ORCHARD SOIL MANAGEMENT METHODS 



35 



Table 20. — Moisture Determinations on Sod Cultivation and Cover Crop 



Plots 



(Light sandy loam in New Hampshire) 



(After Gourleif) 



Surface soil 



At Harpenden they found during May, June and July an average of 4 per 

 cent, more moisture in tilled soil than in grass land; in Ridgmont soil, grassed 

 land in August and September contained on the average 0.7 per cent, more water 

 than tilled land. In no case did the amount of moisture appear to be the chief 

 factoi- in tree growth. Irrigation increased the vigor of fruit trees growing in 

 grass land, but did not make them as thrifty as those grown in tilled ground. 



The New Hampshire and the English results agree in the superior 

 growth made by trees in tilled ground, despite the absence of significant 

 differences in moisture, or indeed, despite the frequent superiority of 

 grass land in moisture content. In these cases there is evidence of the 

 effect of other limiting factors, some of which are discussed in the section 

 on nutrition. 



Special cases deserve passing consideration. The Hitchings orchard 

 in New York showed under test as good results in growth and yield under 

 the sod-mulch system as under tillage.^*' This condition is explained as 



