This article is based on two accompanying articles by Jeff Carter and Kristin Williams in our Summer 2021 Newsletter. Read the full articles on page 6 and additional info from Kirsten Workman on page 1.
Adding carbon to agricultural soils is being tossed about as the preferred currency for extra payments to support farms, improve soil health for better crops, hold precious rainwater, and reduce those pesky CO2 greenhouse gases (GHG) in the atmosphere which are hurting our planet. This leaves farmers and service providers asking, “how much carbon should we be trying to add to our soils?” The short answer is, “as much as you can.”
Right now, the Vermont Climate Council, the Payment for Ecosystem Services (PES) workgroup, and the Addison County Climate and Economy Action Committee (CEAC) are all discussing the values of increasing carbon in farm fields, for short-term income, long-term soil base preservation, and GHG mitigation. Easy to talk about, but much harder to accomplish if you are a farmer.
The University of Vermont is in the process of soil health testing, including measuring carbon for multiple projects. This include a Conservation Effects Assesment Project (CEAP) lead by Joshua Faulkner with support from our team, which is a long term water quality project in Addison County. Allison White is conducting a ‘State of Soil Health’ survey of farms across Vermont. Joshua is also leading another initiative looking at soil health and climate.
Perennial crops can be hard to target for nitrogen (N) applications, as the decision often depends on stage of establishment and species composition. Both factors change over time and adjustments should be made from season to season, or even within the same season. Below are factors to consider when trying to target the most efficient use of manure-based and purchased nitrogen in your perennial crops.
Species Grass and legumes (alfalfa, clovers, trefoil) each have very different nitrogen needs. Grass crops will respond readily to both manure-based and fertilizer-based nitrogen. Grass species not only reward adequate N supply with increased yield, but also increased quality. Applying up to (and sometimes over) 200 pounds of nitrogen per acre on grasses almost always yields an economically viable response. Legumes, on the other hand, do not need additional nitrogen from manure or fertilizer. Legumes have a fascinating symbiotic relationship with a soil-borne bacteria known as rhizobia. Rhizobia fixes atmospheric nitrogen in nodules on the roots that it colonizes, and then transforms it into plant-available nitrogen. As a result, a clear stand of clover or alfalfa would not need additional nitrogen fertilizer or manure to reach maximum yield or quality. However, very few hay or pasture stands in Vermont are 100% grass or legume, and most farmers want a combination to maximize the benefits of species diversity and production. In these cases, we adjust the recommended nitrogen application rate to maximize production but still encourage the legumes in the stand to fix nitrogen. Fixing nitrogen is a trade-off for the plant, which shares carbohydrates with the rhizobia. This means that if extra nitrogen is available, plants can become “lazy” and not invest energy in that association. Additionally, a mixed stand with legumes that is treated with N up to the grass rates will encourage a shift of dominant species towards grasses as the grasses begin to outcompete the legumes.The table below shows how the nitrogen recommendations change depending on the legume content of the stand. In this case, grass is defined as any stand with less than 30% legume.
Split Applications Because N is mobile (both in the soil and the plant), it is important to split applications to maximize uptake by the plant and reduce losses. With hay and pasture, fortunately, we take multiple harvests and have the opportunity to split applications into reasonable amounts to be utilized by the crop over the course of the season: • Grass: split applications into 50 to 75 pounds per acre increments, ideally following each harvest. • Mixed stands (30-60% legume): one single 40-pound application; if applied in early spring, a second 40-pound application may be beneficial.
N During Establishment (New Seedings) Nitrogen fertility is not recommended for establishing legumes and mixtures. The exception is when a small grain is seeded with the legume or mixture. In this case, a 30 pound per acre application is recommended to get the companion crop up and growing ahead of the weeds. For a new grass seeding, the following recommendations apply: • 50 pounds per acre for a spring seeded crop. • If more than one harvest occurs in the seeding year, a second application of 40 to 50 pounds should be applied. • Late summer seedings only need 30 pounds per acre.
Reducing Needed N With Maintenance of Legumes If nutrients are limited and you are trying to reserve manure-based nitrogen for crops like corn or pure grass, take steps to maintain legumes in your stand. This will reduce or eliminate the need for manure or purchased nitrogen. Strategies to help maintain legumes include:
Maintain higher soil pH (6.8). • Leave adequate crop residual between cuttings, but especially after your last cutting. • Consider a less intensive cutting schedule to ensure adequate regrowth between harvests. Time your last harvest to allow for adequate regrowth before frost. • Monitor and maintain adequate potassium and boron levels in the soil.
At the end of the day, managing nitrogen resources on hay and pasture crops will pay off. A well-fertilized grass crop will pay you back in most years. However, manure is especially tricky, as it is easy to overapply N on mixed stands and this can contribute to legumes becoming less competitive, leaving the stand open to weeds. If you want to maintain legumes, back off on N and manage for legumes. Split applications for the best effect and, if possible, utilize low disturbance injection to really make the most of N in manure applications.
Making nutrient management decisions systematically on your farm and keeping good records is all part of having a nutrient management plan. Even without a formal plan, you can make informed decisions based on these basic principles. We are here to help farmers optimize yields and manage their inputs wisely.
*All recommendations are from “Nutrient Recommendations for Field Crops in Vermont” (September 2020, https://go.uvm.edu/br1390). For specific recommendations, consult your crop adviser or call Kirsten for more information. If you would like help managing nutrient application rates, or have other related nitrogen questions, contact Kirsten at firstname.lastname@example.org or 802-338-4969 ext. 347.
In Vermont sign up deadline for all 2021 EQIP contracts is March 19, 2021.
You can still sign up for EQIP after that, but you will be considered for next year.
VT Natural Resource Conservation Service (NRCS) has announced a top ten “high-priority” list of Environmental Quality Incentive Program (EQIP) practices. The state chose these practices to motivate producers to implement important practices that address critical resource issues but that are not as widely adopted. This is part of the 2018 Farm Bill – states were allowed as of 2020 to provide increased payment rates for up to 10 high-priority practices. These practices will be incentivized at a 90% cost payment rate. In consultation with each state’s Technical Committee, the State Conservationists designates their state’s priorities.
In Vermont, the ten priorities are: Contour Buffer Strips (332), Cover Crop – multi-species only (340), Residue & Tillage Management – reduced-tillage (345), riparian forest buffer (391), Pasture and Hay Planting (seeding down continuous corn) (512), Open Channel (582), Stripcropping (585), Nutrient Management (manure injection only) (590), Tree / Shrub Establishment (612), Phosphorus Removal System (782).
Some of these practices are probably more familiar to our audience than others, like reduced tillage. Other practices like stripcropping offer soil conservation benefits particularly on steep slopes, but are not commonly seen in our area. Open Channel refers to a two-stage ditch, and Phosphorus (P) Removal System is the installation of an end-of-pipe filter system to mitigate P losses in tile drains.
If you are interested in signing up for one of these practices, call your local NRCS office, in Middlebury – 802-388-6748. You can also call our office – 802-388-4969, if you’d like to discuss how we might assist you in getting a project implemented. NRCS accepts applications on a rolling applications but processes them in batches, sign up deadline for 2021 practices is 3/19/21.
Newsletter Highlight From Grassland Manure Injection: By The Numbers (pg. 4) With funding from VAAFM’s Clean Water Fund and the help of Ken and Debbie Hicks at Hicks Equipment, we purchased the right equipment from the Netherlands. With the expertise of Eric Severy of Matthew’s Trucking to operate it, we began demonstrating the utility of this system. Shallow slot grassland manure injection gets liquid dairy manure just two inches below the soil where it is protected from runoff during rain events while still well within the root zone where the plants will use it. Read More
Save the Date: 2021 No-Till Cover Crop Symposium March 4-5, 2021. More information coming soon. We’re joining forces with the Northeast Cover Crop Council to bring you a full day and a half of information related to no-till and cover cropping. go.uvm.edu/ntccs If you missed this year’s symposium you can also read presentation pdfs and the proceedings online.
As of right now, the UVM Agricultural and Environmental Testing Lab is still receiving manure and soil samples directly and the lab in Maine that UVM works with us is still open. However, we will not be transporting samples from our office in Middlebury to the lab in Burlington. Additionally, please understand that the manager of the lab will not be in the office every day and there many be an additional delay in processing samples. Call the lab at 802-656-3030 if you have questions.
Manure Samples: It’s nearing time for manure spreading… and also manure sampling! The best time to sample manure to get an accurate sample is right when you are about to spread it.
We ask that you sample, freeze and hold on to manure sample(s) for a future date
to be analyzed when we can transport it to the lab. Manure can be sent
in the mail, but it’s more ideal to just hold on to it. If you need a
timely result, call the lab, you may be able to send it directly to
Manure can be frozen for months, just make sure you leave enough space in the jar for expansion.
manure jars will be left in the sample box at the entrance of our
office, but any plastic quart jar could work – do not use glass jars.
Our fact sheet on how to take a manure sample can be found here.
The form for manure sample analysis can be found here.
While we recommend soil sampling at the same time each year, given circumstances, if you can wait to sample it is advised to do so. If you do need an analysis, you can direct mail your soil sample(s).
There will be soil test kits left in the sample box at the entrance of our office, but any clean sandwich type plastic bag will work. You only need 1/2 to 1 cup of soil per sample – over doing it doesn’t help the lab and costs you money. Just make sure you take adequate sub-samples, mix your soil sample well, and send a representative mix. Soil probes will not be available until a future date.
The form and instructions for soil sample analysis can be found here.
If you have any questions about manure and soil sampling you can still give our office a call, and someone will get back to you – 802-388-4969.
Did you know you need to update your NMP every year to stay in compliance with the State of Vermont Required Agricultural Practices (RAPs)?
If your plan is out of date or you need assistance in updating your nutrient management plan, UVM Extension can help!!
If you took a NMP class through UVM and designed your plan in goCrop, please call the office where you took your original NMP class, or contact your closest location (listed below). You will need manure sample results every year, soil sample results every three years, and field records of the activities you performed annually. You may also need updated rotation calculations, depending on your situation. UVM Extension can help you identify everything you need and walk you through the process of getting it accomplished.
The three locations that can help you are:
Middlebury Extension Office – 802-388-4969 or 1-800-956-1125
St. Albans Extension office – 802-524-6501 or 1-800-639-2130
St. Johnsbury Extension office – 802-751-8307 or 1-800-545-8920 (800 numbers toll free in Vt.).
At Middlebury UVM Extension Office
23 Pond Lane Suite 300, Middlebury, Vt
we are holding update sessions on the following days:
These sessions are for folks who have already taken a class with UVM Extension. If you have not taken a class with us, but would like help, give us a call.
Our sessions are informal. Please bring a lunch or snack if you need it to keep you going!
We have laptops, or you can bring your own. Remember to bring your NMP binder along with any records and documentation, including your login information. If your goCrop account is out of date you will need to renew your subscription with debit or credit card. If you have any other paperwork that is related to an updated NMP, such as MFO/LFO permitting, bring that along too. If you have new fields, you will need new maps and field information, including yearly and average RUSLE2 calculations.