MANURES SUITED FOR SPECIAL CROPS 221 



the turnip crops previously, should be well manured with 

 phosphates, leaving merely their residues for the clover. 

 Other leguminous crops like lucerne and sainfoin may be 

 treated in the same way. As lucerne and sainfoin will stand 

 longer than clover, the barley amongst which they were 

 previously sown should be very well manured with phosphates. 

 Top dressings of potash salts may be used, and occasionally 

 a little nitrate of soda to start the young plant in its first 

 stages of growth. 



Grass Lands. Clover by itself is not so satisfactory as 

 in admixture with other vegetation, such as grasses. A 

 grass crop does not consist of a single botanical species, but 

 always includes a great variety of species. 



A perpetual competition takes place between the different 

 species, each of which is endeavouring to crowd its neigh- 

 bours out of the field. The appearance of the pasture is some 

 guide to the type of manure to be used. Creeping bent grass 

 is usually prevalent on heavy lands deficient in phosphates ; 

 cocks-foot and brome grass is often to be found on sandy, 

 droughty soils, where potash is necessary. Land laid up 

 for hay with little or no grazing must receive regular manuring. 

 To what extent fertilizers can be expended on this crop 

 depends largely upon the capacity of the district. An 

 instructive contrast of the effects of different climates may 

 be made by comparing the results of Northumberland, at 

 Cockle Park, and those obtained in Hertfordshire, at Rotham- 

 sted. Although the unmanured plot in each of the two 

 places gives yields of hay which differ by only i cwt. per 

 acre, the best plot at Rothamsted yields 24 cwt. more hay 

 than the best plot at Palace Leas in Cockle Park. Under 

 such circumstances the monetary return could not possibly 

 have any relationship in the two places, since the profits by 

 using fertilizers at Cockle Park are limited so severely by 

 its bleak situation. (See p. i.) 



A comparison of these and similar experiments shows that 

 where climatic conditions preclude the possibility of obtaining 

 bumper crops, the use of farmyard manure and slag give the 

 best hope of profit. Robertson has shown that mineral 



