ORCHARD SOIL MANAGEMENT METHODS 



39 



Table 21.- 



-The Relative Effectiveness of Soil Mulches of Different Depths 

 AND Different Frequencies of Cultivation^* 



Intercrops and the Soil Moisture Supply. — The influence of various 

 intercrops upon soil moisture conditions in the young orchard has been 

 studied by Emerson.*^ Results of these studies, covering two successive 

 seasons, 1901 and 1902, are presented graphically in Fig. 1. These two 

 seasons afforded more or less extreme conditions of precipitation. The 

 summer of 1901 was characterized by very light rainfall, so light in fact 

 that the trees would have to depend largely upon stored moisture during 

 the period of their most active growth. On the other hand, the summer 

 of 1902 was a season of abundant rainfall. The crops grown in the 

 vegetable plot included water melons, bush beans, pole beans and turnips. 



In commenting upon the results of this investigation Emerson says: 

 "The vegetables dried the soil but little more than clean cultivation. In 

 neither case did the percentage of moisture become dangerously low, even during 

 the protracted drought of 1901, when only a little over 7 inches of rain fell during 

 the 4 months from May to August inclusive. The crops of rye dried the ground 

 much more than any other method of culture tried. Not only was the rye ground 

 somewhat drier, but it became dry earlier, and moreover, since no rains occurred 

 to thoroughly moisten the ground after it had once become dry, the rye plot 

 remained dry nearly a month longer than any of the other plots. Next to rye, 

 the oat crop dried the soil most seriously during the dry season of 1910, though it 

 did not make the soil much drier than corn or cover crops. Its effect, however, 

 was noticeable much earlier in summer and lasted much longer. By the middle 

 of July, when the corn plot was becoming dry, many trees have completed their 

 greatest length growth and do not need so large a supply of moisture as they do 

 earlier in the season. The corn plot was very dry, therefore, only about half as 

 long as the oats plot. The important difference between the cover crop and the 

 corn, just as between the corn and the oats, is that the soil in the cover crop plot 



