222 FARMYARD MANURE [chap. 



year some protection from cold and drying winds. At 

 Rothamsted on the permanent grass plots it is often 

 noticed that the plots which receive applications of 

 farmyard manure once in every four years start a little 

 earlier and make a quicker growth than the others. 

 This mulching effect partly accounts for the great value 

 attached to dung as a dressing for permanent grass 

 land on open chalky soils, as in Wiltshire, where 

 it is customary to reserve all the farmyard manure 

 for the grass and farm the arable land entirely with 

 artificial manures, aided by the folding off of catch 

 crops. Such a practice is wasteful of the farmyard 

 manure as a fertiliser, for the loss of nitrogen from 

 a la)'cr spread loosely over the ground until it decays is 

 considerable, but the waste is tolerated in view of the 

 gain to the physical or mechanical condition of the 

 land. 



In ordinary mixed farming undoubtedly the best 

 way of utilising farmyard manure is to apply it to the 

 root crops, and especially to mangolds and potatoes. 

 Swedes require much less nitrogen than do the other 

 root crops. They also require a firm but fine tilth ; in 

 consequence, not more than lo to 12 tons of dung 

 per acre should be given for Swedes and it should be 

 applied in the autumn, in order that it may become 

 well rotted down before the spring cultivation begins. 

 But up to 20 tons of dung per acre can be profitably 

 employed for mangolds and potatoes, and it can if 

 necessary be applied immediately before sowing. Any 

 surplus dung, after the requirements of the root crops 

 have been satisfied, is probably best given to the young 

 seeds in the early winter, to act both as a fertiliser 

 and as a mulch. The seeds benefit greatly, and at the 

 same time much of the added fertility is retained for 

 the corn crop that follows ; manuring the young seeds 



