STATISTICAL SUMMARY 



In the foregoing pages some of the fundamental and significant character- 

 istics of each region have been expressed numerically. It will now be very in- 

 structive to bring together as many as possible of such numbers in a single 

 table for purposes of comparison, and see what conclusions may be drawn 

 from them. 



It has been stated in the introduction that in northern Florida, if not else- 

 where, the differences in vegetation, density of population, etc., between neigh- 

 boring regions seem to depend on soiL and topography more than anything else. 

 And one of the purposes of this report is to show how a study of the native 

 vegetation may indicate the character of the soil, and more particularly its ag- 

 ricultural value. But unfortunately our knowledge of the soil in this area is 

 still so imperfect that it is difficult to make definite correlations. We have in- 

 deed many physical or mechanical analyses of soils, thanks to the activity of 

 the U. S. Bureau of Soils, but no one seems to have ever pointed out any close 

 correlations between such analyses and the vegetation or even the productivity, 

 beyond the bare fact that a good soil ought to have a certain amount of silt 

 and clay. Chemical composition seems to be more significant (though some 

 limiting factors often have to be taken into consideration, as intimated in the 

 footnote on pp. 175-176), and some correlations between evergreens and potash, 

 Ericaceae and lime, etc., have already been indicated. But at present we have 

 chemical analyses from only ten of the twenty geographical divisions, and seven 

 of those are represented by only one analysis each ; and it is of course impos- 

 sible for a single soil sample, no matter how carefully selected, to be typical of 

 a somewhat diversified region. Consequently it would be rather risky to base 

 any important conclusions on these data. 



Another index of the fertility of the soil is the amount of fertilizer used 

 by the farmers. Of course in the long run nearly as much mineral plant food 

 should be put back into the soil as is removed by crops, regardless of the orig- 

 inal fertility; but in most parts of Florida agriculture is as yet a comparatively 

 undeveloped industry, and the farmers are still drawing on the natural re- 

 sources of the soil to a considerable extent. Consequently the least fertilizer 

 is generally used on the richest soils, and vice versa. 



Statistics of the annual expenditure for fertilizers in each county are read- 

 ily obtained from both -state and government census reports (but were discov- 

 ered too late to be mentioned in the earlier pages of this report). But nat- 

 urally there are several chances of error in trying to obtain the average amount 

 of fertilizer used per acre in different regions from the census returns. First, 

 in regions where the amount of cultivated land is very small a slight variation 

 in the total amount of fertilizer used in different years may make a consider- 

 able difference in the amount per acre, and the census year might not be an 

 average year. Second, in regions which do not cover as much as half of any 

 one county it is impossible to apportion >!ie fertilizer among different regions 

 in the same county accurately. A similar difficulty was encountered in appor- 

 tioning the population and improved land (see p. 188), but it is more accentu- 

 ated in the case of fertilizer, which seems to vary more from one region to an- 

 other than the population, in Florida at least, and is not so easily checked up 



26 393 



