Octuber. '16] 



NITRATES IN ORCHARD SOILS. 



It will here be seen that Plot 1 (the sod plot) has made an 

 average growth of less than 5 inches a year for a period of eight 

 years, Plot 4, 7| inches and Plot 5 nearly 9 inches (8.83 in.) or 

 nearly twice the growth of the plot in sod. It will of course be 

 understood that the trees under cultivation produce many twigs 

 of a greater growth as well as water sprouts and excessive growth 

 in the tops of the trees, but such growth is eliminated from the 

 data and only the normal growth at the ends of the permanent 

 branches is included. Plots 4 and 5 have been of special interest 

 as the soil on these plots is quite uniform and the outstanding 

 difference in treatment is that Plot 5 has a cover crop plowed in 

 annually while Plot 4 has had clean cultivation throughout. In 

 some years there was little difference in the growth on these plots 

 but the past two years the superior treatment of Plot 5 has been 

 showing. At this time we wish to call attention to the greater 

 amount of nitrates found each year in Plot 5 than in Plot 4 as 

 shown in a later table which may explain at least to some extent 

 the difference in growth. The moisture content is slightly 

 superior in Plot 5 but scarcely sufficient to account for the differ- 

 ence in growth. 



Table No. 3. 



Average Annual Yield Per Tree. 

 Number of Apples. 



As regards yield it will be noticed that Plot 1 remains the lowest 

 as was true with growth, while Plot 4 shows a little higher yield 



