163 



E. F. Ladtl, of the Agriciiltuiv Plxjx'riineiit 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 " 

 oats are vastl}^ more productive than the " \Miite 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 

 alfect 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 188.5 and 1886 at the Ohio and Ncav York 

 stations are apparently due to considering only such factors as 

 monthh' 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. 



Nitrate of Hoda and a wet season ( 1882) 



Nitrate of soda and a dry warm season (1^*87) - 



Sulphate of ammonia, wet season (1882) 



Sulphate of ammonia, warm dry season (1887) . 



23.45 

 Sl.r,7 

 28.86 

 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 tiie fertilizers 

 and the soil in order to ascertain a very important item in the relation 

 between climates and crops. 



