Best Cover Crops for Different Applications

Cover crops may not be what you harvest and make your primary income from – but in the long run they can be an integral part of your farm and land operations and can most likely make you a financial saving in one way or another when you start to consider the benefits of sowing a cover crop.

The correct cover crop on the right land can help manage and solve a wide range of issues that can come with a fallow period. These range from minimising the risk of soil erosion, improving soil fertility and soil health, reducing the scope for weeds, pests and diseases to grow and spread and increasing biodiversity.

It is well worth considering making cover crops part of your land management calendar as the healthier your soil, the better the yield outcomes will be. And, while there will be a small initial outlay cost in buying and sowing, a good quality cover crop which takes care of the above issues stands to save you time and money down the line.

However, the type of cover crop to best meet your needs will depend upon the type of land you have, how long you want to leave the field covered before putting it back into production (sometimes this is just a matter of weeks but in some cases years), what it is you normally grow and the farming methods and machinery you use.

In this article we will look at the best cover crops for different applications, particular seasons, soil types and specific needs such as carbon sequestration, weed suppression, nitrogen fixing and soil health.

By Season

The best time to sow cover crops, like with most crops, is dependent upon the species you have chosen, the condition of your land and what you are hoping to achieve with it.

Most cover crops are sown at the back end of summer and early Autumn and missing this window can result in a poor cover. However, there are cover crops, legumes being a good example, that are best planted in late Spring and into the Summer months.

So, it might be useful to take a look at what are the best cover crops for Winter, Spring and Summer and whether they can be incorporated into an annual land management strategy.

Best Cover Crops for Winter

Brassicas are probably the most favoured crop for sowing in order to achieve Winter cover. They could be along the lines of mustards, oil or tillage radish, stubble turnip and kale.

Mid-August to mid-September is the best time of year to get these into the ground, but you could get away with the latter part of September too if you miss that window.

One of the main benefits of looking at these species in particular is that they are all relatively fast-growing in in the later Summer and early Autumn period  – but individually, they also have other qualities.

Brown and White mustards establish strong roots which are essential for keeping the plant stable, they give the soil structure and absorb water and nutrients. Mustards are also used to suppress fungi, like verticillium, rhizoctonia and worms.

Oil radish is another good choice for absorbing nutrients but also for its ability to break through compacted layers of soil, which allows for deeper rooting by the next crop. Oil radish dies off as winter runs its course and decomposes by spring, leaving soil light and easily able to absorb rain water.  

Best Cover Crops for Spring

Finding a suitable cover crop for Spring might be a little more tricky as it is a period where there is still the chance of frost and, as previous years have shown, it can also be a particularly damp time of the year.

As previously mentioned, most cover crops respond better to being sown in the period between the end of Summer and onset of Autumn, but there are others where it is better to go with them a little earlier.

Legumes fit very much into this category and in particular, Vetch and Clover are worth considering planting in order to have a Spring cover. Other benefits of Vetch are that it is good at suppressing weeds, provides nitrogen and is often used as part of a cover crop seed mixture.

With Clover there are several different varieties available, and all have their own particular benefits.

Red Clovers, for example, grow aggressively and suppress weeds while Crimson Clover is also noted for being fast-establishing and hardy. Then you have White Clover, which is very palatable for livestock and high in protein. In addition, most clover types are also particularly popular for their ability to fix nitrogen.

Best Cover Crops for Summer

Generally, most cover crops are suited to withstanding Winter and delivering benefits to the land between the end of harvest and prior to ploughing and drilling ready for the next year ahead.

But, if you do need a cover crop for summer, consider ones specifically suited to the conditions for that time of year.

Buckwheat is one such crop. It will fail in frost but is quick-growing which makes it an ideal choice for using in windows that you may have between other operations. It provides a good quick cover and is renowned for being a source of food and cover for pollinators and invertebrates, as well as deer, geese and ducks.

It is also worth noting, that if you were to let buckwheat to continue to grow for a length of time, it can produce biomass which potentially opens up the scope for wider business and environmental benefits.

Sorgham-sudangrass is another crop that responds to growing in warm conditions and where the soil is moist. It will also work as a cover crop in a mix with buckwheat. However, this would be more suited to arable farmers without livestock operations as Sorgham-sudangrass has been found to release an acid that can be toxic to animals.

By Soil Type

There is little argument to the theory that cover crops can have numerous benefits to soil in general. Neither is there much opposition to the theory that a good, healthy soil leads to a better product.

So, if you have difficult to work with soil, with clay or sand like tendencies, then the argument for a cover crop gains even more credibility as a cover crop can be saving you man hours by doing work for you.

Best Cover Crops for Clay Soil

Organic materials, ie/ crops, are a natural way to start to break down soils which are heavy and don’t drain very well. Winter wheat and winter rye are good options for clay soil as they both produce massive root systems, which break up tight and heavy material.

Best Cover Crops for Sandy Soil

At the other end of the spectrum though, is sandy soil, which is vulnerable to drought and is not as structurally sound. Hairy vetch responds well to this growing environment and grows well, releases nitrogen quickly, which can be useful for follow-on crops.

Winter Rye is another crop that can adapt to poor sand-like conditions and grass mixtures will also respond well to that kind of environment.

Cover crops in sandy soil help to improve overall soil structure but also help to retain moisture and prevent any nutrient leaching.

Cover crops for Specific Purposes

Cover crops can work in different soils, improve and break down poor soil types and do a job on your land at different times of the year. But, if you have other specific needs to across your land – suppressing weeds for example – covers are a good way to take care of this. Aside from arable benefits, cover crops are incredibly important to gamekeepers and shooting estates as well.

In this section we will look at the best cover crops for specific purposes.

Best Cover Crops to Improve Soil

It is highly unlikely you will find a cover crop that won’t bring any benefits to your soil, regardless of whether it is the best option or not. However, there are some more suitable than others and work better at different times of year.

The best Autumn cover crops for improving soil health are cereals, brassicas, legumes and other broadleaf species. Consider using mixes with different rooting depths to make sure soil is being worked at all levels and depths.

If you are looking at improving soil health with a Spring cover, consider cereals, legumes (trefoil or vetch in particular) and broadleaf crops (such as phacelia or brassicas). Again, a mix that can target different depths would be a good option.

A cover that can work the soil if you are leaving land fallow for a full year would be cereals, brassicas, legumes, oats, phacelia, mustard or radish which could even be mixed.

Best nitrogen fixing cover crops

Legumes, notably crimson clover and lupins, are the most popular choice for nitrogen fixing and they lend their qualities to the follow-on crop. Clover also helps break up heavy and compacted soil due to its root structure which allows more water to into the ground.

Vetch, also is useful for breaking up soil, is a good choice for nitrogen fixing as it has nodules on its roots containing a bacteria that converts atmospheric nitrogen into a form plants can use.

Radishes perform the same job and Daikon radishes are particularly suited to doing this. They have deep roots that help break up compacted soil layers and, as they decompose, they release nutrients, including nitrogen, into the soil.

Best cover crops for weed suppression

If you take time to understand the cover crop you are sowing and its particular traits, as well as what you are working towards on your land as a whole, then a cover crop can help eliminate weeds. A good cover crop can will out compete weeds for light and water and the chemicals it releases into the ground have a herbicide effect on seed germination of weeds and other plant species.

A number of cover crops found have these allelopathic properties and include rye, oats, barley, wheat, triticale, brassicas (oilseed rape, mustard species, radishes), buckwheat, clovers, sorghum, hairy vetch, sunflowers and fescues.

Best cover crops for carbon sequestration

In recent years there have been several pieces of research surrounding crops and their role in carbon sequestration – and potentially how that can be converted into cash.

Even if this doesn’t become an income stream, as well as reaping the benefits that cover crops give the ground, you will be playing a part in turning the tide of climate change by taking carbon dioxide out of the atmosphere.

Most of the cover crops you would normally go for will help with this such as cereals, brassicas, legumes and other broadleaf types, but there are some that have been found to be particularly effective at carbon sequestration.

Studies have suggested that cover crop mixes are more effective, for example soybean and sudangrass.

Best game cover crops

If you want to attract and rear game birds on your land, particularly pheasant and partridge, there are specific crops these birds will take to more than others.

Most of them will also bring other benefits to land management as many suppress weeds, provide cover, provide food for other small birds, are fast growing and particularly unappealing to rats, rabbits and badgers.

In this section we will look at the pros and cons of the best game cover crops.

Maize is good in a cover crop rotation, can control weeds but can also attract rats and badgers.

Sorghum is like maize in that it can suppress weeds and doesn’t have cobs, so is less likely to attract rats. However, it is not suited to cold and wet summers.

Millet is one that is also favoured by small birds, as well as game, and provides good partridge cover. If you were to go for white millet, it lasts longer than red millet.

Kale is a very popular cover crop for game interests.  It can last for two years, so is better value for money, and works well as part of a mix. In addition, it provides warm cover, is hardy and produces small seeds other birds will eat. It is sometimes hard to get established though.

Triticale, a mix of wheat and rye, is also hardy and can withstand a winter and will grow in poor conditions. It is not particularly appealing to rabbits or hares as a food source either but can attract rats, rooks and pigeons.

Quinoa is another easy to grow game cover crop and works as part of a plant mix but doesn’t offer as much cover as other crops used for game estates.

Fodder radish is a fast grower, also fine in a mix, and as it is a plant that ripens slowly it means seeds become available later on in the year when other food sources are depleted.

And finally, who doesn’t get cheered up by the sight of sunflowers? This it would seem, also is the case with partridge and pheasants. Besides the carpet of flowers that takes over the land, sunflowers produce lots of seeds that also appeal to both game birds and smaller varieties.

Summary

While fields are fallow or in rotation, a cover crop can perform many duties and even save you time, money and production costs when it comes to dealing with other challenges.

They can be a seasonal species and some will thrive better in certain weather and climate conditions but overall, covers can help to eliminate weeds, improve soil health and quality, sequester carbon, minimise problems that can come with sand or clay like soil types and provide an inviting habitat for game and other bird species.

Cover crops, while not the main focus of your business and operations in terms of products to sell or use for livestock, can be an integral part to the success of it and are well worth incorporating into your land management plans.