SOIL MANAGEMENT FERTILIZATION OF ORCHARDS. 53 



a better showing from this viewpoint than from that of average total 

 yields per tree. The ashes plot, 2, made a substantial gain during the 

 second period, but made little further gain in the third period. 



It seems reasonable to conclude that under the conditions at this 

 orchard, which is on a sandy soil of inferior fertility, as indicated by the 

 growth of cover crops and other herbaceous plants, the fertilizers apphed 

 have been beneficial to the trees, as indicated by increased growth and 

 greater production. 



Lbs. 

 350 



3es 



300 



^75 



Z.50 



i.00 

 ITS 

 I 50 



100 

 *7S 

 50 

 Z5 







I £-34567© 



Man. Ash. Check Mur. L.G.Sul. Mur-Mg. H.Qr.Sul.SlajSuL. 



Fig. 11. — Average yield per tree by two-year periods (Graves orchard). 





lqll-l^ 



Discussion of Results. 



The results of many orchard fertilizer experiments in this country have 

 shown that, of all the fertilizer elements usually taken into consideration, 

 nitrogen is most likely to produce a response. This response appears in 

 darker colored and more luxuriant foliage, more growth, and often in- 

 creased production of fruit. It may be worth while to consider how far 

 the observed results, especially those of growth, can be explained on the 

 basis of variation in available nitrogen supply. 



The manure plot in the station orchard has plainly responded to the 

 generous supply of nitrogen it has received. Growth, foliage Color, and 

 size and color of fruit have all been typical of trees well supplied with 

 nitrogen. Both the potash plots in this orchard have received small 

 supplies of nitrogen in the ground-bone application of 600 pounds per 



