[K fertility and K deficit index of aquic brown soil under different fertilization systems].
A 15-year fertilization experiment was conducted on an aquic brown soil to study the variations of its K fertility and the index of K deficit under different fertilization systems. The results indicated that no K application accelerated the depletion of soil K, representing a certain decrease of soil available and slow-release K. Applying K alone could not keep soil K in balance, still having a decrease of soil available and slow-release K. The application of recycled compost combined with appropriate amount of fertilizer K could compensate soil K expenditure to a certain degree, and keep the concentrations of soil available and slow-release K somewhat constant. The statistic analysis on the past years test results showed that the critical values of soil available K in corn- and soybean fields obtained by crossing method were all 73 mg x kg(-1).
Yu
Wan-Tai
WT
Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China. wtyu@iae.ac.cn
Jiang
Zi-Shao
ZS
Shen
Shan-Min
SM
Zhang
Lu
L
D000383:Agriculture / Q000379:methods; D018556:Crops, Agricultural / Q000254:growth & development*; D005308:Fertilizers; D011188:Potassium / Q000032:analysis*; D012987:Soil / Q000032:analysis*
D005308:Fertilizers; D012987:Soil; D011188:Potassium