Effects of soil moisture on soil solution chemistry,biomass production,and shoot nutrients in two native grasses on a calcareous soil

Abstract

Two native grasses, Festuca ovina of dry and Agrostis stolonifera mainly of moist habitats of calcareous grasslands, were studied in an experiment with the objective of elucidating the effect of soil moisture level on soil solution chemistry, biomass production and shoot mineral nutrients. Eight levels of moisture, corresponding to 30–100% of the water‐holding capacity (WHC) of the soil, were tested. High correlation coefficients with soil moisture were observed for magnesium (Mg), phosphorus (P), and HCO₃ in soil solution. Amounts of calcium (Ca), Mg, and iron (Fe) in soil solution were lowest in the intermediate soil moisture range (60–70%). Shoot production, relative to maximum, was higher at low moisture levels for F. ovina than for A. stolonifera. Differences of P, Fe, and potassium (K) concentrations in shoots and maximum relative shoot production between the two species, are consistent with their field distributions as related to soil moisture. Lower soil moisture on calcareous soil is more favorable for F. ovina than for A. stolonifera. Variation in soil moisture regimes may greatly influence amounts of mineral nutrients in soil solution and uptake by plants and might even be a prerequisite for adequate acquisition of mineral nutrients and growth of plants on limestone soils.