MANURES SUITED FOR SPECIAL CROPS 217 



so suitable. Recent trials at Rothamsted have given the 

 best general results with sulphate of ammonia on barley. 

 Barley is grown under somewhat different conditions of 

 tilth, but it may follow wheat, and form a second, or even a 

 third, white straw crop after roots or clover lee. In such 

 cases the high condition of the soil is taken out by the first 

 crop of wheat, and there will be little readily available nitro- 

 gen left. Good malting barley, which fetches the highest 

 prices, contains little nitrogen, and nitrogen manures must 

 be applied sparingly ; but impoverished soils will not yield 

 good barley. It is desirable that the nitrogen should come 

 from the condition of the land rather than from very soluble 

 manures like sulphate of ammonia. Phosphates are very 

 essential for barley, and therefore dressings of superphos- 

 phate may safely be used. Where there is a risk of delayed 

 ripening, a mixture of superphosphate and sulphate of am- 

 monia may be applied ; this gives the young plant an easy 

 start, and enables it to grow away without check. Sodium 

 chloride is sometimes used on light land for the barley 

 crop. Rape dust has also proved very useful where small 

 quantities of nitrogen are needed for barley. A mixture of 

 i cwt. of superphosphate and i cwt. of steamed bone flour 

 provides another very suitable manure ; a little sulphate 

 of potash may be added if the soil is very light. When 

 barley follows roots which have been very highly manured, 

 especially when the roots have been folded off by sheep, 

 the land is already too rich in nitrogen for barley, and 

 therefore no more nitrogen should be used, although super- 

 phosphate may sometimes be applied under these conditions. 

 Where oats are grown on poor land, 2 cwt. of superphos- 

 phate and i cwt. of sulphate of ammonia is a good mixture, 

 but basic slag may often take the part of superphosphate 

 with advantage, since oats suffer when grown on sour soils. 



Root Crops. The greater part of the manure that is 

 made on the farm is applied to the root crops (see p. 205), 

 although in the southern parts of England it is frequently 

 applied to the hay crop instead. Large crops of roots or silage 

 are needed for the maintenance of farm stock. Generous 



