Effects of Natural Zeolite to Reduce Salt Stress in Kentucky bluegrass (Poa pratensis)
Authors: Marzieh Negahban, Sajedeh Saeedfar, Darioush Ramezan, Moazzam Hassanpour Asil
Number of views: 469
Salinity is one of the most important factors limiting growth and development in cultivated species. Kentucky bluegrass was grown in boxes filled with sand (100%), 95% sand: 5% zeolite, 90% sand: 10 % zeolite and 85% sand 15% zeolite (V/V). Poa pratensis plants were irrigated with 0.24, 3.4 and 6.4 dS.m-1 salt water daily for 6 months in greenhouse condition to study the effect of different levels of zeolite on turf quality (TQ) and some physiological growth factors, salt deposition, sodium absorption ratio (SAR) and ion composition in leachate under different levels of salinity. Saline water reduced (PR), transpiration, (SC), (ME), (WUE), maximum assimilation rate (Amax), carboxylation efficiency (g, m) and net assimilation rate (A360) compared to control. Amendment of sand with zeolite increased TQ, PR, transpiration, SC, ME, WUE, (Amax), (g, m) and (A360) during both the 2nd & 3rd months at both salinity levels. Highest effect obtained in highest percent of zeolite. The beneficial effects of zeolite on turf quality and other parameters diminished 3 months after treatments. Amendment of sand with zeolite reduced leaching of Na and K but, increased leaching of Ca and Mg. Using zeolite in medium increased SAR value compared to control. Results indicate that amending with zeolite may buffer soil solution Na concentration in short-term. In the long-term, however, a substantial amount of Na may be retained concurrent with Ca & Mg exchange, thereby increasing sodicity & salinity problems.