1893.] PUBLIC DOCUMENT — No. 33. 65 



instances a one-sided exhaustion of the land under cultivation. 

 This circumstance has frequently been brought about in a marked 

 degree by a close rotation of mixed grasses (meadow growth) and 

 of our next main reliance for fodder, the corn (maize). Both 

 crops require potash and phosphoric acid in similar proportion 

 (4 potassium oxide to 1 phosphoric acid), and both require an 

 exceptional amount of the former. 



Tliere is good reason to assume that the low state of productive- 

 ness of many of our farms, so often complained of, is largely due to 

 the fact that crops have been raised in succession for years, which, 

 like those mentioned, have consumed one or the other essential 

 article of plant food in an exceptionally large proportion, and 

 thereby have gradually unfitted the soil for their remunerative 

 reproduction, while a liberal supply of other equally important 

 articles of plant food is left inactive behind. 



As the amount of available plant food contained in the soil rep- 

 resents largely the working capital of the farmer, it cannot be 

 otherwise but that the practice of allowing a part of it to lie idle 

 must reduce the interest on the investment. 



Personal local observation upon the lands assigned for the use 

 of the station has furnished abundant illustration of the above- 

 described condition of farm lands. In one instance it was noticed 

 that apiece of old, worn-out grass land, after being turned under 

 and properly prepared, as far as the mechanical condition of the 

 soil was concerned, produced, ivithout any previous a2)2^licat>on of 

 manure, an exceptionally large crop of horse beans and lupine, — 

 two reputed fodder crops. 



A similar observation was made during the past season, when 

 lands which for years had been used for the production of English 

 hay and corn were used for tlie cultivation of Southern cow-pea, 

 serradella and a mixed crop of oats and vetch, to serve as green 

 fodder for milch cows. The field engaged for the production of 

 these crops was not manured, because it was to be prepared for a 

 special field experiment during the following season. An area of 

 this land which, under favorable circumstances, would not produce 

 more than six tons of green grass at the time of blooming, yielded 

 nine to ten tons of green vetch and oats, ten tons of green Southern 

 cow-pea, and from twelve to thirteen tons of green serradella. 



The exceptional exhaustion of our lands in potash has also been 

 shown abundantly by detailed description of experiments with 

 fodder corn in previous annual reports. 



Our local results during past years tend to confirm the opinion 

 held by successful agriculturists that dry grass lands which are in 

 an exceptional degree inclined to a spontaneous overgrowing by 



