Improving Ground and Surface Water Quality by Reducing Commerical Fertilizer Applications to Land Receiving Livestock Manures

Final Report for FNC95-125

Project Type: Farmer/Rancher
Funds awarded in 1995: $4,644.00
Projected End Date: 12/31/1997
Region: North Central
State: Michigan
Project Coordinator:
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Project Information


My wife Mary and I own and operate a dairy operation along with our three children. We milk 45 registered Holsteins and raise heifers which usually number about 35. 120 acres are owned with an additional 20 rented. We have been farming for 19 years.

Minimum tillage describes the way we work most of our ground. The last two years I have used no till when rotating from hay into corn. I continue to use the chisel plow as my primary tillage tool, using it to incorporate the manure that is applied to the crop land.

The crops grown are typically 65 acres of corn of which 25 acres are chopped for silage and the remainder shelled and dried in our home grain bin. 50 acres of alfalfa hay are raised for livestock feed, most of which is chopped and stored as haylage in upright stave silos. A field is usually in hay for 5 or 6 years and then rotated into corn.

The dairy herd is housed in a typical tie stall barn. The heifers are housed in a free stall facility. No grazing is done by the milking herd. The older heifers and dry cows do have access to some pasture which is divided into four paddocks.

All of our manure is handled as a liquid. The manure form the tie stall barn is moved to an earthen storage via a piston pump. The manure from the heifer barn is scraped from the alleys to the piston pump where it is moved to the earthen storage. The manure pit has the capacity for 12 months storage. All of the manure is applied in the spring to corn ground just before tillage.

About eight years ago I obtained some Michigan State University (MSU) extension bulletins that described how to calculate credits for nitrogen (N), phosphorus (P), and potassium (K) from the manure. I began testing my manure for the nutrients it contained. I gradually began to experiment with reducing commercial fertilizer applications and checking yields. Fertilizer dealers kept telling me that I needed to use a phosphorus corn starter which put some doubt in my mind if I was doing the right thing. I researched more university studies that gave me confidence in continuing on farm testing.

The last five years I have developed and used what I call precision nutrient management. That is described in the following nine steps.
1) Set realistic yield goals
2) Test the soil
3) Determine crop fertilizer recommendations
4) Test the manure
5) Record manure applications
6) Calculate current nutrient applications form manure
7) Calculate residual nitrogen credits
8) Calculate additional commercial fertilizer requirements
9) Evaluate crop growth and yields

There has been a real resistance from farmers in our area to step out side the traditional way of fertilizing their crops. This traditional way has been to apply full rates of nitrogen to the corn crop and to always use a phosphorous based corn starter regardless of the manure that was applied.

This led me to consider applying for this SARE grant. I could then share the results with area farmers and have an impact on the management of manure and fertilizer.

The overall goal of this project was to demonstrate that a farmer could reduce the use of commercial fertilizers when animal manure was applied to the crop land.

If a farmer would accept this change in management, several things could be accomplished.

The threat to surface water quality form the build up of phosphorus levels in the soil would be diminished. The threat to drinking water from the build up of harmful nitrate levels would be lessened. Form the farmer’s perspective; the greatest impact would be greater profits.

More specifically, I hoped to demonstrate that a farmer can indeed calculate the N, P, and K credits form manure applied, and use this information to reduce fertilizer inputs without impacting yields.

Planning and Conducting Research
This grant was used to establish crop (corn) fertility plots on our farm as well as on several other farms in the county.
- Phosphorus trials as well as nitrogen trials were conducted
- Fields were selected that had received manure
- It was desired that the field would be uniform in texture or soil type
- The following steps were completed in setting up the trials

a. Yield goals were established. This was based on previous crop yield history. Yield goals should be attainable in 3 out f 5 years
b. Soil tests were obtained
c. Crop fertilizer recommendations were determined using ‘Tri-state’ university (Michigan, Ohio, Indiana) recommendations
d. The manure was tested for the following nutrients:
i. Total nitrogen
ii. Ammonium nitrogen
iii. P2O5
iv. K2O

e. Manure applications were recorded including amount of manure applied and the days to incorporation.
f. Nutrients available to the crop from the applied manure were calculated
g. Residual nitrogen credits from previous year’s manure application were calculated
h. Additional commercial fertilizer recommendations were calculated
i. The phosphorus tests were conducted using either 0 lbs. or P2O5 or low rate of the same to determine the effectiveness of the phosphorus in enhancing yields.
j. Nitrogen plots were set up using several N rates to determine the effectiveness of calculating nitrogen credits.
k. Test plots were evaluated throughout the year using the following techniques
i. Soil nitrate test – taken in early June, used by some to determine how much more N if any is recommended to be applied
ii. Leaf tissue analysis – determines nutrient levels in the plant at silking time
iii. End of the season stalk nitrate test – used to evaluate nitrogen management efficiency. Stalk samples taken one to three weeds after black layer formation
iv. Yield checks – all harvested grain was electronically weighed and yields calculated.

The following people assisted with the project.
- Ed Hanenburg River Ridge Farms – provided acreage for conducting a test plot 1995
- Rick & Jamie Harley Sietsema Farms – provided acreage for test plot in 1995
- Bob & Don Hassevoort – provided acreage for test plot in 1995
- Arden Eadie E-D Farms – provided acreage for test plot in 1996
- Ira Krupp MSU Ottawa County Extension – helped with all aspects of this project from beginning to end.
- Paul Wylie MSU Extension Crops Specialist – helped with the outreach program presenting part of the “ten steps”
- Dr. Dale Mutch district MSU Extension Agent – helped explain the roll of cover crops in the outreach program “ten steps”
- Dr. Jim Kells professor of crops and sciences at MSU
- Ottawa County MSU Extension Secretaries – several of the office secretaries helped putting the data together, making graphs and typing for the tabloid that was published.

Results – 1995
All of the test plot information and results for 1995 are presented in the paper titled, “Ottawa County MSU Extension Nutrient Management Project” I will not show the data again in this part of the report. Please refer to the paper included with this report.

I will make some comments regarding the results. In our phosphorus starter demonstrations, the results were as I expected. Where ever the soil tests showed that the phosphorus levels were adequate as determined by “Tri State” fertilizer recommendations, we did not see a yield increase when phosphorus was banned in the row. The farmers that participated in these tests were using a phosphorus containing starter prior to these tests. They have all now gone to using nitrogen only at planting time banded by the row.

The nitrogen starter demonstration also confirmed “Tri-State’s” recommendation concerning the need for nitrogen banded by the row at planting time except when anhydrous ammonia is applied preplant.

One very important finding surfaced throughout these tests. This was that even when sufficient nitrogen was applied in the manure to meet the yield goal, as calculated in the credits, there was still a yield increase when nitrogen was banded by the row at planting time. I believe this phenomenon occurs because in the spring when the corn plant is in its early stage of growth, the ground is cold and then manure has not yet begun to mineralize. During this time the corn is suffering from nitrogen deficiency which has an impact on yield even though later in the corn’s life, tests demonstrated that there was sufficient or even excess nitrogen available.

Learning from this, I believe it would be better to plan on applying 30 to 40 lbs of nitrogen at planting time and then calculate how much more manure would be needed to meet the nitrogen requirements of the growing crop.

Results – 1996
1996 was a drought year for many farmers in the area. I completed the preliminary work to set up test plots on four farms besides my own. Three of these test plots were harvested for corn silage to meet the feed needs of the farmers. Only the test plot of Arden Eadie was harvested for grain. The field information and results from my farm and Arden’s will follow.

Field C on Dykevale farm 1996
This test varied the rate of nitrogen that was bended by the row at planting time.

Field information: C
Soil type, sandy loam
Previous crop and yield , corn 120 bu/acre
Nitrogen credits from other years, 44 lbs
Manure application, 6400 gallons liquid dairy manure, incorp. In 6 hrs.
Solid, 6.8%
Total N, 28.6 lbs/1000 gal
P2O5, 13.8 lbs/1000 gal
K2O, 27.9 lbs/1000 gal
Ammonia –N, 15.1 lbs/1000 gal

Soil test information
pH , 6.7
Bray P1, 150 lbs/acre
Exch. K, 280 lbs/acre
Exch. CA, 2300 lbs/acre
Exch. Mg, 210 lbs/acre
CEC , 6.9 me/100g
Organic matter, 3.1%

Crop information
Hybrid variety, Pioneer 3751
Yield Goal, 120 Bu/acre
Seeding rate, 27700 kernels/acre
Tillage, chisel/disc/plant
Planting date, May 31, 1996
Row width, 30 inches

Fertilizer requirement calculations
N, P2O5, K2O
Tri-state fertilizer recommendations, 140, 0, 20
Total manure nutrient credits 1996, 79, 79, 168
Residual manure nitrogen credit, 44
Additional fertilizer needed, 21, 0, 0

The calculated N requirement for this plot was 21 lbs.
Four different rates of N were applied at planting time, banded by the row.
They were 0lbs nitrogen
36 lbs nitrogen
50 lbs nitrogen
66 lbs nitrogen

Test results: Field C 1996
N starter (Lbs/acre), 0 , 36, 50, 66
Calculated N Requirement (Lbs/acre), 21, 21, 21, 21
Soil nitrate test N recommendation (Lbs/acre), 40, 40, 40, 40
Leaf nitrate %, 3.3, 3.5, 3.4, 3.4
Stalk nitrate ppm NO3-N, 1740, 1840, 2760, 3230
Yield Bu/acre, 38, 50, 54, 51

Comments on field C:
The soil nitrate test translated to a nitrogen recommendation of 40 lbs. This is more than the calculated need of 21 lbs. This result is consistent with other tests that have been completed, comparing the soil nitrate test with the calculated requirement. This can be explained by the following. The soil nitrate test measures only the nitrate-N present at the time the test is taken which in Michigan is in early June. The manure that was applied will continue to mineralize throughout the growing season making more nitrogen available than what was measured by the soil nitrate test.

It must be noted here that form the time that the corn was 8 inches tall through harvest, it was very easy to pick out the rows that received no N at planting time. These rows remained shorter and a paler green throughout the season.

The sufficiency range for N on the leaf tissue analysis is from 2.7% to 3.5% N. It can be seen in the above chart that by silking time there was sufficient N under all the treatments.

The stalk nitrate test is a measure of the efficiency of nitrogen management. The optimal range is from 700-2000 ppm NO3-N. At the fertilizer rate of 0 & 36 lbs/acre the nitrate test results fall into the optimal range. The two higher rates demonstrate that nitrogen was applied in excess of what was needed by the plant.

The yields from this test plot tell the story. At 0 lbs N applied, the yield was down substantially from the other N rates. The yields at the other three rates are essentially the same. There is demonstrated little advantage in applying nitrogen at rates above what was the calculated need.

These results were expected and further reinforces the premise that farmers can calculate the credits from manure and reduce the inputs of commercial fertilizer without impacting yields.

Field 3 E-D farms 1996
This test varied the rate of nitrogen that was banded by the row at planting time.

General information: 3
Soil type, Sandy loam
Previous crop and yield, corn 135 bu/acre
Tillage, no till
Manure application 96, 5000 gal liquid dairy – not incorporated
95, 7000 gal liquid dairy
94, 4000 gal liquid dairy
93, 4000 gal liquid dairy

Manure analysis:
Total nitrogen, 43 lbs/1000 gal
P2O5, 18 lbs/gal
K2O, 31 lbs/gal
Ammonia-N, 19 lbs/gal

Soil test information:
pH, 6.9
Bray P1, 76 lbs/acre
Exch. K, 234 lbs/acre
Exch. Ca, 2000 lbs/acre
Exch. Mg, 520 lbs/acre
CEC, 7.6 meq/1000g
Organic matter, 2.7%

Crop information:
Hybrid, Pioneer 3525
Yield goal, 160 bu/acre
Seeding rate, 28,000 kernels/acre
Planting rate, May 14, 1996
Row width, 30 inches

Fertilizer requirement calculations
N, P2O5, K2O
Tri-state fertilizer recommendation, 190, 0, 0
Total manure nutrients credits 1996, 35, 79, 130
Residual manure nitrogen credits, 42
Additional fertilizer nutrients needed, 113, 0, 0

Nitrogen fertilizer rates banded by the row: 60 lbs nitrogen
120 lbs nitrogen
170 lbs nitrogen
170 lbs nitrogen was this farmer’s usual rate of fertilizer application.

Test results field 3
N starter (lbs/acre), 60, 120, 170
Calculated N Recommendation (lbs/acre), 113, 113, 113
Pre-sidedress nitrate test recommendation (lbs/acre), 150, 150, 150
Leaf nitrate %, 3.5, 3.6, 3.7
Stalk nitrate ppm NO3-N, 3300, 3760, 3650
Yield bu/acre, 104, 109, 107
Moisture %, 33.4, 32.6, 32.2

Comments on field 3:
The test plot results shown above demonstrated that there was little difference in yield for the three starter treatments. The yields obtained by this farmer on this field were much less than his yield goal. This was however a drought year which would explain the depressed yields. Had this been a normal rainfall year we might have expected to see a yield response from the increase in nitrogen rates. Looking back we could say that if our yield goal had been set at 110 bu/acre then our calculated N recommendation would have been around 60 lbs/acre of nitrogen. Based on the yields obtained that would have been the optimal rate.

The soil nitrate test again under estimated the amount of nitrogen that was available to the growing crop. The soil nitrated test recommendation was 150 lbs/acre compared to our calculated recommendation of 113 lbs/acre.

The stalk nitrate test exhibited excess nitrogen in the corn plant at all three nitrogen rates. The moisture variation between treatments was not significant.

Income over fertilizer costs for field C
60 lbs/acre N rate, $274.40/acre
120 lbs/acre N rate, $271.60/acre
170 lbs/acre N rate, $252.00/acre
Nitrogen @ $.28/lb
Corn @ $2.80/bu

This comparison of fertilizer rates with the value of grain harvested demonstrates that even though higher yields were obtained with the higher rates of fertilizer, the profits decreased as the rate of nitrogen increased. The highest income per acre this year was achieved at the lowest rate of fertilizer. The results another year with more favorable growing conditions might be different.

1997 test plot results
Field information: Field E
Soil type, loam
Previous crop and yield, corn 135 bu/acre
Tillage, chisel-plant
Residual N credits, 70 lbs/acre
Manure application east, 8000 gal/acre incorporated in 5 days
Manure application west, 8000 gal/acre incorporated in 1 day

Manure analysis:
Solids, 7.6%
Total N, 26.2 lbs/1000 gal
NH4-N, 14.2 lbs/1000 gal
P2O5, 13.2 lbs/1000 gal
K2O, 27.5 lbs/1000 gal

Soil test:
pH, 6.9
Bray P1, 56 lbs/acre
Exch. K, 160 lbs/acre
Exch. Ca, 900 lbs/acre
Exch. Mg, 220 lbs/acre
CEC, 6.8 meq/mg
Organic Matter, 3.6%

Crop information:
Hybrid Variety, Pioneer 35N05
Yield Goal, 140 bu/acre
Seeding Rate, 27,700 kernels/acre
Planting date, May 14, 1997
Row width, 30 inches

Nitrogen requirement calculations – East:
MSU nitrogen recommendations, 160 lbs/acre
Residual N credits, -50 lbs/acre
N from manure applications, -52 lbs/acre
Additional N required, 58 lbs/acre

Nitrogen requirement calculations –West:
MSU nitrogen recommendations, 160 lbs/acre
Residual N credits, -50 lbs/acre
N from manure applications, -119 lbs/acre
Additional N required, 0 lbs/acre

The calculated n requirement for the east plot was 58 lbs
The calculated n requirement for the west plot was 0 lbs
The difference here was that the east plot’s manure was incorporated 5 days after application while the west plot’s manure was incorporated one day after application. It was calculated that over 59 lbs of N was lost from the east plot in the 5 days that the manure laid on the soil surface.

Two different rates of N were applied at planting time on the east plot.
Five different rates of N were applied at planting time on the west plot.

Test results: East this test was a side by side test
N starter, 48, 60
Calculated N requirement (lbs/acre), 58, 58
Soil nitrate N recommendation (lbs/acre), 0, 0
Stalk nitrate (ppm), 4960, 4510
Yield bu/acre, 131, 137

This plot came about as the result of rain delaying the incorporation of the manure. It serves a purpose though in that it shows the results of delayed incorporation. There is a dramatic difference in the calculated N recovered from the manure. The results show a good increase from the higher rate of N. I should have applied one more rate at about of 90 lbs of N. That would have better defined the optimal N rate.

Test results: West this plot was replicated four times randomly
N starter (lbs/acre), 0, 34, 40, 48, 60
Calculated N requirement, 0, 0, 0, 0, 0
Soil nitrate test recommendation (lbs/acre), 0, 0, 0, 0, 0
Stalk nitrate (ppm nitrate), 4780, 5090, 5110, 5770, 5240
Yield (bu/acre), 125, 137, 139, 135, 158

Some of the test results from this west plot are what I expected and some of the results I don’t have an explanation for.

First of all the calculated N requirement and the pre-sidedress results are the same. My previous experience has shown that the pre-sidedress recommendations usually under estimated the N available to the plant and therefore usually called for more N to be applied.

Secondly I would have expected a yield increase when the 34 lbs of N were applied even when the calculations didn’t call for it. This is consistent with previous test.

Thirdly the rather flat yield curve for the N rates of 34 lbs to 48 lbs is what I would have expected given that we usually see the yield increase for the first 30 lbs of N over the calculated requirement. Seldom do I see a yield increase when higher rates are applied I cannot explain the yield increase obtained at the 60 lbs rate other then to say that only two test strips were at the 60 lbs rate. More replications might have adjusted the results somewhat.

The end of season stalk nitrate tests revealed excessive nitrate levels at all rates of nitrogen starter. I don’t know why the results were so high. It is possible that the samples were not taken at the right time. The proper time is from one to three weeks after black layer formation in the corn kernel.

Participating in this grant program helped me to understand more about the proper way to do on farm research. It helped me to understand the need to keep detailed records and notes.

Having spread this work over three years helped me to understand the need for the test plot work to span several years. With the changeable weather and varying growing seasons it was evident to me that one cannot make management decisions based on one years test results.

I do not plan on making any changes to my farming operation because of the test plot work completed. This test plot work just further reinforced that what I have been doing has been a good sustainable practice. Nutrient management does work.

The real rewards of implementing a project like this is being able to share the information with others. I really enjoyed being able to talk to others about my test plot work.

The only disadvantage was that it took time away form my farming operation. If asked for more information, I would share all my results and show them how my results coincide with university recommendations. The tabloid that I published has been very helpful in this.

The impact, I think has been tremendous. Of the farmers that I worked with, all have changed their crop fertility practices. One farmer saved $20,000.00 the first year he began to giving credits for his manure. Another one heard about my work and asked me to help him with his crop fertility. He saved over $10,000.00 in fertilizer in one year. It is fun to work with a farmer and show him how he can increase his profitability, and then watch him smile!

The environment impact may be quantified by the pounds of fertilizer not used. If a farmer is reducing fertilizer inputs without impacting yields, that reduction in fertilizer use is putting less of a nutrient load on the environment.

The social impact is important too. In our part of Michigan, development pressure is being felt more and more. As more residential development takes place, the potential for conflict between home owners and farmers increase. Farming practices generate dust, noise, and odors. A farmer may be doing a conscientious job of handling the manure generated on the farm but many times the general public does not understand. It is very important that we in agriculture communicate to the general public that what we are doing on the farm is good sustainable agriculture practice. As the general public becomes aware of farmer’s efforts to be a good steward, it will have a positive effect on how the public views livestock operations and farming in general.

1) A news release was issued to area newspapers telling about the grant I received. This was published in threes of the area newspapers. Two of our local county agents talked on the radio about the grant and the work I would be doing. They requested that farmers contact me if they desired to work with me on a test plot. I also attended many of the local farm organizational meetings such as Farm Bureau, Pork Producers etc. telling the attendees of my grant work.
2) Project events and activities were widely published through the MSU Extension news letters and direct mailings to all of the county’s farmers. The local radio station’s farm report also mentioned the dates of our field days and meetings.
3) Project results for the first year were published in a tabloid format and mailed to all the farmers in Ottawa Co. Copies were also sent to every MSU Extension office in the state as well to several key people at MSU. In the winter of 1996 and 1997 I hosted an MSU Extension meeting that met in my local town of Coopersville. These two programs were all day affairs where I shared my program for “Ten Steps to Successful Nutrient Management”, nutrient management on my farm and the test plot results from the SARE grant work in 1995 and 1996. About forty area farmers attended each of these meetings.

In the fall of 1995 I hosted a test plot farm tour. This began at my farm and then visited two other test plot farms. This was attended by about ten farmers. I used posters that I had prepared to show the visitors what the test plots were about and what I was hoping to show by the results.

In March of 1998 I will again present my test plot results at a winter farm meeting hosted by Ottawa Co. MSU Extension. I am continuing to work with area farmers, helping them with nutrient management on their farms. This experience and creditability that I have gained has allowed me to begin a consulting business in nutrient management.


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.