Dairy Compost Utilization

McLennan County Demonstration

Contact Information:
Mr. Will Kiker
(254) 757-5180

Location: The Riesel Independent School District High School practice football field in McLennan County.

Objective: The primary objective of this demonstration was to evaluate the health, density, and appearance of the practice football field following a top dress application of dairy manure compost alone and dairy manure compost combined with fertilizer on a.

Introduction: The Riesel Independent School District’s high school practice football field was recently recrowned and in fair condition. School personnel wanted to maintain the field’s excellent health and further improve the density of the existing turf. Further, the School realized the poor condition of their actual playing field and were exploring options to improve its quality. Treatment and maintenance of the practice field was an excellent opportunity to evaluate some of these management techniques, which would ensure they could choose the most effective and cost efficient method to improve their playing field.

With assistance from Mr. Will Kiker, McLennan County Extension Agent, and Dr. Jim McAfee, Texas Cooperative Extension Turfgrass Specialist, Riesel ISD formulated a plan to conduct a demonstration on the practice field and implement specific management practices for their playing field. Because of the Dairy Manure Compost Incentive Program, Riesel ISD elected to apply dairy manure compost on the practice field as an alternative nutrient source. Application of the compost, mechanical aeration and efficient irrigation were all components of the practice field demonstration.

Procedure: The demonstration was initiated on June 22, 2005 when approximately 80 tons per acre of top-dress quality dairy manure compost was uniformly applied to the Riesel ISD practice football field. The compost was applied (Figure 1) utilizing a Turf Tiger® spreading unit (Figure 2) provided by the Agricultural Research Experiment Station in Stephenville. The compost spreader was purchased with grant funds provided by the Texas Commission on Environmental Quality through an US EPA Clean Water Act Section 319(h) Grant. Also in conjunction with the grant, Riesel ISD received a rebate of $5 per CY of compost purchased, which improved the economics of the demonstration and specifically, this management practice for the school.

The spreading unit was calibrated (Figure 3) prior to adding dairy manure compost to the field to ensure a uniform application. Subsequently, the field was mechanically aerated to partially incorporate the compost, enhance nutrient and water uptake and to reduce compaction.

Figure 1

Figure 1. Broadcast application of dairy manure compost on Riesel ISD practice football field.

Figure 2

Figure 2. Loading Turf Tiger® spreading unit with topdress quality dairy manure compost.

Figure 3

Figure 3. To calibrate the spreader, dairy manure compost is applied into collection unit and weighed as indicated above. By calculating distance of spreader and amount applied, the spreader can be accurately calibrated to ensure a uniform application rate across the field.

Irrigation was applied (Figure 4) for the first time 3 weeks after compost application. As the season progressed, school personnel wanted to evaluate the addition of inorganic nitrogen fertilizer as well. Therefore, an application of inorganic nitrogen was applied to the south end of the field at a rate of 1 lb nitrogen per 1,000 square feet approximately 4 weeks after the compost application.

Figure 4

Figure 4. Irrigation was applied for the first time approximately 3 weeks after compost application.

Supplemental applications of inorganic nitrogen are typically utilized because the ratio of nutrient concentrations in a compost product is rarely an exact fit for turfgrass needs. An application of compost that meets nitrogen requirements will often provide excess phosphorus. As a result, compost application rates should be determined based on turfgrass phosphorus requirements and supplemented with a phosphorus free inorganic fertilizer to complete turfgrass nitrogen and/or potassium requirements.

In addition to the demonstration conducted on the practice field, TCE personnel also worked with the School to implement alternative management techniques on the playing field. Realizing the field potentially needed complete reconstruction, the school opted to implement inexpensive management techniques for the current year in order to bring the field to proper playing condition for the upcoming season. Throughout the summer of 2005, the school mechanically aerated the playing field on a frequent basis and TCE conducted an irrigation audit in July to ensure irrigation applications were both effective and efficient. By implementing these inexpensive management practices, the school was able to better arrange funding for pending future activities such as recrowning and / or dairy compost applications. Further, the school was able to evaluate the effects of dairy manure compost on the practice field without investing additional funds in the playing field.

Results: A pre and post soil sample was collected from the practice field. The pre soil sample was collected in May 2005 and a follow-up soil sample was taken 6 months after demonstration installation. The post treatment soil sample was collected from both the North and the South ends of the football field. The North end as stated did not receive a supplemental rate of inorganic N, while the South end did receive the supplemental inorganic nitrogen application at a rate of 1 lb nitrogen per 1,000 square feet approximately 4 weeks after the compost application. All soil sample results are presented in Table 1.

Dairy manure compost was sampled prior to application in June 2005 and results for dairy manure compost characteristics are presented in Table 2.

Table 1. Laboratory analysis results of soil samples taken before (PRE) application of compost and 5 months after (POST) the application of compost.

----------- ppm ----------- umho/cm
PREWhole field 19 87 320 4381 186 28 240 7.8 291
POSTNorth 46 161 513 4827 251 50 402 7.9 465
South 55 169 567 5650 281 70 357 7.8 516

Table 2. Laboratory analysis results of top-dress quality dairy manure compost based on an oven dried sample (% and ppm) and based on an as received basis (pounds per wet ton).

---------- % ---------- ------ ppm ------ %
1.3600 0.3915 1.4216 13.2474 0.6471 0.5650 140 8,095 59.5 260.5 11.9
---------- lbs per wet ton of compost ----------
23.97 15.80 30.07 233.48 11.40 9.96 0.247 14.267 0.105 0.459 NA

The dairy manure compost application, aeration and efficient irrigation resulted in improved turfgrass density and uniformity on the practice field (Figure 5). These improvements were noted as the field grew greener in color and the turf even began outcompeting some of the unwanted grass species. The post soil sample results did exhihit elevated levels of P. While these results were not at an environmentally harmful level, it should be noted that school personnel should avoid any applications of P or organic type fertilizers for several years or until soil tests indicate a need for P.

By cooperating with TCE, Riesel ISD was able to evaluate various management techniques for the maintenance of their practice field and the recovery of their playing field in an economical manner. In addition, the School District was supporting a local industry and helping protect a neighboring natural water source.

Figure 5

Figure 5. Riesel ISD practice football field overview prior (left) to and 1 month after (right) top dress quality dairy manure compost was applied.

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