Cover Crop Selector

Select the best cover crop species based on your management goals — nitrogen fixation, erosion control, compaction relief, or weed suppression.

About the Cover Crop Selector

Cover crops protect and improve soil between cash crop seasons. Different species excel at different goals: legumes fix nitrogen, grasses produce biomass for erosion control, brassicas break compaction with deep taproots, and vigorous species suppress weeds through fast canopy closure.

This selector tool helps you rank cover crop species based on your primary management objective. Enter your goal, and the tool recommends species suited to that purpose, along with approximate seeding rates and expected benefits. Many farms plant multi-species mixes to address multiple goals simultaneously.

Combine this tool with your frost date and crop rotation planners to integrate cover crops into your operation seamlessly. Whether you are a beginner or experienced professional, this free online tool provides instant, reliable results without manual computation. By automating the calculation, you save time and reduce the risk of costly errors in your planning and decision-making process. This tool handles all the complex arithmetic so you can focus on interpreting results and making informed decisions based on accurate data.

Why Use This Cover Crop Selector?

With dozens of cover crop species available, choosing the right one can be overwhelming. This selector narrows the options based on what you want to achieve — whether it's reducing nitrogen fertilizer purchases, preventing erosion, building soil organic matter, or outcompeting weeds. Having a precise figure at your fingertips empowers better planning and more confident decisions.

How to Use This Calculator

  1. Select your primary management goal from the dropdown.
  2. Review the ranked list of recommended cover crop species.
  3. Note the approximate seeding rate for each species.
  4. Consider a multi-species mix for multiple benefits.
  5. Check species winterhardiness for your zone before planting.
  6. Plan termination timing to avoid interference with the following cash crop.

Formula

Species Ranking = Goal weight × Species trait score for each goal category Overall Score = Sum of (goal weight × trait score) for top-ranked species

Example Calculation

Result: Top picks: Crimson Clover, Hairy Vetch, Austrian Winter Peas

For nitrogen fixation, legume species rank highest. Crimson clover produces 60-150 lbs N/ac, hairy vetch 60-120 lbs N/ac, and Austrian winter peas 40-80 lbs N/ac when terminated at flowering.

Tips & Best Practices

Cover Crop Species Categories

Grasses (cereal rye, oats, triticale) produce high biomass, scavenge excess nitrogen, and suppress weeds. Legumes (crimson clover, hairy vetch, peas) fix nitrogen and provide N credit to the following crop. Brassicas (radishes, turnips, rapeseed) break compaction with deep taproots and cycle nutrients from depth.

Multi-Species Mixes

Mixes capture synergies between species. A common three-way mix is cereal rye + crimson clover + radish, which combines weed suppression, nitrogen fixation, and compaction relief. Mixes also improve biodiversity, support pollinators, and provide more consistent performance across variable field conditions.

Economics of Cover Crops

Seed cost ranges from $10-$40/ac. Establishment cost adds $5-$15/ac for drilling or aerial application. Benefits include reduced fertilizer cost (N credits), improved yields, reduced erosion, and potential NRCS cost-share payments. The net economic impact is typically positive within 2-3 years of adoption.

Frequently Asked Questions

What is the best general-purpose cover crop?

Cereal rye is the most versatile and widely adapted cover crop. It establishes quickly in fall, survives winter in most zones, produces excellent biomass for weed suppression, and is easy to terminate in spring.

How much nitrogen do cover crops fix?

Legume cover crops can fix 40-200 lbs N/ac depending on species, growth duration, and termination timing. Crimson clover and hairy vetch are among the highest N producers when allowed to reach flowering before termination.

When should I terminate cover crops?

Terminate at least 10-14 days before planting the cash crop. Use herbicide burndown, roller crimping, or tillage depending on your system. Later termination produces more biomass but increases the risk of cash crop interference.

Do cover crops reduce yields of the following crop?

When managed properly (timely termination, adequate planting window), cover crops typically maintain or increase yields through improved soil health, moisture retention, and nitrogen credits. Poorly managed cover crops can tie up moisture or N.

Can I graze cover crops?

Yes. Many farms graze cover crops, especially multi-species mixes with brassicas and legumes. Managed grazing provides additional revenue while still delivering soil health benefits from the root growth and residual biomass.

What if I have a short window between harvest and freeze?

Choose fast-establishing species like cereal rye, oats, or radishes that can germinate and grow quickly in cool temperatures. Radishes winterkill and decompose, reducing spring management needs.

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