Potassium fixation in san joaquin valley soils derived from granitic and nongranitic alluvium

摘要: Potassium fixation influences the effectiveness of fertilization in soil-plant systems. A rapid method for measuring K could help clarify relationships with other soil properties, especially mineralogy. Our objectives were to compare some existing measurement techniques and availability, develop an alternative test, evaluate utility texture parent material predicting soils derived from granitic Sierra Nevada (SN) nongranitic Coast Range (CR) alluvium. pools estimated by 1 mol L -1 NH 4 OAc sodium tetraphenylboron (TPB) extractions. 1-h correlated well (R 2 = 0.95, P= 0.001) a 7-d procedure, so was used subsequent work. The SN fixed up 740 mg kg ; CR soilsfixed 263 . There no significant relationship between clay or silt content either material. TPB test had stronger correlation OAc-extractable 0.77, P than 0.49, 0.001). Plant-available nonexchangeable (PANK minus OAc) did not correlate potential pooled data all pedons < 0.11), negative 0.97 0.99, 0.01) individual pedons. PANK probably represents that has already been satisfies capacity. is reliable, potential. Together, tests be useful identifying soils, thereby reducing