King Faisal University

Water Studies Center

Modeling Nutrient Availability in Salt Marsh Soil
Adel M. Elprince and Yousef Y. Al-Dakheel
Water Studies Center, King Faisal University, Al-Hassa, Saudi Arabia

Assessment of the availability of essential elements for plant growth is one of the most urgent nutritional problems in the management of salt marsh ecosystems. We approximated the soil solution in salt marshes by a standard seawater composition and a simulated model for dissolved organic carbon. Concentration of complex species of nutrients in salt marshes and a typical nutrient solution (Hoagland) were computed by simultaneous solution of the appropriate mass law and mole balance equations. Principal complex species of plant nutrients in salt marshes were: N(N2 , NO3-); P(HPO42-, MgPO4-); K(K+); Mg(Mg2+); Ca(Ca2+); S(SO42-, NaSO4-); B(H3BO3, B(OH)4-); Mo(MoO42-); Cl(Cl-); Mn(Mn2+, MnCl+); Fe(Fe(OH)2+, Fe Citrs); Zn(ZnOH+, Zn2+, ZnCO3, Zn Glyc); Cu(Cu Citrs). We computed the concentration of the available form of nutrients in salt marsh soil relative to Hoagland’s nutrient solution. Based on this ratio, plant nutrients in salt marshes were classified into four groups: osmotic adjustment group (Cl), potentially toxic group (Mg, B, S), potentially sufficient group (Ca, K, Mo), and potentially deficient group (Fe, Cu, Mn, P, Zn, N). Effects of pH on nutrient activities and the buffering of Fe, Cu, Mn, and Zn in salt marshes by EDTA were investigated and discussed. .