264 ARTIFICIAL MANURES [chap. 



consumed in situ by sheep. In such cases the land is 

 already rich enough ; in fact, it contains too much readily 

 available nitrogen to give rise to the best quality of 

 malting barley. But when barley follows wheat on 

 some of the poor soils, a fertiliser is required, and this 

 should be composed of a little nitrogen and a fair 

 amount of phosphates. Oats can be treated in much 

 the same way as barley, but they are often grown on 

 land which has just been broken up from pasture and 

 grass, in which case they are rarely likely to require 

 much fertiliser. Of all the cereal crops, maize will 

 respond most freely to fertilisers ; to it should be given 

 all the farmyard manure that is available, 200 or 300 

 lb. per acre of acid phosphate, and perhaps a later 

 dressing of some active nitrogenous manure like nitrate 

 of soda. Of the root crops, swedes are specially 

 dependent upon phosphoric acid, and, whether this 

 crop is grown by the help of farmyard manure or by 

 artificial manures alone, it will be found necessary on 

 all classes of land to use for it 4 or 5 cwt to the acre of 

 superphosphate or basic slag. Little nitrogen is wanted, 

 because the crop is growing in the warmer period of the 

 year and after a very thorough preparation of the soil, 

 so that the production of available nitrogen compounds 

 is going on actively in the soil. Mangolds, on the other 

 hand, are more deeply rooted plants, and are sown at a 

 cooler time of year; it is found by experience that 

 they respond to very considerable quantities of nitrogen, 

 and that they also pay for application of manures 

 containing potash, though phosphatic manures are less 

 necessary. Clovers, beans, lucerne or alfalfa, and other 

 leguminous crops are rarely manured ; they should not be 

 given nitrogen, but they will respond to dressings of 

 phosphates and potash, especially upon the lighter and 

 sandier soils. 



