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

Progress 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
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Project Information


Interseeding cover crops into mature corn in northern Pennsylvania is not adequately represented in published research studies. Unanswered questions and equipment unavailability make it tough for farmers in these areas to profitably adopt cover cropping on corn grain and silage acres a common practice. This project will address what corn stage interseeding works best, and what mixtures work best while using the Kreger Farms invented interseeder. The interseeder will go over corn at the V6 , V12 and at silking using seed mixtures of cereal rye, ryegrass, radish, black oats, and crimson clover. These species are inexpensive and easy to obtain. There are three area farmers who are willing to participate in this project (50 additional acres total). The project will promote itself with road frontage signs, and a field day with Penn State Extension, NRCS and Conservation District personnel.

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. Successful cover crop establishment adds extra forage, retains fertilizer nutrients that would ordinarily be lost and improves 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 soil loss, increase nutrient recycling and retention, and increase water holding capacity for only the cost of cover crop seed. These benefits make our farm more sustainable by increasing cash flow potential and reducing fertilizer dollars lost, along with making our soils more productive and resilient.

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, the local extension agents offered to help calibrate the machine, FarmShow Magazine featured our interseeder in their February 2020 edition, and the two local conservation districts have expressed interest in a field day on our trial acres. Also, NRCS personnel are familiar with the machine and express a need for timely cover crop planting in this area.

The Kreger Farms developed interseeder was very cheap and simple to make. 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.

The impact of being field specific, inexpensive, maximizing a farm’s nutrient recycling, soil conservation, soil resiliency, and a high clearance machine all contribute to increased soil productivity, farm cash flow, and an accessible machine.


Click linked name(s) to expand
  • Casey Guindon


Materials and methods:

We plan to conduct this research experiment in the Morris and Nauvoo, PA areas. The Kreger Farms designed interseeder will plant the cover crop seed. Zach Kreger (farm manager) will be the driver and oversee seed mixing. Cover crop seed will come from the Local Seeds Facility in Jersey Shore PA. Kreger Farms has their own seed mixing equipment and scales.

Planting cover crop seed will be done as follows:

V6 Interseedings                                                                                                                                            

  1. 5 lb/acre Radish will be planted V6 with 50 lb/acre Black Oats planted at silking in corn silage. It is our experience that black oats are successful when planted August to September.
  2. 100 lb/acre Cereal rye and 5 lb/acre radish in corn grain and corn silage.
  3. 25 lb/acre Annual ryegrass and 5 lb/acre radish in corn grain and corn silage.
  4. 100 lb/acre Cereal rye, 5 lb/acre radish and 4 lb/acre crimson clover in corn silage.

V12 Interseedings                                                                                                                                          

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

Silking Interseedings                                                                                                                                                    

  1. 5 lb/acre Radish and 50 lb/acre black oats planted at the same time in corn silage.
  2. 100 lb/acre Cereal rye and 5 lb/acre radish in corn silage and corn grain.

Interseeded acres will total 150-170 depending on corn planting conditions and final crop rotation decisions.

Weekly or bi-weekly biomass and percent cover readings taken by a Kreger Farms employee. The determination as to weekly verses bi-weekly will be if there has been measurable plant growth, as determined by a ruler. The employee will take pictures to document percent cover. Biomass will be sampled by cutting plant matter in a one square foot area in two representative locations per acre. It will be dried using a koster tester and weighed using a scale.

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. Kreger Farms has access to a commercial scale. Also, we have calibrated our forage wagons so we know how many tons they hold. For measuring grain corn, Kreger Farms has a moisture tester and a scale. The yield data will be statistically analyzed with a t-test.



Research results and discussion:

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

Participation Summary
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.