Make plans to attend Fall Fest at the Haskell Ag Lab on Saturday, September 24th. The free family event will run from 1:30 to 4:30 p.m. Learn how honey is extracted, the use of cover crops in fall gardening, take a tour of the Northeast Arboretum and hear about the hazelnut project. The pollinator garden will also be featured as well as various products using beeswax. Activities for children include making butterflies and learning about Monarchs, a scavenger hunt, crafts with pumpkins and gourds, and other activities and games. Apple picking will be available as well as a photo booth to take pictures. We look forward to seeing you on Saturday, September 24th. Be sure and watch our website hal.unl.edu/fallfest2022 for any weather related announcements.
Factors to Consider Deciding When to Reseed Alfalfa
Mitiku Mamo is a Water and Integrated Cropping Systems Extension Educator serving Cedar, Dixon, Knox, and Wayne Counties.
As county-based Extension Educators, this time the year we get in-person visits and telephone calls from producers with concerns related to their row crops, pasture, and backyard garden operations. One such recent question from a producer was related to alfalfa autotoxicity. Pipes were laid through his alfalfa field, and he wanted to know if he can reseed that strip of land disturbed when the pipes were laid, with alfalfa. His concern was that the toxins from the established alfalfa may affect the germination and establishment of reseeded alfalfa.
A Michigan State University study states that alfalfa autotoxicity is a trait which causes alfalfa to be toxic to its own seedlings, the cause of alfalfa autotoxicity has never been fully explained, and alfalfa autotoxins do not affect any other crop.
Research also showed that autotoxicity is affected by several factors. Alfalfa releases toxic chemicals into the soil even after alfalfa is killed, be it by spraying or tillage. How long the toxins remain and their effect on the new seedlings depends on soil type, temperature, tillage, rainfall amount and time since termination.
For example, on sandy soils toxins are readily available and easily taken up but are less persistent because they leach quickly through the root zone. Irrigation and rainfall before reseeding help leach toxins out of sandy soil profiles after termination of old stand. Under dry weather conditions, delaying reseeding may be necessary because toxins from the terminated old stand may persist in the soil profile. On heavier soil, however, because the toxins are tightly adsorbed to soil particles, their effect is less but longer lasting. Hence, delaying reseeding, after termination, on soils containing clay is advised even under moist condition.
The level of toxins in the soil is also affected by tillage. Research in Wisconsin has shown the effects of autotoxicity to be greater in no-till fields than those that were moldboard plowed. Soil disturbance by tillage helps to better mix and dilute the toxins. Higher temperatures are known to break down the toxins more rapidly. Tillage may help toxin degradation by exposing them to high temperatures.
The time interval between terminating an old stand and planting a new one also has a significant impact on the effects of autotoxicity. A Michigan study showed that alfalfa could be successfully established two to three weeks after killing the old stand. In a Missouri study plant density of 2- and 3-week rotations were 13-20% lower than that of an 18-month rotation.
In our case, because the area to be reseeded is a strip within an existing alfalfa field, distance between the old and new alfalfa is another factor to consider. Research indicates that for seedlings to survive and grow normally, they have to be at least 16 inches from an existing alfalfa plant. The decision when to reseed, hence, depends on one’s particular situation.
Please plan to join us at the Haskell Ag Lab for Coffee and Conversations the 2nd Tuesday of each month at 9 AM. We will have coffee and snacks ready. The next Coffee and Conversations will take place on Tuesday, October 11th. Please invite friends and neighbors to attend with you. If you have ideas for presentations at Coffee & Conversations, please share with us.
Employee Spotlight
Chad Lake is an Ag Research Technician at the Haskell Ag Lab. Chad does general farm work and grounds upkeep. In addition, Chad works in the shop doing welding, repairs of various kinds, and service on the farm equipment.
Solar Electric for Farms, Home, & Businesses Workshop
The Haskell Ag Lab will be hosting this workshop on Tuesday, December 13th from 6 - 8 PM. Registration is open at the link on the flyer. Cost is $10. This will be a very informative workshop presented by John Hay, Extension Educator who has lots of experience with solar.
FALL GRAZING
Winter can be a stressful time for pasture plants, but sending them into the cold months ahead fully prepared will result in better growth when warmth returns next spring. With dry conditions already putting a strain on our pastures, how we manage this fall can have a big impact next year.
Plants and humans both use carbohydrates as a source of energy. However, unlike us, plants can’t carb load with a bowl of spaghetti when they need a boost, they have to produce their own energy. Typically, plants are able to do this just fine through photosynthesis, However, when temperatures get too low, like during the winter, or water is scarce during a drought, plants shut down their energy production and draw upon stored reserves to get by.
As we head into fall, plants sense cooler temperatures and shorter days and begin to build up energy stores to make it through the coming winter. Grazing in the late summer and fall impacts reserve build up in two ways, 1) by forcing the plant to remobilize already stored energy for regrowth and 2) by reducing the amount of plant leaf area, reducing its photosynthetic potential. Both impacts impart a level of stress on the plant at a critical time of the year.
This is especially true for grasses that have already been grazed in early and mid-summer. They have already been busy trying to restore leaf area and have lowered their reserves in the process. Similarly, plants already stressed by a lack of moisture have not been able to function at a high level and haven’t been able to build reserves up throughout the season like normal. In heavy drought situations, photosynthesis has been almost shut down completely, and plant has been using energy from the reserves instead of storing it.
So how do we manage animal needs, with plant needs when grazing pasture this fall?
1) Don’t over graze. The take half leave half adage has stuck around for a reason. Leave half of the plant’s overall growth in tact to maintain photosynthetic ability and reduce the need for regrowth.
2) Rotate pastures. Grazing the same pasture over and over again at the end of the year continually puts that pasture’s plants in a deficit as they head into winter. While plants can survive a few years of this, doing so over and over again decreases plant vigor. Instead, choose a pasture to graze last that has not be grazed yet this year, or has had adequate time for rest from an earlier grazing period. Pastures that have lower levels of drought stress are also a good candidate.
3) Utilize other forage sources. Late summer planted annual forages can provide early fall feed while crop residues and cool season annual forages can fill in the gap later on. Once cold temperatures set in, grazing dormant pastures can be done with lower impact on plant health and crop residues can be grazed without the high cost of harvested feeds.
4) Finally, plan for a sacrifice area if it is needed. Sometimes we just have to overgraze. However, we can choose where this will occur, how large of an area will be impacted, and how we want to facilitate recovery in the years ahead. While not ideal, with a plan, damage can be limited.
A dry year means giving pastures time to rest before winter is more important than ever. Take half-leave half, rotate which pastures are grazed last from year to year, and utilize alternative forage sources for a healthy pasture next year. If you do need to overgraze, plan to limit the damage and how to recover pasture health in the future.
-Ben Beckman is a beef systems Extension Educator serving the counties of Antelope, Cedar, Knox, Madison and Pierce. He is based out of the Cedar County Extension office in Hartington. You can reach him by phone: (402) 254-6821 or email: ben.beckman@unl.edu
Save the Dates for events at the Haskell Ag Lab Saturday, December 3 - Winter Fest - Save the Date - More details will be in October newsletter.
Late November/early December - Ag Budget Calculator Workshop. More details will be coming in future newsletters.
Suggestions/Requests
Do you have a suggestion or a request for a program at the Haskell Ag Lab? We want to hear from you.
Click this link and complete this form and submit. We will look at all suggestions and requests. The form is available at: https://go.unl.edu/halsuggest
You can also reach us by phone at 402-584-2261 with your suggestions/requests for programs.
