The better extracting method and kinetic model for describing the release and rate of soil non exchangeable K were discussed with Elovich, Second order kinetic models by 0 50 mol· L -1 HNO 3, 0 01 mol·L -1 oxalic acid and H resin successive extraction under constant temperature and pot exhaustion of ryegrass.

The paper put forward a method to measure the commutative Ca、Mg、K and Na in the soil simultaneously by the extractive of ammonium acetate 1 mol/L.

Field and laboratory experiments were conducted to characterize the evolution characteristic of potassium (K) and its mechanism as affected by different climates, cropping systems, and long-term fertilization, and to investigate the effect of long-term fertilization on K fixation capacity using laboratory simulating methods and X-ray diffraction, and the nonexchangeable K release in 0.