32 On Liquid Manure. 



counterbalanced by the small proportion of fertilising matters 

 supplied. 



Again, clay soils, whether fertile or barren, and all land that 

 is moderately stiff, like the majority of soils in England, must 

 by a heavy dose of liquid manure be rendered closer. Such 

 soils certainly would not be improved in their physical character 

 by an excess of water. The use of liquid manure at a time when 

 such land is more than sufficiently wet is therefore objectionable. 

 But it is equally objectionable when stiff soils get too dry. In 

 summer soils of that description crack in all directions, and 

 the liquid manure then runs through the cracks instead of 

 passing through the soil, or it moistens the soil but very im- 

 perfectly. Much of the liquid manure is thus lost, and, moreover, 

 injury is done by the insufficient proportion of manure that is 

 absorbed by a thin layer of the surface soil, for it causes at 

 first a more rapid development of the young plants, which 

 receive a sudden check as soon as the small quantity of moisture 

 is all evaporated. 



We thus observe that, generally speaking, neither the chemical 

 nor physical characters of clay soils, and others partaking more 

 or less of the same nature, are favourable to the introduction of 

 the system of liquid manuring. And since by far the greater 

 part of the cultivated land in this country is more or less reten- 

 tive, I feel assured that liquid manure will never be extensively 

 employed by British agriculturists, but that its use will be con- 

 fined to land of a light porous character. 



The experience of those who profess to have used liquid 

 manure with much benefit on clay land may be regarded as 

 contradictory to my views on the subject. But I would observe 

 that, as far as I could learn, the application of liquid manure on 

 heavy land, where it is said to have produced astonishing results, 

 was always preceded by thorough draining, subsoil ploughing, 

 deep cultivation, clay-burning, and liming, each of which pro- 

 cesses is well known to effect radical changes in the constitution 

 of heavy land. Bearing in mind the experience of Mr. Smith 

 of Lois-Weedon, and others who have practically tested the utility 

 of deep cultivation ; and on the other hand the failures of those 

 who have applied liquid manure upon land not previously im- 

 proved by any other process than thorough drainage, it appears to 

 me, to say the least of it, doubtful, whether the improvements in 

 such soils are due to the application of liquid manure, or to 

 the processes of subsoiling, liming, and burning. Any one of 

 these processes effects a radical improvement in heavy land, and 

 much more conspicuous will the improvement be if all three 

 are resorted to in succession, which was the case in one instance 

 that has come under my notice. 



