28 



of plant food, as one of our youngest orchards, a seven-year old, is 

 responding strongly to fertilization, while some older ones have prov- 

 ed unresponsive. The big fact is that when such results as these are 

 obtainable anywhere, it raises a strong suspicion that similar bene- 

 fits may be obtained in many other orchards. And these results show 

 beyond peradventure that in some orchards apple trees, like other 

 plants, respond strongly and directly to applications of plant food. 



Experiments on Cultural Methods. 



Closely associated with the question of plant-food, is that of 

 soil moisture. It is the available moisture that determines in a large 

 measure whether or not apples shall attain their proper size ; and it 

 is largely to modify moisture supply that the various cultural meth- 

 ods are followed. The plan of our experiments comparing these 

 methods is shown in Figure I. 



Plan of Experiment on Cultural Methods and Manures. 



As shown in the figure, this experiment tests four methods of 

 soil management, viz. : clean tillage, tillage and cover crop, sod 

 mulch, and sod. Each treatment occurs both without fertilization 

 and with it. The stable manure is applied annually at the rate of 

 12 tons per acre; and the commercial fertilizer at the rate of 30 lb. 

 of nitrogen (NO), 60 lb. phosphorus pentoxid (P2O5), and 100 lb. 

 of potash (K2O). 



On the mulch plot all herbage remains in the orchard, the first 

 cutting being raked to the trees as a mulch, and an additional mulch 

 of old straw, swamp hay or buckwheat straw at the rate of about 

 three tons per acre is applied annually. In this latter respect it dif- 

 fers from the so-called "Hitchings plan," and as a conserver of 

 moisture it is undoubtedly very much better than that plan. On the 

 sod plot, the first cutting of herbage is removed from the orchard 

 and the second is left where it falls. The tillage plots are all culti- 

 vated until early in July, when those receiving the cover crop are 

 seeded to crimson clover, hairy vetch or medium red clover and 

 alsike, either singly or in combination. The results to date are from 

 the unfertilized plots of the young orchards, and are shown in 

 Table V. These results and those in later tables on young orchards 

 have been obtained by combining the results from three orchards, 

 whose age as noted in Table I ranges from seven to sixteen years. 



TABLE VI. 



Effect of Cultural Methods on Yield, Color, Size and Grov^th, 

 Without Fertilization. 



Expts. 217, 218 and 219. Young orchards, (a) Yield. 



1907-9. 



I. 



Clean 

 Tillage. 



IV. 



Tillage and 

 Cover Crop. 



VII. 

 Sod Mulch. 



X. 

 Sod. 



Totals, 3 years, 



15048 lb 

 108.4 

 100. 



16057 Ih 

 II5-7 

 106.7 

 100. 



17776 tb 



128. 1 

 118. 1 

 no. 7 



13880 tt) 

 100. 



