| Show natural and acquired A soil is naturally fertile is much more valuable to the fanner than one which is fertile only by alio licup of tho natural fertility of the soil comparatively speaking 13 a permanent quality and can only lo 10 injured by he continuance of an exhaustive system of cropping for a long lime acquired fertility is quite a dill crant mailer it is duo to alic accumulation of mau urial ingredients in may be or entirely withdrawn ly cropping in a short liun continued cropping without results in a reduction of tho stock of available fertility in every soil A soil however which is goon exhausted for ono soi t of crop may contain an food supply for a crop of another kind tho wisdom of a rotation of crop which long defers alio of exhaustion alic more available anre of course tho bacomo a poor boil will wear out sooner than a rifer one a shallow ono exhausted adoner than 1 deep one and u light soil sooner than a aisil one all boils roils more or acs i store ot plant food in a dormant condition ca of gradual development As cropp ln removes plant food from the soil it is replaced moro or less rapidly y the acet aoi of iho weather alio ailion of carlli worms etc tho of natural soil is greatly accelerated by artificial means anch as tillage anil diio application of manures willi 1 system of rotation of crops and fertilizing alic fertility in anay bo mado to itself year lifter year ins toad of bc coniing ai is too often lie cae a long pa of mr laws of england to iho alic results of nn CK acara the two crops alic oila acro t and in alio same bichl alio abo samo in bo far ns colluro wm concerned and allm bvrd abo same tho only was that in ono case had been unassisted by 1111 aure and in alio oilier alo soil each year received which acio aund to bo to the crop tim result of iho latter treatment was n return of weight of grain ami four times the weight of straw for an expenditure of maugro which left i of per cent on its cost I 1 A SAI antonio icv man atol somo grave i louba for pur poses achl aan |
