Effects of Salinity Applied to Seashore Paspalum On Three Simulated Athletic Field Situations: II. Plant and Soil Fertility Responses.

Understanding plant responses over time and by soil type when exposed to increasing salinity is important with the increases use of saline irrigation water.  Sea salt was applied by drop spreader and irrigated into the canopy of ‘SeaIsle 1’ seashore paspalum (Paspalum vaginatum) at 0, 66, and 132 kg/100 m²  under three simulated athletic field soil conditions with each soil as a separate study: a) sand profile -- sand meeting the USGA Green Section specifications for golf green construction to a depth of 30 cm, b) sand cap -- 10 cm sand cap over an Appling sandy clay loam using the same sand as in the sand profile, and c) native soil -- Appling sandy clay loam. Each soil was at field capacity at the initiation of the first dry-down on 13 Oct 2008 and when salt was reapplied at the same rates on 21 Oct 2008 for the second dry-down.  No irrigation was applied for either dry-down (13-21 Oct; 21-27 Oct) but 2.7 cm rain occurred on 17 Oct and 3.0 cm 24 Oct. Soil salinity was determined by two devices based on 4-wenner array method and each was calibrated to saturated paste extract (ECe).  Plant response was determined by NDVI (normalized difference vegetative index) and visual evaluations. Plant responses versus soil salinity for the three soil types and during dry-down and after leaching events will be discussed.