Effect of different irrigation methods on salt distribution in soil profile in landscape areas

In this study, it was aimed to determine the salt distribution in the soil covered turfgrass which is widely used in recreation areas, under sprinkler and subsurface drip irrigation methods. The experiments were conducted in the land of Istanbul-Silivri Municipality Agricultural Production and Research Center (TÜRAM). In the study, two different turf varieties (K: cool season turf mixture; 30% Lolium perenne, 25% Festuca rubra rubra, 35% Festuca arundinacea, 10% Poa pratensis and B: warm season turf; Bermudagrass (Cynodon spp.)), 3 irrigation levels (S1,S2, S3). In the last year (2020) of a four-year research project, in order to determine the salt accumulation in the soil profile of KS1 and BS1 trials, in which no irrigation deficiency, disturbed soil samples were taken from different locations and depths (0-5 cm, 5-20 cm, 20-40 cm, 40-60 cm), twice on 31 August 2020 and 18 September 2020. In addition, soil samples were taken from two un irrigated points and four depths as witnesses. The salt content of each sample was measured with an EC meter from the saturation extract prepared in the laboratory, and the findings were given numerically and graphically. According to the results obtained, EC2/EC1 values, which express the ratio of the salt accumulation in the soil profile to the salt values at the witness points, were higher in the plots irrigated with the sprinkler method than that of subsurface drip irrigation method, and it was between 1.25-2.10 in the Bermudagrass plots, and between 1.02-3.00 in in the warm season turf plots. The fact that the aforementioned values are lower in warm climate grass can be attributed to the lower water requirement and lower evaporation losses of Bermuda grass due to high density and woody structure of turf. The EC2/EC1 values for Bermuda grass irrigated with the subdrip irrigation method were found between 0.95-1.20 and the EC3/EC1 values for the cool season turf mixture 1.36-2.09. Similarly, the low amount of irrigation water applied resulted in lower salt accumulation in Bermuda grass than in cool season turf. Salt accumulation just below the dripper was at a minimum level (0.43-0.63 dS/m). The absence of heavy salt accumulation between the dripper and lateral can be attributed to the wetting of the entire area. Again, the fact that salt does not accumulate on the soil surface, as seen in the classical drip irrigation method, can be attributed to the fact that the soil surface is not wet and consequently low evaporation and low capillarity.