O
I ~I
0






- 

S 0 ::::: :::: ::: fert ili zed

 0o fertilized




 0 10 20 30 40
 TOTAL P (PPM)

 Figure 2.-Total P concentrations at three depths in Leon fine sand five
years after fertilizing loblolly pine with 392 kg/ha of diammonium phosphate.


above-ground biomass while increasing the proportion of roots.
The greatest change was in fine root biomass.
 In all measures of productivity and on all treatments, slash
pine outproduced loblolly pine (Tables 1, 2, 3, and 4).

Nutrient Concentrations

 The effects of water table control and fertilization on con-
centrations of N, P, K, Ca, Mg, Al, Mn, and Zn by tree com-
ponents are presented in Tables 7-14. The analyses of variances
for the element concentrations are summarized in Table 15.
 Nitrogen.-Foliar N levels were not increased by fertiliza-
tion but were significantly increased in both species by water
table control. Nitrogen levels in other tree components were
generally unaffected by treatments. There were significant dif-
ferences between species, with blolly ne having a higher N
concentration than slash pine.