Resilient Fields

Best Management Practice Interactions and Considerations

Following Best Management Practices isn’t as simple as it sounds. There can be trade-offs and considerations with each cropping decision made and various environmental factors to weigh throughout an entire crop rotation cycle to protect your bottom line. Some BMPs may require societal incentives to facilitate their implementation to achieve environmental goals.

When two BMPs conflict:

Review the interactions and considerations of cropping practices below to help make the best decisions for your field.

  • Cover crops can provide environmental benefits.
To minimize conflicts between using ground cover and early planting, select plant species or species blends that are beneficial for your soil type and texture. Select cover crop species that offer slow or low vegetative growth in early spring. Reduce plant populations to a minimum. Select a cover crop mix that has some winterkill species included to minimize the amount of vegetation covering the soil prior to planting or use bio strips to minimize green cover. Including legumes or brassicas in your cover crop mix can be beneficial as they have lower carbon to nitrogen ratios. Never allow a cover crop to reach maturity. When cover crops are not in use, crop residue can also provide ground cover to protect the soil.
Early Planting and Ground Cover
  • No-till is best only if nutrient application is done properly.
No-Till and Keeping Nutrients in the Soil
No-till farming is good for the environment as well as your bottom line, but it must be coupled with good nutrient management practices to obtain the environmental benefits. Good nutrient management practices include:
  • Avoiding surface applications during high run-off risk events (early spring, late fall and winter). Consider local weather forecasts for timely application.
  • Applying nutrients onto or under a living crop cover using proper equipment. Note: if applying onto a cover crop rather than under, apply only at times of the year with low run-off risk.
  • Where practical, injecting nutrients with a coulter during planting or with a coulter or shank during a side-dress operation after crop emergence.
  • Avoiding the use of Y drop at surface application when the crop canopy is incomplete.
  • Where possible, delivering nutrients into the soil to minimize nutrient losses, especially with nitrogen and phosphorus applications.
  • Choosing cover crop blends of deep-rooted species and fibrous rooted species, which improve biodiversity and assist with nutrient cycling.
  • Lost nutrients can be costly to the financial bottom line.
Where required, subsurface drainage is an excellent tool for good soil moisture management, weather proofing and protection of your crop. Creating more infiltration opportunities is better for the environment as nutrient losses are minimized. When increasing tile density, nutrient losses by surface runoff can be reduced, but be aware, it can also carry more nutrients through the tile drain effluent. Nutrient loss through tiles and through surface runoff events can be minimized in three ways:
  1. Ensuring the soil contains living roots or dormant plant root systems.
  2. Keeping the soil surface covered by crop stubble residue or living plants.
  3. Using light/shallow tillage to break up macropores that have developed in clay soils, as these transport nutrients from the surface to the tiles.
Nutrient Loss Through Field Tiles Versus Surface Losses
  • Nitrogen loss means profit loss.
  • Nitrogen loss means GHG pollution.
Splitting N Applications and GHG Losses Nitrogen is available in several forms, and it is critical to understand the characteristics and limitations of each form to minimize loss and optimize use efficiency. Splitting nitrogen applications can greatly reduce the risk of nutrient loss through three vectors:
  1. Volatilization (gaseous loss through the air) occurring when ammonia-releasing forms of nitrogen fertilizer or manure are left on the soil surface. Risks are higher with fertilizers containing urea than other nitrogen fertilizers and increase with soil pH.
  2. Leaching of nitrogen beyond the reach of plant root systems during periods of heavy rainfall.
  3. Denitrification (the changing of nitrates and nitrites to gaseous forms of nitrogen), occurring in poorly drained and waterlogged soils.

Nitrogen application rates can be optimized by:

  • Following the 4 R guidelines.
  • Understanding the limitations of each form of nitrogen.
  • Understanding how soil moisture and temperature affect the reaction of the applied nitrogen.

Using combinations of incorporation or injection and using inhibitors can enhance the efficiency of the nitrogen applied and substantially reduce emissions of nitrous oxide, a powerful greenhouse gas. When in-season nitrogen is applied on the surface, the best results are obtained when there is the presence of a crop canopy or a cover crop. Do not apply nitrogen immediately before a forecasted heavy rainfall event. A light rainfall event can be beneficial, when applying nitrogen as an in-season split application to a growing crop. Contact your CCA to discuss appropriate options that fit your production system.

  • Cover crops can provide benefits.
  • Carefully select the right seed blend for your field situation.
  • Bio strips reduce the risk of nutrient losses and allow for warming of soils in early spring.
Cover crops are often terminated in the fall to avoid planting delay risks associated with a living crop in the field prior to planting the spring crop. Selecting species that winterkill, or seed blends containing some over-winter species and some winterkill species, allows for better control over soil moisture and temperature at planting time while maintaining a ground cover.

The keys to success are selecting the right species and application rate for the soil type, drainage conditions and heat units available. Nutrient losses can be greatly reduced, and nutrient availability can be increased by using cover crops and maintaining living ground cover for as long as possible. Bio strip or strip till cover crop management is a fairly easy way to maintain living covers with reduced planting season management and risk.

Early Planting and Ground Cover
  • Cover crops can provide benefits but must be carefully managed to minimize soil and nutrient losses.
Cover Crop Selection and P Release with Winter Onset
When a cover crop is terminated, either by tillage or frost, the plant releases phosphorus as the plant material is digested. This form of phosphorus is known as dissolved reactive phosphorus and is immediately available and therefore very harmful when it reaches our water systems. The breakdown of plant material is slow in cold temperatures; therefore, it is beneficial to use cover crop blends that contain some cold tolerant species and some species that winterkill. Preventing run-off is key to keeping this form of phosphorus in the field. Living roots will utilize phosphorus and subsequently make it available for the following crop. The presence of buffers, filter strips and grassed waterways may offer protection against surface water runoff and should be in place where appropriate. Maintaining plant residue on the soil surface with intact root systems is essential where the risk of surface run-off is high.
  • Winter spreading greatly harms the environment, wastes farm resources, and gives little benefit compared with growing season application.
  • Never spread manure on frozen ground.
  • Consider additional storage if application timing is a regular issue.
Manure should be spread on living crops as the nutrients can be immediately used as they are released. In situations where late season manure application needs to occur, and there are no living crops available, it is far better to spread the manure on a dormant crop or crop stubble than spreading onto bare ground. Nutrients are still at risk of being lost through volatilization and surface run-off when spreading manure on a dormant crop or crop stubble; therefore, consider an injection system to place manure into the soil to prevent nutrient loss. Regardless of the soil cover, never spread manure on frozen ground as the environmental risks are the highest. If application timing is a regular issue, consider additional storage solutions.

Caution: Manure should never be spread on ready-to-eat crops.

Manure Application on Dormant Crops and Efficiency
  • Tillage can provide the greatest benefits for soil health in certain situations and only with specific strategic management objectives in place.
Plowing and Soil Health

A properly operated moldboard plow, set in the root zone, is an excellent tool for the strategic treatment of compacted soils and for incorporation of heavy residue, manure, lime and fertilizer nutrients. It also aids in the management of herbicide resistant weeds, insect pests and some diseases.

Like any primary tillage tool, a moldboard plow can have both positive and negative effects on soil health. Operator mismanagement is the main reason plows have a bad reputation. A plow, when improperly set, operated with worn out parts, set too deep and bringing up subsoil, used when soils are cold and wet, used when not necessary and leaving the soil bare after plowing are all operator errors resulting in the rapid decline in soil health and structure.

As plows can leave soil susceptible to both wind and water erosion, a crop or cover crop should be established immediately following the plowing operation. This means that even with no-till, strategic tillage may be a best practice for your bottom line.

  • Using cover crops can be part of a valuable strategy for controlling weeds effectively and economically.
  • No single practice solves the weed pressures and resistance challenge.
Weed Control and ResistancePest management is a crop producer’s greatest challenge after coping with weather. Chemical rotation and strategic tillage are the common tools used to manage pests. Adding cover crops into a rotation can also be used as a management tool for weeds and other pests.

Cover crops can be used in several ways throughout the season. Post-harvest ground cover is the most common use; however, blends can be chosen to over-winter as well. Ground cover can be used as a companion crop that has a symbiotic relationship with the commercial crop. In all applications we can select plants that either shade, outcompete or employ allelopathy to inhibit certain weeds or function as a trap crop for pests harmful to yield and profit. Learning to use plants to strengthen and protect our soil and our commercial crop will result in significant reductions in chemical and tillage costs.

  • Improved soil health means improved fertility.
  • Strategic changes to farming practices can provide financial net benefits to your farming operation. Key strategies include:
    1. Reducing tillage
    2. Using cover crops optimally
    3. Increasing the number and types of crops in your rotations.

Soil is best left undisturbed and covered with living plants; however, our food and feed production system is based on annual plants in simple crop rotations with mechanical crop management from planting to harvest. In this process, soil is seldom seen as more than a growing medium and tool carrier. The use of tillage to manage crop production challenges has become habitual rather than strategic. Weather elements, the calendar, pests and the size and weight of machinery are all factors that can harm the soil. Crop production practices can result in soil compaction issues and occasionally deep surface rutting from having to manage the crop in wet soil conditions. Using simple crop rotations and leaving soil bare create a perfect storm for pests to become crop management nightmares.

Under these conditions, the only way to reset the soil for profitable crop production is to use an appropriate soil management or tillage tool to alleviate compaction, re-level soil surfaces or control a pest that has become pesticide resistant. Key strategies for improving soil health and sustainability include:

  1. Being strategic in the use of soil management equipment
  2. Following the “as little as possible, but as much as necessary” protocol regarding tillage
  3. Selecting and operating tillage implements properly
  4. Most Importantly – rotating crops and maintaining living ground cover throughout the entire year.

Weed Control and Resistance
Click on the following link to learn more about field practices that can improve soil health and regenerate your soil.
Click on the following link to learn more about tillage implements and in what field conditions they are best suited.