Cover Crops

Cover crops fulfill several of the principles of soil health and therefore have multiple benefits for vineyards. First and foremost, cover crops protect the soil from erosion and thus they are needed to avoid the damage from intense rain events, especially in vineyards on slopes. Second, cover crops add organic matter to the soil through above and below ground (root) biomass. Third, cover crops increase crop diversity within the vineyard and attract pollinators and other beneficial insects, thus increasing overall vineyard biodiversity. Also, cover crops can help suppress or shift weed establishment in vineyards (Baumgartner et al. 2008). Lastly, cover crop presence between fall and spring provides the vineyard system with living roots during vine dormancy, thus maintaining year-round living roots within the vineyard (Steenwerth and Belina, 2008).

If You're Considering Cover Crops

One of the first questions to ask when thinking about cover crop management is, “What are my goals for this farming practice?” There are many purposes for seeding a cover crop. This question is important in determining which type of cover crop seed to use. The four general functions of a cover crop are to stop soil erosion, assist in pest management, provide nutrients to the soil, and compete for water in high vigor situations. 

1. A low growing grass that has good drought tolerance will create a permanent cover crop to prevent soil erosion. 
2. Certain types of brassica can help with nematode populations and improve soil tilth. 
3. Legumes are great for nitrogen fixation, but they can be difficult to manage and potentially lead to unintended pest pressures.
4. Aggressive grasses are a smart choice for spring moisture competition. There is also the option to cultivate the soil in the drought years in case of lack of rainfall.

How to Seed a Cover Crop

There are two main ways to seed a cover crop:
Drilling
Some important components of the drill are the seed cup, disk opener, hopper, and press wheel. There are a few adjustments that need to be made each time the seed drill is used.
First, it’s important to know the size of the cover crop seed that will be used. The seed cup can be adjusted to slow down or speed up the seed distribution. Also, there is a disk opener that can be set for the appropriate pounds/acre seeding rate. 
An important thing to also note is the hopper gauge that can be seen by the tractor driver. This will show when the hopper is empty, and more seed needs to be added. 
There is also a cutting blade that can be used in no-till vineyards. If the vineyard is tilled in the spring, it’s important to keep in mind what will be used in the fall. That way the ground can be appropriately prepped for the next seasons seed.

Broadcasting
A seed broadcaster is the other commonly used method. It’s similar to smaller seeders that you can buy from any home and garden store. There is a setting for seed size and distribution is usually determined by the speed of the ATV. 

Benefits of Cover Crops

Cover crops are vital for any Integrated Pest Management program. Flowering plants are a great way to establish an insectary. They attract beneficial insects and encourage biological pest control. The diverse plant population can build general predator populations to suppress these unwanted insects and mites.       

Cover crops can be used to manage soil nutrients. For example, certain non-leguminous species can act as catch crops, removing any excess nitrogen to avoid leaching of this nutrient to the groundwater, whereas leguminous species can be used to capture atmospheric nitrogen, and turn it into plant-available forms of nitrogen in the soil. The choice of plant species and the management of the cover crop growth are the most critical decisions that will affect the outcome of this practice for soil health.