Ammonium and nitrate in the nitrogen economy of some conifers growing in Douglas-fir com-


Hydration of a commercial hydrophilic polyacrylamide gel in 20 meq Ca(NO 3)2/ liter was reduced to <10% of the maximum hydration in deionized water. Repeated soaking with deionized water to remove soluble salts restored hydration to ≈ 30% of maximum. Incorporating KNO3 at concentrations ranging from 5 to 40 meq·liter -1 with the Ca(NO3)2 in the hydration… (More)


2 Figures and Tables