Cover Crop Selection Tool

What is the purpose of cover crops?

The use of cover crops offers important benefits in sustainable agriculture. There are many cover crop species recognized for their various beneficial attributes, such as ability to suppress nematodes, weeds and other pests, as well as improving soil tilth and optimizing nutrient cycling.

Why is a cover crop “goal” important?

Defining your goals is crucial when selecting a cover crop as different species offer varying benefits and fulfill different functions within agricultural systems. Clear goals help tailor your cover crop choice to your specific needs, optimizing the positive impact in your fields and operation. By defining specific goals, you can select cover crops that best address your unique challenges and maximize benefits, thereby enhancing overall productivity and sustainability.

What are the different goals I can choose from?

• Soil Builder - This is a cover crop species that help builds soil structure and soil health. Certain species build soil organic matter which has many important benefits such as reduced compaction, erosion, and increased water holding capacity, microbial activity, nutrient availability, buffering capacity and more.

• Water Erosion Fighter - This is a cover crop species which reduces different types of erosion that is caused by water such as rainfall or water flowing over soil surfaces or in channels.

• Quick Growth - This is a cover crop species that grows quickly provides rapid soil coverage, reducing the amount of time that the soil is left bare and vulnerable to different types of erosion and loss of topsoil. Other benefits include weed suppression, interruption of pest cycles, nutrient scavenging, and moisture retention.

• Nitrogen Source – This is a cover crop species that provides soil nitrogen for the following crop. This includes legumes species such as vetch, peas, clovers, and lablab.

• Nitrogen Scavenger – These species quickly absorb excess nutrients from the soil, preventing leaching and making them available for the subsequent crops. These are typically used after a main cash crop.

• Winter Kill – This is a type of cover crop that natural dies off during the winter due to cold and sub-zero temperatures. These species are typically used for their ability to grow quickly, provide soil coverage, and their natural termination in the winter season. Species include oats, radishes, buckwheat, or crimson clover.

• Weed Fighter – Some fast-growing cover crop species can form a dense canopy which out-competes weeds.

• Winter Survival – This is a cover crop that survives over the winter providing soil coverage until termination timing in the spring. These can be beneficial as they maintain moisture, suppress weeds, and build soil by providing food for microbial communities which in turn assists with soil organic matter and nutrient availability for the next crop. You must consider termination or tillage when planting a cold-hardy cover crop.

• Lasting Residue – The plant material or residue of these cover crop species decompose slowly and remain on the soil surface for an extended period. This can benefit soil health and crop production by reducing erosion, improving water and soil temperature retention, aiding in weed control, and slow-releasing nutrients. It is recommended that management of residues are considered as they can impact seeding.

• Wind Erosion Fighter – This type of cover crop can assist with soil coverage and anchoring soil with roots to maintain topsoil. This can be particularly helpful in sloped fields, or soils that are susceptible to erosion such as high silt and fine sand. Grasses such as rye and buckwheat are particularly good at this.

• Quick Residue Breakdown – This is a cover crop species in which the residue breaks down quickly, which can assist in management such as flexibility in crop rotation planning, and moisture. Cover crops that decompose quickly may help soil warm up and dry out faster, allowing for timely planting. Quicker decomposition provides a food source for microbes, reduces immobilization (N lock up), and improves soil structure.

• Act as a Potential Biofumigant – These cover crop species assist in managing and suppressing pests such as nematodes or soil-born pathogens. They work as they release natural compounds with pesticidal properties such as glucosinolate, a sulfur containing compound found in brassicas (e.g., mustard, radish, and canola).

Why a Cover Crop Selection Tool?

There is a growing interest in using cover crops as part of integrated crop management strategies leading to reduced use of synthetic inputs. While a large body of information exists regarding the benefits and uses of cover crops, these must be adapted locally and properly managed to achieve their full potential, as their performance is highly dependent upon the cropping systems, soil type, and climatic conditions. To enable efficient adoption of cover crops, growers need simple means to access all the existing information and make decisions accordingly.

How did the Eastern Canada's Crop Crop Selection Tool come to be?

The web-based cover crop selection tool was originally developed through the support of Agriculture and Agrifood Canada’s Pest Management Centre, under the leadership of Dr. Laura Van Eerd (Professor at University of Guelph), and was launched in 2015 (A web-based cover crop decision tool for growers in Eastern Canada). The tool was hosted and delivered by the University of Guelph and has served the growers in the five designated eastern provinces, helping with appropriate selection of cover crop species based on their specific field