THIRTY-FOURTH FRUIT-GROWERS ^ COX\^NTION. 



163 



furnishins:" a supply of humus, they are also of great value and impor- 

 tance in other respects; The particular value of clover, peas, beans, 

 vetch, and other plants of that family for adding fertility to the soil 

 has been known for hundreds of years, although the reason why these 

 legumes possessed superior cpialities in this respect over other plants 

 is a discovery of modern times. In his bulletin on soil inoculation 

 Dr. George T. Moore has these interesting quotations from the writings 

 of Pliny the elder : ' ' The bean ranks first among the legumes. It 

 iertilizes the ground in which it has been sown as well as any manure. 

 The vetch, too, enriches the soil and requires no attention in its 

 culture." 



But the ancient Romans knew only the fact that these legumes acted 

 like manure; the true reason for the fact remained a secret and baffled 

 many investigators ; and not until the year 1886 was it definitely proven 

 that the legumes are able to acquire and store up nitrogen from the air. 

 This discovery is ascribed to the German scientist ITelriegel. 



Later still, it became definitely known that this fixation of nitrogen 

 from the air is accomplished by means of bacteria which gain entrance 

 to the roots of the legumes. Great interest was awakened in the subject 

 in this country when Dr. ]\Ioore of the United States Agricultural 

 Department perfected a method of soil inoculation with the nitrogen 

 gathering bacteria, and pure cultures were prepared and sent out to 

 farmers in many different states. This has very naturally resulted in 

 giving a special impetus to the growing cover-crops, which has extended 

 even to the orchards of California. But, whatever the cause, the fruit 

 growers are sowing peas and vetches and fenugreek in the orchards 

 far more extensively now than was the practice fifteen years ago. 



I remember that green manuring was practiced successfully by a few 

 orange growers in Redlands years ago, but probably Mr. James Mills, 

 superintendent of the Arlington Heights Orchards, has done more than 

 any one else to demonstrate the feasibility of growing cover-crops in 

 our orchards, and also the very great benefits which follow their use. 

 Although we must admit there are difficulties in handling these crops in 

 the orchard and not every one who has attempted it has been perfectly 

 successful, yet I think the great and peculiar value of cover-crops is 

 appreciated more generally to-day than ever before; and it is not too 

 much to say that this is the best method now knoAvn for maintaining the 

 fertility of our soils. There are many different ways in which we derive 

 benefits from their use. Here are ten different reasons that occur to 

 me for growing cover-crops (legumes) in the orchard: 



1. They provide humus iu the soil, by which the inert fertilizing materials of the 

 soil are made available. 



2. They make it ]iossible to obtain results from tli'^ usp of the cheaper forms of 

 phosphate, such as Thomas slaa: and other unacidulated phosphates. 



3. They store up nitrogen from the air. and therefore act as a direct nitrogenous 

 fertilizer. 



4. They improve vastly the mechanical condition of the soil, making it easily 

 possible to secure the best cultivation. 



T\. They put the soil into a condition to retain moisture. 



They make the soil porous, so that proper aeration is secured. 

 7. They are r. means for overcoming irrisation. hardpan and plow sole, 

 s. While growing, they prevent the washing of the soil by th^ storm waters. 

 0. While growing, they probably assist in pre-,-enting the radiation of heat from 

 the irround in time of a freeze. 



10. They do away with the cultivation of the ground during the winter months. 



