SOILS AND \ MANURES 363 



The Indiana (U.S.A.) Station {Bull. 55, p. 29) manured a CHAP, 

 series of plots which had grown maize continuously for five VIIL 

 years, with about 50 tons per acre in two years, of fresh horse 

 manure, no manure having been used either before or after. 

 Comparing the manured with the unmanured plots, it was 

 found that during twelve years the average yield was about 

 560 lbs. per acre, and on the last year of the twelve about 

 280 lbs. per acre, more on the former than on the latter. The 

 total increase, due to the use of the manure, was about 33^ 

 muids. 



At the Government Experiment Farm, Potchefstroom, 

 Transvaal, the effect of a dressing of 8 tons of dung per acre 

 had almost entirely disappeared in the third year following 

 the application {Holm, 1), indicating that frequent applications, 

 or larger amounts at a time, are necessary to produce satis- 

 factory results. The quantity usually applied in the United 

 States varies from 10 to 20 tons per acre. 



Owing to the size of the farms and the sparseness of the 

 white population in South Africa, the amount of stable manure 

 produced is not sufficient to permit of its use on a large 

 scale, and Holm (1) concludes that the comparatively small 

 amount available on most South African farms can be more 

 profitably used on other crops, such as mangels and potatoes, 

 than directly on the maize crop. In the United States, even 

 to-day, the supply of dung is totally inadequate to the demands 

 of the field crops, and hardly more than is needed for the 

 kitchen garden and a few " truck patches " near the farm-house. 



The value of stable, and kraal, and other home manures, 

 should not be underestimated. The farmer should endeavour 

 to increase the supply of them rather than try to become inde- 

 pendent of their use. But it would be just as unwise to so 

 overestimate the value of home manures as to lead to the policy 

 of ignoring altogether the aid of commercial forms of plant- 

 food. Director Redding of the Georgia State Experiment 

 Station (1) points out that the true farm economy is that which 

 utilizes to the fullest every home resource and then supple- 

 ments their use by the purchase of commercial forms of plant- 

 food in the proportions demanded by different crops, and 

 modified to some extent by the character and condition of 

 the soils to be fertilized. 



