Should I plant green or not?
Planting green – when a cash crop is planted directly into a still-growing cover crop, instead of terminating the cover crop first – always sparks a lot of conversation. Some farmers are big proponents, while others are more skeptical. Based on preliminary data from our SHP farmers, approximately 37% planted green in spring 2020 (although, in some states, it was as high as 75%), which is an increase from 2019.
Over the course of this three-part blog series, we will be sharing considerations for planting green, benefits and drawbacks to this practice and – if you do choose to plant green – what you should keep in mind from an equipment standpoint.
Remember: soil health approaches, including whether or not to plant green, should be based on your farm goals and practical logistics. With the information in this series, we hope to provide the information that helps you feel more confident in making those decisions.
Why do farmers plant green?
After decades of planting into a clean seed bed, you might be wondering: Why would farmers want to plant while there’s still another crop in the ground? The reasons are many, but here are a handful of the ones that come up most frequently:
- A farmer misses the window to terminate (kill) the cover crop, leaving too much undecomposed residue on the surface and complicating planting.
- You want to maximize cover crop biomass to help with goals of building organic matter in the long-term.
- To ensure that early season troublesome or herbicide-resistant weeds have as much competition as possible before your herbicide plan goes into effect.
- To increase water infiltration by allowing for more root growth.
- In wetter fields, planting green may help soils dry out since much of the moisture will be pulled up into the plant for a longer period of time.
- You can do one less herbicide pass, since you don’t have a pre-plant burndown pass.
- You can get out in the field sooner if the field has drier soils, due to the cover crops pulling out excess moisture.
There is also the possibility that planting green may lead to warmer soils in the early spring; we are gathering data on soil temperatures as part of our SHP Field Check process to better measure this.
What are the benefits of planting green?
Among farmers who have planted green – either on purpose or because of timing pressures – they have seen several benefits, both around soil health and from a logistical standpoint:
- Soil health improvements, including:
- Higher organic matter when biomass is maximized
- Increased soil respiration, soil carbon and more active microbial communities
- Living roots year-round provide food source for microbes
- Farmers are able to plant sooner when soils are warmer and drier earlier in the spring
- When soils are covered nearly 100% of the time, some farmers are seeing weed control benefits since the cover crop competes with noxious weeds
- Erosion control comes from having living roots in the soil nearly all year long (depending on the time of cover crop planting in the fall)
- Better habitat for pollinators like insects, butterflies and birds
- Allowing cover crops to salvage essential plant nutrients longer with deeper roots can bring those nutrients into the root zone earlier in the season so the cash crop can access them
What are some of the drawbacks of planting green?
While there are benefits to this approach, there are also some drawbacks that should be considered in terms of how they impact your farm. These include:
- You may have to adjust or invest in equipment. (We’ll be going into this further in a future post.)
- There is the possibility that you miss the right termination window, which could cause problems with cash crop emergence, or you don’t fully terminate the cover crop and it persists through the whole growing season.
- You may find there is a lack of knowledge about planting green in the local agriculture community to help you troubleshoot, so you might have to reach out beyond local agronomic experts.
Planting green isn’t for everyone, but it does have benefits for some farms. Consider how this information matches up with your goals and logistics. Is planting green worth thinking about, or does it not fit your management system? And, in our next post, Keith Byerly will be sharing the equipment considerations to take into account if you do want to plant green.