Perennial grasses are potentially one of the most useful crops to grow… if you’re a cattle farmer. But what if they had some real use for farming in general? We explore how using perennial grasses as part of a cover crop rotation can aid your farm, leading to improved soil conditions and yield improvement. Bear in mind that with such a huge variety of different grasses to decide between, from oats to winter rye to Sudan grass, there’s bound to be a suitable grass for your climate, which you can find with a little research.
Advantages of Sod Rotation
- Planting any cover crop is better than leaving fields barren in terms of preventing soil erosion, but grass cover crops in particular are extra effective at this due to the extensive root systems they tend to have. Keeping your soil locked in place while years of grass crops add more nutrients to the soil will have your fields in good shape ready for improved yields next season.
- Using grass as a cover crop opens up your fields to multiple uses. You can graze cattle on your fields while you’re in a cover crop year in your rotation, giving your usual pastures a break and fertilising your grass field naturally with the manure from cattle. Varieties of ryegrass and white clover in particular are popular choices for pastures: check which grasses are best suited to your climate and are cattle grazing friendly before investing.
- Choosing a grass to cover your fields, even if it’s not a particularly useful grass variety, will aid weed suppression without the need for herbicides, ensuring your fields are unlikely to be consumed by toxic or difficult to remove weeds. Furthermore, leaving fields to grow into meadows while the grass works its magic in combatting soil erosion and improving soil nutrients also does wonders for the wildlife and local ecosystem.
- Last, but certainly not least, using perennial grass cover crops is proven to boost crop growth and improve yields for years to come. David Wright, an agronomy professor from the University of Florida, has “found that sod-based rotated crops use 70 percent less water, and … there has been an increase in peanut yields by 25 to 40 percent.” Depending on the types of crops you grow, you could see similar improvements on your farm.
Disadvantages of Sod Rotation
- While your fields are host to your chosen grass cover crop, they tend to go to waste unless you’ve got cattle to graze, or some other use for your field in the meantime. In previous articles we’ve come up with various interesting ideas on how to make use of empty space, from hosting music festivals to camping grounds, however you really can’t dedicate your grass growing areas to these heavy use activities without damaging the soil. Your only real options are grazing or choosing a grass that you can sell at the end of the season.
- Many perennial grass crops have low amounts of nitrogen in them by the time they mature. If you can’t fertilise your fields while the grass grows with manure from grazing cattle, the helpful grass crops can actually do harm by reducing the levels of nitrogen in the soil by the end of the season. To combat this and ensure that your soil is nitrogen rich for your crops next season, try removing grass before it matures using herbicides.
- Using cover crops to promote yield improvement as part of your farm management plans is a long term game with few short term benefits. Depending on your rotation schedule, you might not be turning a profit from your grass growing fields immediately, while the benefits in yield improvement definitely won’t be seen until potentially years of soil improvement through sod cover crops.
This example rotation from Wright recommends this as a good choice for farmers in the area, where they have been researching sod based rotation for over a decade.
Year 1 and 2: Bahia grass (suitable for cattle grazing and therefore can also be sold as bundles of hay)
Year 3: Peanut (nitrogen fixing after 2 years of grass crops potentially reducing soil nitrogen levels)
Year 4: Cotton (particularly susceptible to soil erosion and wind-blown soil – problems the grass cover crop should have countered)
Year 5: return to grass (begin the cycle again, allow the soil quality to improve and cattle to graze)
This all just goes to show how beneficial grass cover crop rotation could be, if you take it seriously. That means properly planning out the next few years and having a good agronomical understanding of the crops you’re growing as well as the geography and climate of your farm. What works for Florida farmers needs to be adapted and changed by picking out suitable grasses for your own cover crop rotation. Your next step? Find the perennials that work for you and start working towards better farm management and increased.