ORCHARDING WITH EARTHWORMS 79 



is a hard-headed, successful orange grower and business man 

 who has made money growing oranges. He has been growing 

 oranges all his life and his experience covers a period of more 

 than forty yiears. He is well educated, well informed, methodical, 

 and practical ; and, as he has kept careful records for many years, 

 he has his data and knows what he is talking about. The ten- 

 acre tract comprising Hanford Loam is one of the outstanding 

 groves of the state. We were amazed at the size and luxuriance 

 of the trees. Many of the leaves were of such unusual size 

 as to be almost unbelievable when compared with the foliage 

 of the average orange tree. 



Mr. Hinckley's own story of his experience in developing 

 this grove conveys the facts in a most forceful manner. After 

 our visit to his place, we wrote him a letter requesting a report 

 for our records. Under date of October 17, 1939, we received 

 the following letter. 



DEAR DOCTOR BARRETT: 



I have your letter of October 10th and will try to give 

 some information that will be of value in your research. 



I might say that my experience with the earthworms is more 

 on the practical side than on the experimental. On one of my 

 ten-acre groves, Hanford Loam, I discontinued all cultivation 

 about eighteen years ago. At that time the twenty-eight-year- 

 old trees appeared to have reached their limit as to size and pro- 

 duction, about three hundred boxes per acre per year. 



The first year after changing my cultural method to one of 

 non- cultivation, I noticed a great difference in water penetra- 

 tion. Plow sole was eliminated, the trees started growing, and 

 they have continued to do so ever since, until now they are 

 large, fine trees, and my production average for the last fifteen 

 years has been about 630 boxes per acre per year. 



Soon after I quit all cultivation, I noticed that the earth- 

 worms were doing a wonderful job of tilling the soil ; they 

 eliminated all plow sole, leaving the ground porous and mellow. 

 I also perceived that they were feeding on the leaves that had 

 accumulated in the furrows and around under the trees. Raking 

 the leaves out from under the trees and placing them beneath the 



