2009 Soil Fertility Comparison Study in Bermuda Grass Pastures
Conducted by:
Texas AgriLife Extension Service County Agents for:
Wood, Rains, Smith, Upshur, and Van Zandt Counties and Extension Forage Specialist in Overton
Summary:
Fertilizers have been proven to be an effective method to increase forage yields and nutrient value of warm season grasses. Today, there are numerous choices for producers to make when determining what soil fertility to use.
Objective:
The objective of this result demonstration was to compare the different fertilizers for total yield and nutrient value of bermuda grass pastures and the economics of each (lowest cost).
Materials and Methods:
Materials used for this experiment were as follows; Conventional Fertilizer I, Conventional Fertilizer II, Poultry Litter, Poultry Litter plus 50 units of Ammonium Nitrate, Poultry Litter plus 50 units of Urea, Task Force Liquid (11-8-5), Grasshopper (30-10-10), Parker Organic, Bjork Organic, and Control. The trial was a completely randomized block design replicated three times. Rate for the fertilizers are listed in Table I. The plots were 10 feet wide by 15 feet long. A one foot square was harvested from the plots, weighed and a laboratory analysis performed to determine protein, Acid Detergent Fiber (ADF) and Total Digestible Nutrients (TDN) twenty-eight (28) days after fertilizer application. The plots were harvested three times to simulate three hay cuttings per year. Fertilizer application was conducted one (1) week after each plot harvest.
Table I. Fertilizer and Rates Used in Study
| Fertilizer | 1st Harvest Rate | 2nd Harvest Rate | 3rd Harvest Rate |
| Conventional Fertilizer I (30-0-20) | 475 lbs/acre | 0 lbs/acre | 0 lbs/acre |
| Conventional Fertilizer II (30-20-20) for 1st and 2nd Harvest. 3rd harvest using 21-0-21 | 316 lbs/acre | 250 lbs/acre | 357 lbs/acre of 21-0-21 |
| Poultry Litter | 2 tons/acre | 0 tons/acre | 0 tons/acre |
| Poultry Litter Plus Urea (50 units of nitrogen) | 2 tons/acre poultry litter plus 109 lbs/acre of 46-0-0 | 109 lbs/acre of 46-0-0 | 109 lbs/acre of 46-0-0 |
| Poultry Litter Plus Ammonium Nitrate (50 units of nitrogen) | 2 tons/acre poultry litter plus 147 lbs/acre of 34-0-0 | 147 lbs/acre of 34-0-0 | 147 lbs/acre of 34-0-0 |
| Bjork Organic | Texas Tee 435.6 lbs/acre | Texas Tee 435.6 lbs/acre | Top Organic 435.6 lbs/acre |
| Parker Organic | 30 gallons/acre of product plus 20 gallons of water/acre | 30 gallons/acre of product plus 20 gallons of water/acre | 30 gallons/acre of product plus 20 gallons of water/acre |
| Task Force Liquid (11-8-5) | 3 quarts/acre | 3 quarts/acre | 3 quarts/acre |
| Grasshopper Foliar Liquid (30-10-10) | 12.5 lbs/acre | 12.5 lbs/acre | 12.5 lbs/acre |
| Control | 0 | 0 | 0 |
Results and Discussion:
A treatment by date interaction occurred for dry matter of forage produced. There was a significant increase in forage produced for each fertilizer treatment at the July harvest (treatment 3). This increase in forage was due to an increase in rainfall for the month of July (treatment 3). Treatments for May and June harvest were not significantly different for all treatments. July harvest was significantly different from May and June harvests (Table II). May was a very cool month with cool nighttime temperatures which slowed grass growth. June was extremely hot and dry. There was very little soil moisture to promote grass growth. July was very wet and had a significant increase in grass production. The first harvest (May) Conventional I, Poultry Litter plus Urea, Poultry Litter plus Ammonium Nitrate, Bjork Organic, Grasshopper Foliar Liquid (30-10-10), and Conventional II were significantly different than Poultry Litter, Parker Organic, Task Force Liquid 11-8-5 and Control at a (P<0.05 level). The second treatment (June), no treatments were significantly different (P<0.05 level) due to the high temperatures and no rainfall. The third treatment (July) Poultry Litter plus Urea, Poultry Litter plus Ammonium Nitrate, Parker Organic, Bjork Organic, Grasshopper Foliar Liquid (30-10-10) and Conventional II were significantly different (P<0.05) from Conventional I, Poultry Litter, Task Force 11-8-5, and Control.
Table II. Dry matter (lb/acre) of forage produced by treatment. Treatment by date interaction
(P < 0.0001; SE = 426.72)
| Fertilizer | May | June | July |
| Conventional(high) | 1673.65a,b,c | 625.28ac | 2221.18b,c |
| Poultry Liter | 247.33a,d | 442.31ac | 1882.61b,c |
| Poultry Liter + 50 units Urea | 1032.19a,c | 1096.40ac | 3600.83b,d |
| Poultry Liter + 50 units Ammonium Nitrate | 753.50a,c | 515.78ac | 4057.11b,d |
| Parker Organic | 317.92a,d | 494.17ac | 4642.48b,d |
| Bjork Organic | 1065.18a,c | 623.84ac | 5408.09b,d |
| Task Force Liquid (11-8-5) | 491.77a,d | 257.89ac | 1636.24b,c |
| Grasshopper Foliar Liquid (30-10-10) | 610.39a,c | 746.30ac | 3109.54b,d |
| Control | 513.38d | 400.52ac | 1498.80c |
| Conventional 95-0-65 | 763.59a,c | 825.54ac | 4098.46b,d |
Table III: Crude protein (%) of Coastal Bermudagrass. Treatment by date interaction
(P < 0.0001; SE = 1.74)
| Fertilizer | Date | ||
| May | June | July | |
| Conventional (high) | 21.73b,c | 12.10a,c | 14.40a,c |
| Poultry Liter | 14.80b,d | 9.43a,c | 9.77a,d |
| Poultry Liter + 50 units Urea | 22.03b,c | 15.30a,c | 16.23a,c |
| Poultry Liter + 50 units Ammonium Nitrate | 15.23a,d | 14.70a,c | 15.77a,c |
| Parker Organic | 16.87b,d | 16.17b,d | 13.57a,c |
| Bjork Organic | 21.0b,c | 13.47a,c | 16.57a,c |
| Task Force Liquid (11-8-5) | 13.9a,d | 9.30a,d | 11.37a,d |
| Grasshopper Foliar (30-10-10) | 17.4b,d | 11.23a,d | 11.10a,d |
| Control | 13.17b,d | 9.53a,d | 9.57a,d |
| Conventional 95-0-65 | 18.33b,c | 15.97a,c | 15.13a,c |
Table IV: Average Cost per application and Total Cost for Three Applications
| Fertilizers | Cost ($)/ Acre/Treatment | Total Cost |
| Conventional I | 1st Treatment =$114 | $114 |
| Conventional II | 3 Treatments | $110 |
| Poultry Litter | $70 | $70 |
| Poultry Litter Plus Urea (50 units of nitrogen) | 1st Treatment Poultry Litter plus Urea =$91.80 2nd Treatment Urea= $21.80 3rd Treatment Urea = $21.80 | $135.40 |
| Poultry Litter Plus Ammonium Nitrate (50 units of nitrogen) | 1st Treatment Poultry Litter plus Ammonium Nitrate = $94.99 2nd Treatment Ammonium Nitrate= $24.99 3nd Treatment Ammonium Nitrate= $24.99 | $144.97 |
| Bjork Organic | 1st Treatment Texas Tee= 435.6 lbs/acre=$231 2nd Treatment Texas Tee=435.6 lbs/acre= $231 3rd Treatment Top Org. = 435.6 lbs/acre =$182 | $644 |
| Parker Organic | $30 | $90 |
| Task Force Liquid (11-8-5) | $13.50 | $40.50 |
| Grasshopper Foliar Liquid (30-10-10) | $14.90 | $44.70 |
Table VII: Total Yield for all Three Harvest, Tons, Average Protein, and Number of 1000 Pound Bales Produced.
| Fertilizer | Total Yield Lbs/Acre (3 harvest) | Total Tons/Acre | Total Bales/acre(1000 lbs) | Average Protein | Cost/Ton |
| Conventional I | 4520.11 | 2.26 | 4.5 | 16.1 | $50.44 |
| Conventional II | 5687.59 | 2.84 | 5.7 | 16.5 | $38.85 |
| Poultry Litter | 2324.92 | 1.16 | 2.3 | 11.3 | $60.34 |
| Poultry Litter Plus Urea (50 units of nitrogen) | 5729.42 | 2.86 | 5.7 | 17.8 | $47.34 |
| Poultry Litter Plus Ammonium Nitrate (50 units of nitrogen) | 5326.39 | 2.66 | 5.3 | 15.2 | $54.50 |
| Bjork Organic | 7097.11 | 3.55 | 7.1 | 17 | $181.41 |
| Parker Organic | 5454.57 | 2.73 | 5.5 | 15.6 | $32.97 |
| Task Force Liquid (11-8-5) | 2385.90 | 1.20 | 2.4 | 11.5 | $33.75 |
| Grasshopper Liquid(30-10-10) | 4466.23 | 2.23 | 4.5 | 13.2 | $20.04 |
| Control | 2412.70 | 1.2 | 2.4 | 10.8 | $0.00 |
Conclusion:
Fertilizers have been proven as the key to improve forage production. This is the first of the three year result demonstration. In May, it was extremely cool and the forage did not have high enough nighttime temperatures for plant growth. June was extremely hot and dry, which slowed down plant growth. July and the first of August was extremely wet. Our plots had over nine (9) inches of rain during July and the first of August. Yields were very good during this period. Year one data looked very promising. This research project will continue for another two years.
Disclaimer Clause:
This is a modified and summarized version of a more detailed study conducted by Texas AgriLife Extension Service. The entire study is available upon request by contacting Grasshopper Fertilizer or Texas AgriLife. The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Texas AgriLife Extension Service is implied.
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