38 



fill the soil, and the soil itself is in a relatively compact 

 condition, — unfavorable to the rapid percolation of water. 

 The writer has in a number of instances seen unmistakable 

 evidence, in the second season following its application, of 

 the beneficial effects of a heavy dressing of nitrate of soda. 

 This observation, however, was made upon soils containing a 

 large jjroportion of very fine particles, and therefore naturally 

 compact and relatively impermeable. Even in the case of 

 such soils, however, much care should be taken to apply 

 nitrate of soda as near as possible at the time when the crop 

 is ready to make use of it. It would be a mistake, espe- 

 cially in the case of the lighter soils, to apply nitrate of soda 

 in early spring. It should be held until the weather is 

 fairly settled and the grass is beginning to make considerable 

 growth. In average seasons from about the 1st to the 10th 

 of May will i)robably be found to give the largest increases 

 in the crop. The quantity of nitrate of soda which may 

 wisely be used in top-dressing mowings doubtless varies 

 widely with soils. Wheeler finds that in Rhode Island ap- 

 plications running up to 300 or 350 pounds per acre prove 

 profitable, and, indeed, that there is a larger profit from the 

 use of such amounts than follows the use of smaller quanti- 

 ties. On some soils — and many of the fields of the college 

 farm seem to have soils of this character — so heavy an 

 application would usually prove inadvisable; it would render 

 the crop likely to lodge. It has been found on the college 

 farm that about 200 jiounds per acre seem to be as large a 

 qmintity as it will ])ay to use. There must, of course, as 

 will be at once understood, be a wide difference in the tend- 

 ency to lodge under lieavy nitrate manuring with the season, 

 and no doubt also with the species of grass. In relatively 

 dry seasons the heavy applications may prove usefid, but in 

 seasons characterized by frequent and sufficient rainfalls more 

 moderate applications seem preferable. Wheeler has pointed 

 out, as also have others, that the hay produced under heavy 

 applications of nitrate of soda is richer in protein than that 

 produced where less nitrate is used; but if the more li])eral 

 use of nitrate is followed by the lodging of the crop, the 



