THE 



GARDENER'S MAGAZINE, 



JANUARY, 1843. 



ORIGINAL COMMUNICATIONS. 



Art. I. On the Theory of Manures. By R. Lyme urn. 



The year 1842 has been distinguished by a vast variety 

 of efforts to elucidate the subject of manures; and the many 

 tables published, opinions given, and experiments recorded, have 

 added immensely to the bulk of information from which rules 

 for practice must ultimately be deduced. That much disap- 

 pointment and many unaccountable results have been produced 

 should not damp our endeavours. The difference of soils has 

 a great effect in producing these : they vary so much in their 

 physical properties, both naturally and artificially, that experi- 

 ments will require to be often and carefully repeated on different 

 soils, in different seasons, and on a large scale, before they can 

 enable us to form rules for our guidance in practice. A soil 

 naturally porous will produce very opposite results from a 

 sodden stiff soil, and will require very different treatment ; if 

 this be neglected, or interfered with by accident, the result may 

 differ very much from expectation. If the season is likely to be 

 wet and cold, the porosity should be encouraged; if dry and warm, 

 the ground should be rolled and compressed ; this may be omitted, 

 or the weather may be so very dry that the crop may fail even 

 although this is attended to. If the soil is cold and wet, it may 

 be much improved by cultivation. The skilful cultivator will 

 take advantage of tids of weather, and may make frost, drought, 

 and even wet, assist in pulverising and producing that great 

 requisite, a plentiful supply of moisture to the roots, absorbed 

 from the small pieces of the soil, without an overdose to gorge 

 up the channels of communication between the air and soil. 

 Dry hot manures, strawy and turfy, suit wet soils generally 

 best ; and cold wet manures the dry soils. But seasons may 

 reverse this order. In cold wet summers, dry hot manures 

 may do best even in dry soils ; while heavy wet land, if worked 

 wet in spring, and a dry summer succeed, may be so coarse in 

 the pieces, so open and porous, as to be benefited most by cold 

 wet manures. It makes no odds how much, and how usually 

 3d Ser.— 1843, I. b 



