The: Fixation or Nitroge:n. 17 
evidently growing worse. It was evident that a considerable 
number of trees would succumb, indeed some were already dead 
and conditions were not improving in the least. The water table 
was not within five feet of the surface in an adjoining orchard 
though recently irrigated. The affected area had extended so as to 
embrace nearly the whole of this old orchard. There is a young 
orchard on still higher land which is not yet affected*. By Sep¬ 
tember 13, 1910, the old part of the orchard was practically ruined. 
The water table at that time was not within five and a half feet 
of the surface. In this orchard we have a decidedly sandy soil, 
inclining to a clayey loam in places, and not an adobe soil which 
often becomes muddy at comparatively shallow depths as described 
in Bulletin 155. At no time have we found the water table less 
than five and a quarter feet below the surface and practically no 
roots at a greater depth than two and a half feet, and but few 
below two feet. The surface of this soil is brown and mealy, and 
is rich in nitrates and the orchard is in very bad condition. 
The orchard immediately east of this presents the same con¬ 
ditions of soil with the water plane deeper than five and a half feet 
below the surface. The top soil is brown and mealy and many 
of the trees are dead, some having died in 1909 and others in 1910. 
The orchard immediately to the south is worse than either of 
these as the trees are practically all gone. 
This orchard, No. 7, has been given in such detail' because 
it is the first old orchard planted on this type of soil with the 
water table well below the surface, to which we have made so 
many visits, and in which we have been able to watch the progress 
of the trouble. Orchard No. 5 went rather more rapidly, as did 
also No. 6. The soil of Orchard No. 5 is likewise a sandy loam 
and the water table is likewise low, but the land itself is possibly 
a little less favorably located than that of Orchard No. 7. 
I will give but two analyses of soil from Orchard No. 7, or 
rather I will give analyses of the water-soluble portions of surface 
samples, one taken from near a young tree, seven or eight years 
old, which was burned but slightly at the close of the season, 
September 13, 1910, No. 1014; the other No. 1071, taken in 
May, 1911. The water-soluble of No. 1014 equalled 2.974, and 
of No. 1071 equalled 6.276 percent. 
