Sufficiency Level of Available Nutrient (SLAN) and Minimum Levels for Sustainable Nutrition (MLSN) are two of the philosophies used for soil test interpretation in turfgrass management. A study was conducted from 2019 – 2020 to compare the effects of SLAN and MLSN nutrient recommendations on a ‘Penn A-4’ creeping bentgrass green (Agrostis palustris Huds.) and on a mix stand of annual bluegrass (Poa annua) and ‘Penncross’ creeping bentgrass green grown on United States Golf Association specification rootzone. This study was a split plot with three factors and three replications. The whole plot included three levels: MLSN, SLAN and nitrogen (N) fertilized control treatment. The subplot included two levels: trafficked and non-trafficked. Soil samples were collected in spring and autumn to a depth of 15 cm. Turfgrass color, quality, and NDVI were measured monthly. In 2019, nutrient recommendation rate for MLSN was 73 kg N, 37 kg P and 60 kg K ha-1; SLAN was 73 kg N, 56 kg P and 222 kg K ha-1; and N-fertilized control was 73.2 kg N ha-1. There were no differences among treatments for NDVI, color and quality but the SLAN philosophy had the highest soil P and K levels in autumn of 2019. In 2020, nutrient recommendation rate for MLSN was 73 kg N, 38 kg P and 67 kg K ha-1; SLAN was 73 kg N, 31 kg P and 216 kg K ha-1; and N-fertilized control was 73 kg N ha-1. Both philosophies exhibited higher quality and healthier color compared to N-fertilized control. SLAN philosophy had the highest soil P level but there were no differences in soil K levels between the two philosophies in autumn of 2020.
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