Importance of Cover Crops and Green Manure

The importance of cover crops and green manure in agriculture cannot be overstated. Cover crops, including summer cover crops and winter cover crops, are essential for preventing soil erosion and maintaining soil structure.

By planting cover crops such as sorghum sudangrass, Japanese millet, and hairy vetch, farmers can suppress weed growth and add organic matter to the soil. Green manure crops, particularly leguminous cover crops like sunn hemp, fix atmospheric nitrogen, enhancing soil fertility for subsequent crops.

Additionally, cover crops attract beneficial insects and improve soil moisture retention, providing numerous benefits to the soil and adjacent crops during the growing season. Effective cover cropping, therefore, plays a crucial role in sustainable agriculture by improving soil conditions and supporting the growth of cash crops.

Benefits of Growing in the Summer

Growing crops in the summer offers many benefits, particularly when using summer cover crops and green manure crops. Planting cover crops like sorghum sudangrass and pearl millet helps prevent soil erosion, improve soil structure, and add organic matter.

These warm season cover crops also enhance soil fertility through nitrogen fixation, benefiting subsequent crops and cash crops. Additionally, cover cropping in summer aids in suppressing weed growth and attracting beneficial insects, promoting a healthier ecosystem for adjacent crops.

The use of leguminous cover crops, such as sunn hemp, fixes atmospheric nitrogen, further boosting nutrient retention and soil moisture. Overall, summer cover cropping plays a vital role in protecting soil, supporting crop rotation, and ensuring sustainable agricultural practices.

Green Manure vs. Traditional Fertilizers

Green manure and traditional fertilizers offer different benefits and impacts on agriculture. Green manure, derived from cover crops like hairy vetch and sunn hemp, adds organic matter to the soil, improves soil structure, and helps fix nitrogen, enhancing soil fertility naturally.

Unlike traditional fertilizers, green manure crops suppress weeds, attract beneficial insects, and prevent soil erosion, making them a sustainable option for maintaining healthy soil conditions. Planting summer cover crops and winter cover crops as green manures also aids in retaining soil moisture and protecting soil surfaces from erosion.

While traditional fertilizers provide immediate nutrient availability, green manure crops contribute to long-term soil health, benefiting subsequent cash crops and crop species. Overall, incorporating green manures into crop rotation offers many benefits, including nitrogen fixation, soil moisture retention, and weed suppression, promoting a more sustainable farming system.

Understanding Cover Crops and Green Manure

Definition and Differences and Historical Background and Traditional Uses

Cover crops are plants grown primarily to benefit the soil rather than for harvest, while green manure crops are a type of cover crop specifically grown to be incorporated into the soil to add organic matter and nutrients.

Historically, farmers have used cover crops like hairy vetch and sorghum sudangrass to prevent soil erosion, improve soil structure, and suppress weeds. These crops are particularly effective in fixing nitrogen, enhancing soil fertility for subsequent crops. Planting summer cover crops and winter cover crops has been a traditional practice to maintain soil moisture and protect the soil surface during the off-season.

In contrast to cash crops, which are grown for profit, cover crop use focuses on long-term soil health and sustainability, attracting beneficial insects, reducing weed growth, and aiding in erosion control. Green manures, decomposing rapidly after soil incorporation, release nutrients that benefit subsequent cash crops and contribute to better soil conditions overall.

Benefits of Growing Cover Crops in the Summer

Soil Health Improvement and Weed Suppression

Growing cover crops in the summer offers significant benefits for soil health and weed suppression. Summer cover crops, such as sorghum sudangrass and pearl millet, improve soil structure and add organic matter, which is essential for maintaining soil fertility.

These warm season cover crop species also help to fix nitrogen, boosting nutrient levels for subsequent cash crops. Planting cover crops during the summer helps suppress weeds, reducing weed growth and competition for resources. Additionally, summer cover crops prevent soil erosion by protecting the soil surface, retaining soil moisture, and enhancing overall soil conditions.

By incorporating green manure crops like sunn hemp and leguminous cover crops, farmers can further enrich the soil, promoting healthier, more productive subsequent crops.

Pest and Disease Control and Enhancing Biodiversity

Growing cover crops in the summer provides crucial benefits for pest and disease control while enhancing biodiversity. Summer cover crops like Japanese millet and sorghum sudangrass attract beneficial insects, which help manage pests naturally and reduce the need for chemical pesticides.

Planting cover crops also disrupts the life cycles of plant diseases, decreasing their prevalence in subsequent crops. Additionally, a variety of cover crop species can promote a diverse ecosystem, supporting various organisms that contribute to soil health and fertility.

By incorporating green manure crops, farmers can add organic matter and improve soil structure, creating conditions less favorable for pests and diseases. The use of summer cover crops not only helps suppress weeds but also fosters a balanced, biodiverse agricultural environment that benefits both cash crops and soil health.

Types of Summer Cover Crops

Legumes

Leguminous cover crops are a valuable type of summer cover crop known for their ability to fix nitrogen and improve soil fertility. Examples of leguminous summer cover crop species include sunn hemp and hairy vetch, which are excellent for nitrogen fixation and adding organic matter to the soil.

These cover crops help suppress weed growth and prevent soil erosion, making them a good cover crop choice for maintaining healthy soil conditions. By fixing atmospheric nitrogen, leguminous cover crops enhance the nutrient content of the soil, benefiting subsequent cash crops and promoting better soil structure.

The use of these warm season cover crops also supports soil moisture retention and improves overall soil surface conditions. Incorporating leguminous green manure crops into crop rotation can lead to more productive subsequent crops and reduce the need for synthetic fertilizers.

Grasses

Grasses are a key type of summer cover crop that offers several benefits for soil health and erosion control. Warm season cover crops like sorghum sudangrass and pearl millet are excellent examples of grasses used in summer cover cropping.

These cover crops help prevent soil erosion by stabilizing the soil surface and reducing runoff. They also contribute to weed suppression by outcompeting weeds and reducing weed growth. Additionally, grasses can improve soil structure and retain moisture, making them valuable for maintaining healthy soil conditions throughout the growing season.

Incorporating grass cover crops into crop rotation supports the fertility of subsequent crops and helps protect the soil from summer heat and drought.

Broadleaf Plants

Broadleaf plants are a diverse category of summer cover crops known for their unique benefits to soil health and fertility. Common examples of summer cover crops in this category include buckwheat and sunn hemp.

These broadleaf plants excel in suppressing weed growth and preventing soil erosion, making them effective in maintaining a stable soil surface throughout the growing season. Additionally, green manure crops like buckwheat flowers add significant organic matter to the soil, improving its structure and moisture retention.

Unlike some other cover crop species, broadleaf plants are often drought tolerant and can thrive in varying soil conditions, enhancing soil fertility and supporting subsequent crops. Incorporating these good cover crops into crop rotation helps protect the soil, reduce erosion, and prepare it for future planting.

Timing for planting your cover crop

Most cover crops are planted in late summer, but there are some cover crop seed mixes that can go in the ground in the springtime and give you benefits by the end of the summer. Cover cropping is a cheap and effective way to fertilize your garden, hold topsoil in place, and retain moisture during the summer heat. Planting a cover crop on a fallow garden bed or farm field is a classic organic gardening technique. It also seems rather mysterious to those new to organic gardening. But it's simple as can be. The principle of cover cropping is to grow plants that will nourish the soil. If you cut down cover crops that have high nitrogen levels, and turn them into the soil (where they will break down) the cover cropping is called "green manure". In our video about green manure Tricia shows you how to till in, turn in, or compost a cover crop. You'll be adding more organic matter, which will improve soil structure over time, when you till in these green crops. We have the largest selection of cover crops, at the best prices, on the West Coast.

Planting in the spring for a summer cover crop

For a fast, warm-season cover crop that shades out weeds, buckwheat (shown above) would be a good choice. It germinates when the soil is 45-105°F and it is ready to till in in about a month. An all-around summer/warm weather cover crop is our Summer Soil Builder Mix. The mix contains buckwheat and cowpeas and if you inoculate your mix with rhizobacteria (Cowpea Inoculant or the Garden Combination), the cowpeas will fix nitrogen on its roots. The buckwheat accumulates insoluble phosphorus from the soil, and when turned under, releases it to the soil in a plant-available form. We have a great collection of summer cover crops. Go to our Warm Weather Cover Crop page for the complete list of seeds that grow in the warmth of the summer.

Choosing a cover crop for any season

Most home gardeners want to replenish nitrogen in the soil, since vegetables use lots of nitrogen when they grow and fruit. Have you heard of "nitrogen fixing"? That means the new nitrogen produced by the cover crops stays in the soil. You can see the nitrogen-fixing nodes on the roots in this photo. Legumes are good for adding nitrogen to soil, so many cover crop seed mixes are high in legumes. Legumes fix more nitrogen if you treat them with an inoculant before you plant them. The inoculant contains the naturally occurring soil rhizobacteria that are essential to nodule creation and the transfer of nitrogen back into the soil. Choose a cover crop that will grow well in your climate and the upcoming season. It's easy to find that information on our Cover Crop page. Click the link for Cover Crop Solution Guide, which sorts the seed mixes by when to plant them and what they do. Cover crops are not just for fixing nitrogen -- for instance, they can be effective clod-busters, providing cover for beneficial insects, choking out weeds and erosion prevention. Think about which soil problems you want to solve and then check our Solution Guide for Cover Crops to find out which seeds will do the trick for you.

How to plant a cover crop

1) Harvest your vegetables, then pull out the plants and other debris.

2) Calculate the square footage of the area you want to plant with cover crop.

3) Buy enough seed for the area (our Summer Soil Builder Mix is shown above).

4) Inoculate the seeds, if necessary, and plant them.

5) Water regularly if your cover crop needs summer irrigation.

Whether you plant in spring or late summer, the rule of thumb is to cut or turn in your crops when half of a cover crop stalk is in bloom.

Get your Advanced Organic Gardener merit badge when you grow a cover crop -- whether you plant in spring or late summer.

Conclusion

In conclusion, integrating cover crops and green manure into your farming or gardening practices offers substantial benefits for soil health and overall productivity. Whether you choose summer cover crops like sorghum sudangrass and buckwheat, or leguminous varieties such as sunn hemp and hairy vetch, these plants contribute to improved soil structure, fertility, and moisture retention.

They also play a crucial role in weed suppression, pest control, and biodiversity enhancement. By understanding the different types of cover crops and their specific advantages, you can make informed decisions that align with your soil conditions and crop needs.

Embracing these practices not only supports sustainable agriculture but also ensures a healthier, more resilient growing environment for future crops.

FAQs: Growing Cover Crops and Green Manure in the Summer

• What are the benefits of growing cover crops and green manure in the summer?

  • Growing cover crops and green manure in the summer helps protect soil from erosion, improve soil fertility, and suppress weeds. They can also add organic matter to the soil, support beneficial insects, and enhance soil moisture retention, which is particularly useful in drought-tolerant environments.

• Can summer cover crops be planted in sandy soils?

  • Yes, summer cover crops can be successfully planted in sandy soils. For example, buckwheat and sorghum sudangrass are well-suited to these soil conditions and help improve soil structure and moisture retention.

• How do summer cover crops affect subsequent cash crops?

  • Summer cover crops benefit subsequent cash crops by fixing nitrogen, adding organic matter, and improving soil structure. This leads to better nutrient availability and overall soil health for the following crop.

• When should I plant summer cover crops?

  • Summer cover crops are typically planted in mid-May or early spring, before the growing season gets too hot. This timing allows the cover crops to establish and provide maximum benefits before the onset of summer heat.

• What happens if summer cover crops are left on bare soil through the winter?

  • If summer cover crops are left on bare soil through the winter, they may be subject to winter kill due to cool weather and freezing temperatures. This can result in the decomposition of the cover crops, which still contributes to soil organic matter and improves soil fertility.

• How do green manure crops differ from winter cover crops?

  • Green manure crops are grown specifically to be incorporated into the soil to add organic matter and nutrients, whereas winter cover crops are planted to protect soil during the off-season. Green manure crops decompose rapidly, releasing nutrients and improving soil structure, while winter cover crops may help prevent erosion and improve soil conditions during winter months.