163 
E. F. Ladd, of the Agriculture Experiment Station at Geneva, 
N. Y., urges the necessity of a more thorough and systematic study 
of climate and soil (Agr. Sci., Vol. IV., p. 36) in order that we may 
better understand the great diversity and contradictions in the experi- 
mental field work, so called. Thus one year’s experiments at the same 
station and with all possible care will show that the ‘ Welcome ” 
vats are vastly more productive than the * White Russian,” and the 
very next year reverses this decision. In the same year a neighboring 
experiment station operating on the same varieties arrives at opposite 
conclusions. In 1887 the observations showed that fertilizers did not 
affect the chemical composition of the grasses, but in 1888 the influ- 
ence was very marked. Ladd finds that the contradictions in the 
reports of oat crops for 1885 and 1886 at the Ohio and New York 
stations are apparently due to considering only such factors as 
monthly rainfall and temperatures. He urges that the soil tempera- 
tures, sunshine, wind, the humidity in the soil, and the aeration of 
the soil are equally important factors. Any season will give some 
sort of a crop, but the maximum crop must depend upon the ferti- 
lizer and the relation of the fertilizer to the season. Thus Waring- 
ton has shown that a dry and warm season is most favorable for the 
action of nitrate of soda, while a moderately wet season is most favor- 
able for the action of sulphate of ammonia. The reason of this 
appears to be that plants are unable to appropriate to their use the 
sulphate of ammonia until the salt has become nitrified, and this phe- 
nomenon of nitrification does not take place except under the influence 
of a certain amount of moisture in the soil. A soil that conserves its 
moisture for a considerable time and is properly cultivated to permit 
the free permeation of the air gives the best results with sulphate of 
ammonia, but does not necessarily give the best results with the 
nitrate of soda, since this is so soluble as to be soon drained away out 
of reach of the plants. Thus in different seasons, with different ferti- 
lizers, we have the crops of wheat shown in the following table: 
| _Hecto- 
| liters per 
hectare. 
Nitra telofL soda;and. jal wet season (1882) =-._. --- .----+-.2---.----_--:-- ee Sa eee 23.45 
Nibrateot soda anda dry watm season (188%) <==" =s2225- 222 = = 2222 52-225 2 ee 31.57 
Sulphate of ammonia, wet season (1882)--.....--.----------------- Ae Blea oe Shee Sais eM er eee 28. 86 
Sulphate of ammonia, warm dry season (1887) __.._...---.------------------------x---- 23.56 
Again, crops, like animals, have a certain limit to their capabilities ; 
if the maximum yield is 50 bushels per acre, then it is a waste to put 
on more fertilizer than needed to attain this limit. Evidently, there- 
fore, we have to study the relation of the climate to the fertilizers 
and the soil in order to ascertain a very important item in the relation 
between climates and crops. 
