IPI International Potash Institute
IPI International Potash Institute

Table 7. Available P and K in soil as function of treatment and time

                                 
  Table 7. Available P and K in soil as function of treatment and time.1  
  Treatment NaHCO3 extractable P   NaHCO3 extractable K   CaCl2  
  0-20 cm   20-40 cm   0-20 cm   20-40 cm   0-20 cm  
  1963 1965 1987 1991 1994   1991   1991 1994   1991   1963  
    mg P kgsoil-1   mg K kg soil-1   mg K L-1  
  M0N0 - - 23 28 33   19   255 462   192   -  
  M0N3 - - 21 27 31   16   275 433   170   -  
  M2N0 - - 41 67 120   42   405 690   345   -  
  M2N3 - - 39 62 111   33   424 800   266   -  
  M1N3 - - 34 42 62   35   386 583   250   -  
  RN3 - - 26 32 41   24   266 540   213   -  
    Main factor means  
  N0 25 49 31 45 63   30   320 543   176   23  
  N1 24 44 33 38 69   24   300 621   244   25  
  N2 24 40 30 42 69   27   300 578   318   27  
  N3 21 40 30 41 62   27   337 589   204   24  
  M0 14 20 25 29 35   18   258 458   248   21  
  M1 25 41 33 42 63   28   333 569   225   27  
  M2 37 88 39 64 122   37   408 818   232   29  
  R 18 24 27 37 41   25   263 486   237   22  
  Note: 1In 1963 and 1965 only the mean P and K values were available. Manure doses per application in treatments M0, M1, M2 and R were 0, 30, 90 and 30 t ha-1, respectively. The manure was added in the years 1961, 1963, 1967, 1972, 1976, 1978, 1979, 1984, 1986, 1992 and 1994.