing a maturity rating that does not invite unnecessary risk of delayed fall harvest and subsequent yield loss. Planting crops that are not well adapted to specific soils and conditions leads to poor yields, increased production costs, and therefore increased acreage requirement to meet production goals.
Efficient use of nutrient credits for previous crops and manure applications and are an important component of crop rotation planning. Maximize these credits and strategies to reduce the requirement for fertilizer and chemical purchases. For example, corn following soybeans frequently produces yields 8 – 10% greater than corn after corn. Corn following a perennial forage requires significantly less N and insecticides, typically has fewer problems with weeds and produces yields 10+% greater than corn after corn. Use the crop rotation to plan adequate opportunities for manure applications before planting in the spring, after first cutting and again in the fall, after crop removal. Corn acres are not available for manure applications in July, but grass hay fields can be. Remember to factor in nutrient credits for all manure applications – which requires accurate estimates of both manure volume and nutrient content.
As many farmers adopt more conservation tillage and cover cropping practices, the crop rotation can be designed with these ideas in mind. No-till crop strategies offer some advantages for dairy producers – no-till planting methods can help to meet conservation requirements without reducing acreage of row crops; no-till planting can reduce fuel consumption and labor requirements; and no-till practices can permit more intensive rotation systems such as double-crop corn after early hay or small grain forage and double-crop small grain forage after corn silage. With careful planning, conservation tillage methods can be used successfully in Northen New York cropping systems; especially in specific situations such as planting no-till corn into fall-killed sods or soybean residue, no-till rye or alfalfa into corn silage stubble, or in some cases, no-till soybeans or annual forage into spring-killed sods.
Lastly, every farm must plan some flexibility in its cropping system to allow for unplanned variations in weather, crop yields or feed requirements. For example, in spring of 2014, alfalfa and small grain winterkill was severe on many farms and more new seedings were planted than had originally been planned. Corn was planted in fields where maintenance of perennial forages was planned. Cropping plans and animal rations were adjusted to accommodate seeding of many new hayfields and rotation of winterkilled stands into corn. Rotations can be modified to address pest problems. To avoid the need for corn rootworm insecticide applications, use crop rotation to limit the population of this pest. Shortened continuous corn sequences have been shown to reduce rootworm populations. Alfalfa snout beetle populations can escalate to the point that alfalfa in pure or mixed stands persist for only 2, maybe 3 years. In combination with entomopathogenic nematode application, shortened alfalfa rotations are necessary to reduce populations to manageable size in this situation. Build in some flexibility, and feed inventory surpluses, to protect against unplanned short-term developments.
For more information about field crop and soil management, contact your local Cornell Cooperative Extension office or contact Kitty O’Neil, CCE Northern New York directly at firstname.lastname@example.org, 315-379-9192, ext. 253, or 315-854-1218, or follow on Twitter @CCENNYCropSoil.