blackpoint data                                                                     

fert
  N     irrN    plot     bppct

 120      60      1     14.8340
  60      60      1     10.8679
   0      60      1      6.7503
 120       0      2     12.1306
   0       0      2      3.2047
  60       0      2      7.9795
   0     120      3      7.6949
  60     120      3     11.4392
 120     120      3     15.4499
   0       0      4      3.2536
 120       0      4     12.9110
  60       0      4      6.5895
   0     120      5      5.1758
 120     120      5     13.2164
  60     120      5      9.4688
 120      60      6     13.6779
   0      60      6      5.8008
  60      60      6      9.8813
   0       0      7      3.1517
  60       0      7      5.3994
 120       0      7     11.3345
  60     120      8      8.8299
   0     120      8      4.5221
 120     120      8     13.7025
  60      60      9      9.3211
 120      60      9     14.6124
   0      60      9      6.5583