Using a Kreger Farms Invented Interseeder to Profitably Plant Cover Crops into Varying Corn Growth Stages

Final report for FNE20-956

Project Type: Farmer
Funds awarded in 2020: $7,859.00
Projected End Date: 06/30/2022
Grant Recipient: Kreger Farms
Region: Northeast
State: Pennsylvania
Project Leader:
Heidi Kreger
Kreger Farms
Expand All

Project Information


Cover or double cropping in northern, mountainous regions of Pennsylvania is not widely practiced, and it puts area farmers at an economic disadvantage as compared to their peers with more favorable crop growing conditions.  Unanswered questions and equipment unavailability make it tough for Northern farmers to profitably adopt cover cropping on corn grain and silage acres.

This project addressed if a Kreger Farms styled interseeder would profitably plant cover crops into standing corn. Initially we varied what corn stage we interseeded into, but it turned out that moisture decided when we could interseed successfully, and what mixtures worked best. The interseeder went over reproductive corn (with very little damage) using seed mixtures of cereal rye, triticale, ryegrass, radish, and black oats. The triticale/tillage radish mixture (2020 planting) provided additional high quality forage in 2021, while the black oat/tillage radish mixture provided an excellent manure hauling location in wet weather in our bi-weekly manure hauling system. 

The Kreger Farms styled interseeder has been seen in FARM SHOW magazine,  even being the first story in their The Best of FARM SHOW 2021 Edition. This project, FNE 20-956, was selected to be included in the Farm Innovation Show at the 2022 PA Sustainable Agriculture conference. 

What we found most impressive about our outreach was that farmers who have been farming for a long time using the same methods every year were very interested in our project and results. Two older farmers even have plans to interseed some of their fields!

Project Objectives:

The question we will answer is “Can broadcast interseeding using an inexpensive Kreger Farms interseeder be done successfully? Success is determined by percent cover after harvest and at spring time, and minimal yield loss. We want to know what cover crop species in what planting conditions will survive being broadcast into a corn canopy, have harvesting equipment stress it, and contribute to the field’s cover crop goals. We want to be able to make recommendations to other farmers with similar growing challenges as to what species to plant, under what conditions to plant, using a Kreger Farms styled interseeder. If this project is successful, more farmers will adopt or be able to borrow, a Kreger Farms styled interseeder to maximize their cover crops usage, and their overall land. More farmers would be able to enjoy the benefits of nutrient recycling, soil conservation, soil resiliency, a cheap and high clearance machine to increase their soil productivity and farm cash flow.


Successful cover cropping is a necessity for farms to reduce their environmental footprint and be profitable. Many northern Pennsylvania areas have shorter growing seasons than areas where cover cropping is widely researched. This experiment will be conducted at approximately 1800 feet elevation in contrast to the Ithaca area at 400 feet elevation and State College area of 1200 feet.    

Many times corn silage in Northern Pennsylvania is harvested well into October, making proper cover crop establishment after harvest difficult to achieve. Cover cropping on grain corn after harvest is not realistic. Cover cropping provides many observable benefits to producers, including extra forage, retains fertilizer nutrients that would ordinarily be lost and improving soil structure to better handle water challenges farmers are facing more and more of.

If farmers in our county could improve their cover crop establishment, we could reduce topsoil loss, increase nutrient recycling and retention, and increase soil resiliency for only the cost of cover crop seed and minimal equipment and fuel. These benefits make our farm more sustainable by increasing cash flow potential, reducing fertilizer dollars lost, and making our soils more productive.

This farmer driven research project is aimed at northeastern farms in higher elevations with poorer soils when compared with typical research sites in Pennsylvania and New York.

When Kreger Farms started refurbishing the JD 6000 sprayer into an interseeder, six local farmers expressed interest in using the machine, Craig Williams, Penn State Extension Agent calibrated the machine, and FarmShow Magazine featured our interseeder in their February 2020 edition. Also, NRCS personnel have expressed the need for timely cover crop planting. 

The Kreger Farms developed interseeder was very cheap and simple to make, as compared to an $80,000 plus commercial highboy. It cost a total of four thousand dollars and took approximately two days to build. Being inexpensive means more farmers can make their own interseeder and have increased access to a machine that can plant cover crop as the farmer’s time or budget allows, because this interseeder can go over mature corn. This allows farmers to plant field by field, crop by crop, and on varying time schedules. Being able to plant in mature corn allows a farm greater planting options. If a farmer does not have time at V5- V7 stage, the machine can still go over mature corn and cover crop can still be seeded before harvest. The Kreger Farms interseeder uses a spin spreader that can cover twelve rows (30 inch corn rows). Having planting flexibility also allows a farm to reduce any herbicide or nitrogen injury to cover crops.


Description of farm operation:

Zach and Heidi Kreger own and operate Kreger Farms, a 70 cow dairy in a the PA Wilds region. Zach graduated from Penn State University in 2011 and Heidi in 2013 both with agriculture degrees. Kreger Farms has been in business since 1943, and since 2014, it has been under Zach and Heidi's management.

We farm 350 rented and owned crop acres: 80 acres of corn silage, 60 acres of grain corn, 40 acres of small grains, oats, wheat, or barley, 170 acres of either mixed grass haylage or dry hay. This produces our high quality forages and grains which we feed our dairy cows. Their rolling herd average is 26,000 pounds on a 60% forage and 40% concentrate ration. Our milk is contracted through Dairy Farmers of America.

We are firm believers in Tom Kilcer's motto "It is the crops that feed the cows, that make the milk, which creates the money." (Tom Kilcer from Advanced Ag Systems) In order to have high quality crops, we need high quality soil that can handle wet or dry challenges. Kreger Farms has been no-till with cover crops since 2010. Many of our fields have soil organic matter 4% to 8%, much higher than the PA average of 2%. Traditionally we drill our cover crops after corn silage harvest, but have had mixed results and it limits what species you can plant. in 2018 the Bradford County Conservation District bought a commercial highboy interseeder to trial on farms. This gave Zach's dad, Jim, the idea to make our own interseeder using a converted John Deere 6000 high boy sprayer and putting a seed broadcaster on the back.


Click linked name(s) to expand/collapse or show everyone's info
  • Craig Williams - Technical Advisor (Educator)


Materials and methods:

We plan to conduct this research experiment in Morris, PA. The Kreger Farms designed interseeder will plant the cover crop seed. Zach Kreger (farm manager) will be the driver and oversee seed mixing. Heidi will assist by opening and closing the seed broadcaster. Cover crop seed will come from the Local Seeds Facility in Jersey Shore PA. Kreger Farms has their own seed mixing equipment and scales. The radish used was Local Seeds tillage radish. 

The interseeding plan is:

V6 Interseedings                                                                                                                                            

  1. 100 lb/acre Cereal rye and 5 lb/acre radish in corn grain and corn silage.
  2. 25 lb/acre Annual ryegrass and 5 lb/acre radish in corn grain and corn silage.

V12 Interseedings                                                                                                                                          

  1. 92 lb/acre Cereal rye and 8 lb/acre radish in corn grain.
  2. 25 lb/acre Annual ryegrass and 5 lb/acre radish in corn grain.
  3. 92 lb/ acre Triticale and 8 lb/acre radish

Reproductive Interseedings                                                                                                                                                    

  1. 92 lb/acre Black Oats and 8 lb/acre radish in corn silage.
  2. 100 lb/acre wheat and 5 lb/acre radish in corn silage and corn grain.

Interseeded acres will total 100 depending on corn planting conditions and final crop rotation decisions. Monthly height and dry matter estimations will be taken by Heidi Kreger. A USDA Pasture ruler will be used to measure height and dry matter, and pictures to document. We will conduct corn tissue sampling between tasseling and silking. By this time nitrogen will be sidedressed and corn will be nearing the end of its nitrogen uptake. We can compare the tissue sample results to what fertilizer was applied and see what may be available for the cover crop. Corn yield comparisons will be done. Silage will be measured in tons. The forage wagons are already calibrated and each field yield is normally analyzed.

2020 and 2021 Modifications

Due to drought in 2020 and excessive moisture in 2021, and unforeseen labor needs interseeding (we needed 2 people to interseed), we did not have as much time as we thought we would to interseed. We pivoted to getting highest priority acres completed, which was silage corn. If the growing season allowed, as late in 2021, grain corn was interseeded. 

Also, we did not corn tissue sample. It added another data point that increased project complexity. In the future, we intend to corn tissue sample as part of our own farm's crop nutrient budgeting. 

Research results and discussion:

2021 Final Data and Discussion

In a very wet 2021 a total of 47.5 acres of corn silage and corn grain was interseeded into. 4.5 Acres of the total had no cover crop growth in either the fall or spring due to heavy weed pressure, marestail. (Separate from this project, Bradford County Conservation District interseeded 12 acres of ryegrass/radish that had moderate bedstraw pressure, only the radish grew.) The other acreage had either vigorous fall growth or spring, not both.

Black oat had tremendous fall growth that minimized soil erosion, but it winter-killed and only provided a weed suppressing mat in the spring. Wheat had some fall growth. We were disappointed with it from a soil erosion standpoint, but by the time spring growing season was underway, the wheat tillered enough to keep it. It yielded 35 bu/ac. Our drilled field nearby yielded 60 bu/ac. Overall the wheat had poor germination in the excessive moisture conditions, as compared to our other cover crops, interseeded and drilled. The triticale/radish mix did not have fall growth being planted November 1, but in the spring it grew, from being sparse to 80% dry matter estimation of the field. It helped decrease weed pressure. 

The 2020 interseeded triticale was the only cover crop we saved for a forage. Cover crops for forage do not fit our crop rotation well, but this was an unusual case where they did. We chopped the triticale May 25, 2021, and were pleased with it's nutrient test. The triticale had 14% crude protein and 14% sugar.  Whereas our haylage mix of orchardgrass, fescue, and alfalfa, was past peak quality at this time, the triticale was at its peak at chopping. This gave us some "rocket fuel" forage to complement our traditional haylage. 

In 2022 we have plans to interseed a mix that has vigorous fall and spring growth in our corn silage. Due to drought conditions, we are waiting for soil surface moisture. If interseeding gets later than August or September, we plan to use bin run seed where possible, and seed at 120 lbs/ac. 

2020 progress:
     Progress and data NESARE update Jan2021
     Video of interseeded field

2021 progress: NESARE 2021 update

Four interseeded fields, and one control drilled field are currently used in the 2021 data. 2021 Growing conditions were opposite of 2020.  July, August and September saw 8.3, 6.29, and 6.87 inches of rain, respectively. The heavy clay soils took many days to dry out. Rain and sunlight are somewhat inversely related. 2021 Had about 5,000 less Langleys of sunlight than the 2020 growing season (using the closest weather montoring station with complete sunlight data, Hegins, PA). Rain also brought another issue for farmers trying to interseed: time. The few sunny, drier, plantable days are filled with the routine, cash crop activites. Corn grain fields had no fall cover crop growth, to be expected planting triticale November 1. Corn Silage updates are as follows:

Field 1 (HM5) : Interseeded August 11 with 92 lb rye and 8 lb radish. Growth was inconsistent across the field. A 100 foot swath, with tile drainage, had 60% cover. Everywhere else was bare. Rye seed even sprouted on the corn plant. 

Field 2 (HM1) : Interseeded August 15 with 92 lb triticale and 8 lb radish. Triticale grew to 10 inches tall, while the radish grew to about 6 inches above ground and 5 inches below ground. Dry matter estimation was 80% by the end of the season. 

Field 3 (HM3): Interseeded September 8 with 92 lb Black Oats and 8 lb radish. This field had the greatest cover and height. The Black Oats were 12 inches tall by the end of the season, and dry matter estimation was 100%. Kreger Farms has a semi-weekly manure haul. During muddy conditions in late fall 2021, we were able to spread 4000 gallons of dairy slurry without tracking up the field. 

Field 4 (Willis 4): Interseeded September 16 with 92 lb wheat and 8 lb radish. The wheat grew to about 3 inches tall, radish was about the same. Dry matter estimation was 50%. This is a very wet field, but Zach thought it planted well. For a winter soil cover , we were disappointed with it, but in the spring it filled in and we plan to cut the wheat July 30, 2022. 

Control field (W. Triangle): Drilled 92 lb wheat and 8 lb radish September 18 after corn was chopped.  The wheat grew to 8 inches tall and 90% dry matter estimation. This field is directly above field 4 on a hill. It had tremendously better soil coverage. The plan is to harvest the wheat July 30, 2022. 


Research conclusions:

Before starting our project, there were 3 actions we sought to accomplish: plant all our corn acreage, using 100 lb/ac of cover crop seed, at varying corn growth stages.

  1. In the project, the decision to interseed was driven by moisture. In drought conditions, wait until there is some soil surface moisture. In wet conditions, wait until a non-rainy day to interseed. This added another challenge, because non-rainy days were filled with normal cash crop activities and extra labor wasn't readily available.
  2.  We did interseed 100 lb/ac of cover crop seed. That rate met our growth goals. Plus, small farms typically have smaller fields. Many of ours range in size from 2 to 6 acres (we practice contour stripping). The seeder holds about 400 pounds and interseeds 4 acres on a fill. 
  3. One negative to the Kreger Farms invented interseeder is it takes 2 people to operate, 1 running the machine and 1 to open and close the seeder. In 2020 we interseeded 34.6 acres out of about 120 total (28% of total).  In 2021 we interseeded 47.5 acres out of 140 (34%).  (What silage corn we did not interseed, was then drilled into after harvest.)    

Our project objective had three parts, interseeding cover crop success being defined as greater than 75 % cover at harvest and spring, and minimal corn yield loss. If moisture conditions were adequate for germination, cereal rye, wheat, and black oats met the objective for harvest success at varying interseeding dates. Triticale did not meet 75% harvest cover at harvest unless it was interseeded in August. In spring, cereal rye, wheat, and triticale met objective. Black oats winterkilled.  Across all interseedings we did not see a corn yield loss. Larger factors, such as deer pressure and moisture, determined corn yield loss. 

While experiment results were positive and negative based on what species was interseeded and when, Kreger Farms will interseed a cover crop mix.  We will include a vigorous fall growth species for winter soil erosion and a vigorous spring growth species for nutrient recycling and soil resiliency. These keys will help keep our cover crops profitable. Traditionally we are the first farm in our area planting corn. In 2021 we were one week earlier than our conventional till neighbors. 

Participation Summary
2 Farmers participating in research

Education & Outreach Activities and Participation Summary

3 Consultations
1 On-farm demonstrations
1 Published press articles, newsletters
1 Webinars / talks / presentations

Participation Summary:

40 Farmers participated
7 Number of agricultural educator or service providers reached through education and outreach activities
Education/outreach description:

March 30, 2022 Heidi and Zach presented at the 2022 Tioga County Soil Health Day. Approximately 40 farmers were in attendance, plus 7 NRCS and Conservation District personnel.  We discussed which fields planted well and what cover crop species we liked best. Since we have been no-till and cover crops for about 11 years,  we discussed our past results, and compared it to our current interseedering. PowerPoint presentation

Another farmer, Gary Keeney, saw our interseeder at this presentation and he came up with his own interseeder for his vegetable crops. He struggles with weed pressure in his pumpkins, and a cover crop mix with hairy vetch and black oat would alleviate some of this pressure. 

Also, at this meeting we spoke about SARE and what is needed for a Farmer Grant. 

July 2021 Andy Wodehouse, an NRCS engineer from Bloomsburg, PA, consulted with Zach as to the design and the results we saw. 

The Best of Farm Show 2021 Edition, a supplement to Farm Show Magazine, featured the Kreger Farms highboy interseeder on page 2.  We fielded 2 farmer phone calls following the article. 

This project was also selected to be included in the Farm Innovation Show at the 2022 PA Sustainable Agriculture conference. 

Learning Outcomes

3 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
Key areas in which farmers reported changes in knowledge, attitude, skills and/or awareness:

Knowledge: Interseeding (even general cover cropping) is a dynamic crop strategy that requires continual evaluation.  What works under certain conditions may not work the next year under slightly different conditions. You cannot be afraid to fail.

When conditions are not extreme, interseeding works excellent. When they are extreme, "The Plan" requires background knowledge of the fields (soil type, water flow, organic matter content, etc.) and a thorough understanding of the cover crop being planted (amount of sunlight required to germinate, hydrophobic versus hydrophilic root systems, etc.)

 Interseeding may also require some additional fertilizer. Kevin Brown, Bradford County Conservation District technician, has discussed with us there are 2 crops growing at the same time. In wet conditions, is there anything left for the cover crop to thrive on? What about decaying organic matter nutrients that are slowly available throughout the growing season?

Project Outcomes

4 Farmers changed or adopted a practice
2 New working collaborations
Project outcomes:

Kreger Farms will continue to interseed and experiment with different mixtures. We have had promising results from improved water infiltration and increased soil organic matter, up to 8%. For the 2022 crop season, we have not started to interseed yet. It has been dry, and from the lessons learnt in 2020, we are waiting until we get enough rain to start regrowth in the hayfields. We are ready to plant cereal rye and radish mixtures, and if we can interseed by September, black oat and radish. 

Gary Keeney, the vegetable farmer, has his own version of an interseeder for his pumpkins. 

Jim, a small, neighboring beef and crop farmer, signed up for the Conservation District's highboy interseeder. He saw the results from our project and would like to extend his pasture season for his beef cattle, by letting them graze the corn fodder and growing cover crop. 

A local hunting club has asked Zach, farm manager, to interseed their corn food plots with cereal rye. 

Kevin Brown, Bradford County Conservation District, told us that after the 2020 season he was frustrated with the results, and was not going to write another grant to pay for interseeding, but after seeing some of our 2020 results he decided to try again in 2021.

Assessment of Project Approach and Areas of Further Study:

Our project, Using a Kreger Farms invented interseeder to profitably plant cover crops into varying corn growth stages, had many moving parts, which seems to be typical for a cover cropping plan.

Looking back there were three keys to success. The first is our farm has two main cover crop goals, control soil erosion, and maximize nutrient retention. We want a living root in all of our soils as many days of the year as possible, and need a winter hardy cover crop to accomplish this. It narrows down our cover crop options. The second key is various interseeding dates. Not only does weather impact when to start, but so does current cash crop conditions, such as weed pressure and light penetration. The third key is using premixed seed, if using a mix. It helps streamline the process. 

One large challenge as a farmer doing their own interseeding, is labor. It took two people to operate the interseeder. A hydraulic motor that can open and close the door on the broadcaster would make it a one person operation. 

The question we set out to answer was, can broadcast interseeding using an inexpensive Kreger Farms interseeder be done successfully? Yes, it can be done successfully. It depends on timing the cash crop conditions, to weather, to a farms' cover crop goals.  At Kreger Farms, we will continue to interseed, but change to a mix with black oats, radish, and wheat, or rye. This mix's goal is both vigorous fall and spring growth. In the project, we had either incredible fall growth or spring, not both. 

The value of cover cropping (and no-till) is immense. This 2022 crop year has been dry. Our hay fields are green, and we plan to get a 4th cut, whereas neighboring farmers, who conventionally till, chopped 2nd cut and have brown hayfields now. Our soil organic matters are as high as 8%; many around 5-6%. In the spring-time, we can plant corn up to week earlier than farmers who plow. These benefits are well worth the extra task of interseeding and drilling cover crops in the fall, and we at Kreger Farms encourage other farmers to try it out. 

Additional work that both Bradford County Conservation District and Kreger Farms is looking at in the future, is a nutrient budget that includes cash and cover crop needs. Also, another item to work on is creating a blueprint, or checklist, or some format that farmers can print, or download that will  streamline a cover crop plan and allow farmers to make decisions quicker. 

The knowledge gained from these results would benefit corn growers who want to rotate beyond corn and soybeans, and dairy farmers looking for inexpensive ways to add a forage crop or small grain in their rotation, while gaining immense soil health benefits. 

Information Products

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.