Water conservation potential of modified turf grass irrigation in urban parks of Phoenix, Arizona

Abstract

Large amounts of water are consumed by urban parks in arid regions such that efficient irrigation practices are needed. In Phoenix, Arizona, extensive turf grass areas are supported using flood or sprinkler irrigation that also require fertilizers. Residential green waste compost has the potential to serve an alternative fertilizer if its higher costs can be offset through water conservation. In this study, we conducted an ecohydrological monitoring and modelling effort for a compost experiment in two urban parks with either flood or sprinkler irrigation. Soil moisture, evapotranspiration and turf greenness data along with a soil water balance model were used to determine if compost treated plots were different from control plots in each park. After building confidence in the model through comparisons to data, we created long‐term scenarios to explore differences between flood and sprinkler irrigation practices and analyse the effect of changes in irrigation scheduling. Multiple lines of evidence indicated that green waste compost applications did not appreciably change soil moisture or vegetation conditions in either urban park. Major differences, however, were noted between the two irrigation practices in terms of the seasonality of the soil water balance, plant water stress and the sensitivity to interannual fluctuations in precipitation. Model scenarios showed that significant irrigation reductions from 15% to 30% could be achieved, in particular with small changes in watering depths. As a result, irrigation management in urban parks can meet water conservation targets that potentially offset green waste compost costs while also benefitting the soil water balance through reductions in water losses.

Assessing Impacts of Environmental Perturbations on Urban Biogenic Carbon Exchange in the Chicago Region

“…Surprisingly, we do not observe an apparent increase in R eco over CMA, which contradicts some observation‐based studies (Decina et al., 2016; Kindler et al., 2022). One hypothesis suggests that excessive amounts of soil water will continuously enhance R eco , while the cooling effect will cease once the irrigation exceeds certain thresholds (Li & Wang, 2021a).…”

“…For example, irrigation, which helps urban plants growth and serves as a mitigation measure for extreme urban heat (Livesley et al., 2021), can lead to the environmental co‐benefits in cooling and carbon reduction (Li & Wang, 2021a) (Figure 1f). Conversely, over‐irrigation may cause unintended CO 2 release from soil respiration (Decina et al., 2016; Hundertmark et al., 2021; Kindler et al., 2022), offsetting CO 2 absorption from photosynthesis (Figure 1g). The lack of consensus indicates the large spatial variation of biogenic CO 2 efflux that different mechanisms could govern.…”

Assessing impacts of environmental perturbations on urban biogenic carbon exchange in the Chicago region

“…Surprisingly, we do not observe an apparent increase in R eco over CMA, which contradicts some observation-based studies (Decina et al, 2016;Kindler et al, 2022). One hypothesis suggests that excessive amounts of soil water will continuously enhance R eco , while the cooling effect will cease once the irrigation exceeds certain thresholds (Li and Wang, 2021).…”

“…1f). Conversely, over-irrigation may cause unintended CO 2 release from soil respiration (Decina et al, 2016;Hundertmark et al, 2021;Kindler et al, 2022), offsetting CO 2 absorption from photosynthesis (Fig. 1g).…”

Detecting Streamflow in Dryland Rivers Using CubeSats

“…For instance, Planet Labs uses a constellation of CubeSats (i.e., a large fleet of small satellite units) to survey the entire Earth at a high spatial resolution (∼3 m) and an unprecedented daily frequency since 2017. The resulting PlanetScope imagery have been used in a number of scientific applications in the natural and built environments (Houborg & McCabe, 2016;Kindler et al, 2022;Shugar et al, 2021;Vivoni et al, 2020), including for the detection of permanent and ephemeral water bodies and their changes over time (Cooley et al, 2017(Cooley et al, , 2019Mishra et al, 2020;Panda et al, 2020).…”