Spatial and temporal variation of soil, climate, plants and irrigation requirements are challenges for modern agriculture and complex turfgrass sites. Precision agriculture (PA) evolved to improve site-specific management based on obtaining site-specific information. The focus of this concept paper is on the emerging area of precision turfgrass management (PTM) with attention given to: (a) comparing the concepts of PTM and PA in terms of driving forces and challenges that must be addressed for PTM to progress in science and practice and (b) discussion of specific field mapping applications (purposes) for different turfgrass situations such as golf courses, sod production fields and sports fields. The field applications relate to site-specific management of irrigation, salinity, fertilizer application and cultivation. To illustrate the potential for PTM, different approaches that may be necessary for PTM compared to PA are discussed. The initial factor that hindered the adoption of PTM has been the lack of mobile sensor platforms that can determine both key soil and plant properties for turfgrass situations. This paper concentrates on PTM field applications that involve mapping of both soil and plant attributes, in contrast to only optical sensing mapping.

Site‐specific management units (SSMUs), similar in soil, plant, and irrigation requirements, are foundational to efficient management in precision agriculture. This concept is applied to management of complex turfgrass sites to improve irrigation practices. An experimental mobile unit mapped two golf fairways' turfgrass (Paspalum vaginatum SW.; ‘Salam’) in Naples, FL in summer 2006 on a 2.5 m grid for volumetric water content (VWC) by time‐domain reflectrometry at field capacity and normalized difference vegetative index (NDVI). Objectives were to determine suitability of the GPS‐enabled mapping device and to develop protocols for defining and characterizing SSMUs by geographic information system (GIS) methods. Semivariogram analysis revealed that the mapping grid of 2.5 m was within the lowest observed range of 11.7 m for geospatial dependence for either VWC or NDVI. SSMU delineation was based on stable landscape traits of VWC at field capacity and topographic factors; with NDVI data as secondary. Descriptive and geostatistical means to best characterize SSMUs are presented. Use of field capacity VWC based distribution uniformity (DU) parameters is discussed for efficient irrigation scheduling applications within SSMUs.

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Spatial salinity mapping with a mobile sensor platform allowing GPS‐labeled data on turfgrass areas would facilitate site‐specific leaching programs for salinity management. A salinity monitoring device (SMD) based on 4‐Wenner array electrical resistivity (ER) electrode configuration was developed for turfgrass sites and tested on three soils at Griffin, GA and a golf course fairway in Naples, FL on two dates where the fairway received saline irrigation water. Using directed soil sampling, the SMD resulted in soil apparent soil electrical conductivity (ECa) vs. laboratory saturated paste extract electrical conductivity (ECe) linear relationships with r2 of 0.59 to 0.87 (p < 0.0002) for 0 to 10 cm and 0 to 20 cm zones at Griffin, GA. For two mapping events varying two‐ to threefold in salinity levels at the golf course fairway, the ECa vs. ECe linear regressions exhibited similar slopes, different intercepts (due to two to threefold difference in background salinity), and r2 of 0.53 to 0.58 (p < 0.002). On another fairway, a detailed spatial salinity map using geographic information systems (GIS) methods was developed using a sampling grid of 2 by 3 m, which was well within the 19 m range determined for spatial autocorrelation of the data. Our data suggest the empirical methods developed for agricultural soils for relating ECa to ECe and for determining average ECa of discrete subsurface zones may differ under turfgrass conditions due to stratification of the surface organic matter layer influencing water holding capacity, soluble salt retention, and averaging ECa within a subsurface zone.