SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: https://read.dmtmag.com/i/678624
www.stma.org June 2016 | SportsTurf 35 It is evident from these maps that there are large amounts of variability (i.e. differences) across this field for both soil moisture and catch can data. Detailed soil moisture and catch can patterns clearly indicate deficiencies in uniformity and efficiency down to individual irrigation heads. Several conclusions can be derived from examining these maps; however, we will only discuss a few. In general, similar distribution patterns exist between the two maps, except for a few areas around some of the irrigation heads. The northern part of the field appears to have the lowest soil moisture values, while the southern part of the field has the highest. Similar conclusions can be drawn from the map of catch can data. However, the northern part of the field appears to be receiving higher levels of water, although the soil moisture map does not reflect that it is infiltrating the soil. The contrasting results in the northern portion of the field indicate that although the area is receiving water, there is some other factor (i.e. soil compaction, localized dry spot, etc.) influencing infiltration into the soil. High soil moisture and catch can values in the southern portion of this field may be due to poor irrigation system design (the last row has an extra irrigation head). The dry area in the central part of the field is likely due to reduced efficiency of the heads in that area. Further analysis indicates a DU of 61% for soil moisture and a DU of 58% for catch can data. Therefore, this irrigation system is performing at just above poor. The correlation coefficient for the soil moisture and catch can data was 0.45. A positive value was expected, since typically the more irrigation water an area receives the high the soil moisture; however, the strength of the relationship was moderate. This further demonstrates that other factors may be influencing water infiltration. FIELD 2 (SAND CAPPED) The soil moisture and catch can distribution maps for Field 2 are shown in Figure 3. Unlike Field 1, there are no circular soil moisture or catch can distribution patterns around any of the irrigation heads in the map of Field 2. Low water holding capacity of the sandy soil may have impacted the soil moisture of Field 2, because less runoff and quicker water infiltration is typical for coarse textured soils. Examination of the catch can map reveals that the irrigation system is performing well and distributing water evenly. The design of this system appears to be sufficient, but comparison of the two maps shows conflicting distributions. Soil moisture is highest in the northern part of the field, specifically in the northeast corner. The catch can map, although somewhat uniform, depicts higher values in the center and southern portion of the field. This might lead one to believe that the slope of the field is responsible for the differences, which is partially correct. The field is crowned, but predominantly directed toward the northern half. Although there is no subsurface drainage within the field, there are drains Figure 1. Soil moisture and catch can sample locations (black dots) on Field 1 (sandy loam) and Field 2 (sand capped).