CHE REFERENCE LIBRARY - ZetaTalk

176 THE NURSERY-M-ANUALl~usba&~~, the following statement will be useful : ‘I’he amountof green i:orn necessary to remove an equal amount of fertilizingingredients per acre, takiug the average of the value of thenitroger), phosphoric acid and potash ($1.72) removed by anacre of the trees (3 years’ growth), would be 4,779 pounds.“ Sil;Ige corn raised in drilis usually yields from 12 to 20 tonsper acre, and yet rlr~s not make drafts on the land which precludeduplicating t.he yield the following season ; hence someother pause than soil exhaustion must, he found if the failureto grow a second crop of nursery trees without intermediatecrops is explained.” These conclusions are supported in analysesmade lj~y the ,Xew York State Station (Geneva).All experience proves that a crop of nursery trees does noteshaust the land of its fertility. In fact, it is generally consideredthat land front which trees have just been removed isin good condition and heart for a crop of beans, wheat orpotatoes. Yet, despite this fact, it is also generally consideredthat land can seldom raise two good crops of nursery trees insuccession. Land that has been “ treed ” must be I‘ rested ”in grass or some other crop. This disposition of land to refuseto gro:v two consecutive crops of good trees is not Ann invariableruie, however. ASursery lands have produced good plum treesfor twenty consecutive years. One frequently sees landsyielding apple and cherry stocks for two or three crops in succession.Plums seem to be particularly amenable to thisconsecutive cropping, and they are benefited by applicationsof stable manure. Some other species, as, for example, thepear, do not take so kindly to trea’tment with manure. Becauseof this common experience with iudifl’erent trees grownon treed land, nurserymen with a large business prefer to rentland for th e growing of trees.The chief reason for this condition of treed lands seems tobe t,hat the soil is injured in i.ts physical texture and robbedof its humus by the methods of cultivation and treatment.