26 BOTANICAL GAZETTE [JANUARY 
‘TABEE &, 
SHOWING RESULTS OF ANALYSES OF SOILS OF NORTHERN MICHIGAN. 
Average, 6 
a Tittaba- | P " s : 
= Location Munsee a Gaylord —— Lake co. Fe 
I Valley ; aa and Oscoda 
e 
z NATURE OF SOIL Clay Loam Loam Loam Sand Sand 
2 ay ( 
@ | WaTeR capacity | 51.40 45-40 39.60 39.10 35-30 33-00 
z > 
“ | Forest tyre | Hardwood | White pine | Hardwood | Hardwood | Jack pine | Jack pine 
Siea Ses 67.20 75-54 QI.52 69. 39 92.48 Q4.22 
% | Alumina..... 6.31 10.62 2.93 8.35 oe | Ricwes 
Se ee ee 7.91 3.80 0.90 5.80 EeSo 1.88 K 
= OOP ae 1.64 0.94 0.40 rvES O.35 Oo. 37 
eS "33 0.48 0.13 0.98 0.30 0.06 
Sec taie J 1.85 1.96 o.61 1.95 O73 0.85 
oan et ae see ¥.25 0.28 Eas 0.32 0.27 
g PESC),.....'55 ©. 30 0.26 0.10 0.25 0.06 0.01 
5 H;PO,....--- °.49 0.44 0.14 0.28 0.14 0.08 
c 
materials 7-48 2.97 2.20 4-73 1.22 2.16 
more marked when the humus lies as a distinct layer on ee 
than when it is distributed through the underlying soil. The humus 
layer acts like a sponge filled with water, and allows the water to oad ee 
It will be noticed in the table that sandy soils usually exhibit a 
marked scarcity of soluble salts. This fact is perhaps to be explained. 
by the “leaching” action of the percolating waters, as well as by the _ 
thorough washing to which these soils were subjected at the time of 
their deposition. The water of precipitation percolates rapidly through © 
these porous soils and may often wash the soluble salts down vege 
the level of the ground water, this process being termed “leaching.” 
‘In humus-covered soils, it is probably not to the point to determine J - : 
humus content and water capacity after the humus has been mixed | 
with the loamy layers; the effect of the organic substance is very mu 
depth of 20 to 30°™; nothing is said regar 
reports from which these data are derived. 
—— Ir aor the water capaci 
of several ail samples ok 
