USE OF EARTH SATURATED WITH MANURE. 147 



yard manure (500 kilogrammes or 1000 pounds) to con- 

 tain 660 pounds of water, 6 pounds of potash, and 12 

 pounds of ammonia ; and if this were mixed with 1 

 cubic metre of earth, of which 1 cubic decimetre ( = 61 

 cubic inches) absorbs 3000 milligrammes ( = 46 '2 grs.) 

 of potash, and 6000 milligrammes ( = 92*4 grs.) of am- 

 monia ; then, after the complete decay of organic matter 

 in the manure (about 25 per cent, of its weight), and 

 the evaporation of one-half of the water, the result 

 would be 1J cubic metre of earth fully saturated with 

 all the nutritive substances in the manure. Soils that 

 will absorb the stated amount of potash and ammonia 

 are everywhere to be found, and the farmer will have 

 no difficulty in choosing the earth most suitable for his 

 compost heaps. 



It is well known that dung exercises a mechanical 

 action also, tending to diminish the cohesion of a com- 

 pact soil, or to make a heavy soil lighter and more 

 porous. For soils of this kind composts are not so well 

 suited ; and, instead of the earth, some very loose body 

 ought to be substituted for mixing with the manure. 

 Turf-dust will be found to answer the purpose best.* 



If the crops obtained from many fields by manuring 

 with farm-yard manure, bone-earth, guano, and in many 

 cases also with wood-ashes and lime, are compared with 

 what the same fields will yield in the unmanured state, 

 the effect of these manures seems truly marvellous. 



The yield of an unmanured field must correspond 



* It is, perhaps, much more important than manuring with composts, 

 which always involves much labour and more carriage, to take advantage 

 of the absorbent properties of earth and turf, for fixing the nutritive sub- 

 stances contained in liquid manure. By covering the ground of a dung- 

 hill, on an area of 10 metres square (=10'5 sq. feet) with a layer of loose 

 turf, 1 metre (= 3*3 feet) deep, a bed of 100 cubic metres (= 3,500 cubic 

 feet) of turf is formed, into which the liquid portion of the manure in the 

 dunghill may safely be allowed to soak without the least risk of losing the 

 smallest portion of its useful ingredients. The turf may then be used, like 

 dung, for manuring, and of course must be renewed every year. On fields 

 which are not tilled, such as meadows, liquid manure will naturally act 

 with greater rapidity. The turf found in the neighbourhood of Munich, 

 when reduced to powder, absorbs 7'892 grammes (=122 grains) of potash, 

 and 4' 169 grammes (=64 grains) of oxide of ammonium, per 1000 cubic 

 centimetres (=61 cubic inches) weighing 330 grammes (1I| ozs.). 



