By Sjoerd Willem Duiker
No-tillage has many benefits such as soil erosion control, moisture conservation, soil health improvement, greater timeliness, time and labor savings, and energy savings. These benefits get elevated when we think of forage establishment considering the small seed size of forages such as alfalfa, red and white clover and perennial grasses. If established with tillage, a fine seedbed is required, which often necessitates multiple passes with tillage equipment and excessive soil pulverization, with all its ramifications. Fortunately, obtaining an excellent no-till stand is now achievable with a variety of quality no-till drills on the market. But there is more to it than just having good equipment. You need to plan ahead by choosing the right species, getting your soil fertility right, controlling previous vegetation, and residue management.
When starting with no-till forages, make sure your field is table-top level. Sometimes there are old plow furrows or other unevenness in the field, compromising drill depth control for many years into the future. Make sure the species you plant are adapted to your soil type (for example, alfalfa is not adapted to wet soils). Take a soil test and correct pH and fertility according to recommendations (this should have been done in the fall for spring seedings). Existing vegetation needs to be totally dead. Forages are not aggressive starters so existing weeds or sod may easily outcompete the young seedings. Killing a cover crop such as rye or wheat with herbicide can be challenging when temperatures are low. That is why it is often preferred to plant spring no-till forages after a winter-killed cover crop such as oats.
It is preferred to not have very heavy residue cover as it becomes challenging to get good seed to soil contact and depth control. Good scenarios for no-till forage establishment are after small grain harvest where straw has been removed, or after corn silage or soybean harvest, but it is hard to get a good forage stand after corn grain harvest due to heavy stover. Make sure that chaff and residue from the previous crop is spread uniformly. A common failure with no-till forages is to have swaths of heavy residue next to zones without residue due to poor residue distribution behind the combine which makes it impossible to get seed depth right. Finally, respect herbicide rotational restrictions – residual herbicides from the previous year can negatively affect your forage establishment.
When choosing a drill, make sure it is suited to plant the species you intend to use. The drill needs to be able to plant the seeds no deeper than ¼- ½ inch deep so good depth control is essential. Because of small reserves for emergence, the seedlings usually die when planted too deep. Some drills have a depth control wheel several feet behind the opener disks, which can cause problems if the field has some unevenness because the depth control wheel may be in a small depression causing the disk opener to dig too deep into the soil, or on a tiny hill causing the seed to be dropped on the soil surface. In fact, the seed drop tubes from the small seed box typically drop the seed behind the disk openers instead of between them to avoid planting them too deep. The press wheel than gently presses the seeds into the soil. Other drills have a depth control wheel next to the opener and do not have as much of a problem with depth control.
It is good to occasionally see a few seeds at the soil surface after planting; that means you are not planting too deep. It is also important to check that all seed tubes are connected and open: check for spider webs, mice, or other things that may block seed flow through seed tubes. Also, check that the metering system is in top shape – some drills use sponges for metering, and we have learned that mice like to chew through them in search for some food in the winter! If you plan to plant fluffy seeds such as smooth bromegrass or warm season grasses in the future, make sure the drill has agitators inside the seed box to avoid bridging of the seed. You also need large diameter seed tubes for these seeds to avoid bridging. Another option is to mix the fluffy seeds with other seeds to avoid this. Further, coulters and disk openers all need to be in top shape so check on wear and make repairs as needed.
With proper planning, no-till forage establishment can be very successful. In fact, producers experience that with no-till forages near surface soil moisture is conserved and that seeding depth is more easily controlled than in a tilled soil (especially when the seedbed is cloddy). The soil therefore does not dry out as quickly as with tillage, and less seed is wasted due to improper seeding depth. Add to that the other benefits of no-till and this practice becomes a true winner.
Source : psu.edu