110 



On the Cultivation of Oats. 



sands and gravels of an incohesive texture. It has long been 

 remarked in the case of light soils long under cultivation, that a 

 second application of lime, if not injurious, is at least not 

 beneficial to the oat crop ; and that an overdose of caustic lime, 

 or of purely calcareous chalk, is frequently productive of the 

 worst results. Several instances of this have come within the 

 writer's observation. On a light trap soil that had been once 

 overlimed, the oat crop for several rotations of five years' interval, 

 lost its green colour, and turned brown when the plants were in the 

 shot-leaf ; and this occurred independently in a great measure of 

 the character of the season ; and although the evil was undoubtedly 

 more aggravated by a continuance of dry weather at the time, yet 

 an abundance of rain did not prevent the plants from becoming 

 scorched, as it is usually termed. Other instances might be men- 

 tioned of light gravelly soils being rendered incapable of growing 

 oats for a long time in consequence of having received a heavy 

 top-dressing of very rich calcareous shell marl found in beds 

 under a layer of peat. Such effects are seldom observable on 

 deep alluvial soils — whether composed of clay, loam, or black 

 mould — but on all light soils composed principally of gravel, sand, 

 loose brown earth, or decomposed peat long under cultivation, 

 lime should be very sparingly used, as an overdose is fatal to the 

 success of the oat crop. These soils are naturally too loose in 

 their texture, and this evil is greatly aggravated by the use of too 

 much caustic lime or even of shell marl. So far as the writer's 

 experience and observation extend, the practice of liming loose 

 mossy, or gravelly soils, long under cultivation, has always proved 

 mjurious to the oat crop for a long time afterwards; and as on 

 the former of these this is the only grain that can be profitably 

 cultivated, it becomes the more necessary to avoid an error so 

 hurtful to their fertility. In reclaiming peaty soils at first, the use 

 of lime is quite indispensable, in order to decompose the inert 

 vegetable matter, and neutralize the tannic, ulmic, and humic 

 acids they contain ; but after the soil is fairly formed, and has 

 been reduced to a mass of loose black mould by cultivation and a 

 course of cropping, the use of bone manure is greatly to be pre- 

 ferred either to caustic lime or shell marl. The use of clai/ 

 marl, on the contrary, may very properly be adopted on all light 

 soils, as it carries along with it its own antidote in the shape of a 

 large proportion of aluminous matter, which renders the soil to 

 which it is applied more cohesive, and consequently more ab- 

 sorbent and retentive of moisture. 



There are also several kinds of moory soils on which oats refuse 

 to grow, especially those lying on a subsoil of mixed clay, sand, 

 and oxide of iron, hardened together by infiltration from above, 

 and known as Moor-band soils. Both wheat and barley can be 



