MANURE NOT k PERFECT FERTILIZER 221 



When the soil is in a good state of f ertihty, applying the manure 

 for corn seems the better practice. 



Concerning Winter Application. — The common opinion is 

 that severe losses occur when manure is applied to land during 

 winter. On steep hillsides there is danger of heavy losses, since 

 heavy rains and melting snow wash many of the small particles 

 of manure from the field. It is better, therefore, to apply manure 

 to steep hillsides just prior to plowing. 



On level or gently rolling land, losses are generally quite small; 

 and, no doubt are much less than the losses which occur in the 

 average barnyard when the manure is allowed to accumulate there. 



Residual Effect of Manure. — ^The beneficial effect of manure 

 on soils of the heavier types may be of long duration. The best 

 known experiment is the one made at an Experiment Station in 

 England (Rothamsted). For eight successive years manin-e was 

 applied to a piece of land at the late of fourteen tons to the acre. 

 The land was then left in grass without manuring or fertilizing for 

 fifty years. The yields of hay were compared with those on a simi- 

 lar field on which no feitihzation was made. The average increases 

 in yield for each decade, resulting from the previous appUcations 

 of manm-e, were fifty-seven, twenty-fom*, six, fifteen and twenty- 

 eight per cent, respectively.^^ 



Manure Not a Perfect Fertilizer. — General results demon- 

 stiate conclusively that manure alone cannot maintain fertility 

 nor can it be used exclusively in regenerating soils. The continued 

 use of such manure on many dairy farms has led to an unbalanced 

 condition in the soil. Oat crops especially, secure so much nitro- 

 gen that they lodge badly. Many dairy farmers who purchased 

 '^ run-down^' farms, and who sought to improve the soil through 

 the use of manure, have found that phosphate fertilizers, in particu- 

 lar, are quite necessary to supplement the manure to give the results 

 desired. On sands, the reinforcing of the manure with both phos- 

 phates and potash proves most profitable. 



Of all the materials that may be used in reinforcing manure, 

 there are none better than phosphate fertilizers. The Ohio 

 Station has produced conclusive results on this point. The follow- 

 ing table gives the average results of a fifteen-year test on silt 

 loam soil with manure reinforced with phosphates made at that 

 Station (Fig. 148). 



10 The Book of the Rothamsted Experiments, 1917, page 156 



