46 The Fruit-Growers Guide-Book 



the custom has been of continuous cultivation, with the 

 result that the tilth of the soil is ruined and that it bakes 

 badly after each irrigation. 



Cover crops are of three kinds: (1) Those grown in 

 seasons between other crops; (2) those which occupy the 

 land for one or more seasons before they are plowed un- 

 der; (3) those which are sown late in the season for the 

 purpose of protecting the soil during the winter. 



In general orchard practice cover crops are sown late 

 in the summer and allowed to remain throughout the 

 winter when they are to be turned under the following 

 spring and become a green manure. For such purposes 

 a number of different kinds of crops are used, depending 

 largely on the soil, climate and the needs in hand. 



Winter rye is one of the most useful cover crops for 

 the orchard. It may be sown at any time from the mid- 

 dle of August until November, and grows all winter where 

 the climate is not too severe, resuming growth again early 

 in the spring. It is very efficient in gathering the soluble 

 nitrates that might be leached from the soil. It is especi- 

 ally well suited for light soils. 



Buckwheat and oats are sometimes used, especially in 

 the Northern states, but they are killed by the winter 

 weather and need to be planted early in order to get a 

 good cover over the soil before winter. 



Winter vetch is useful on the medium loamy soils and 

 is hardy as far north as Massachusetts in well drained 

 locations. It is a legume, and consequently increases the 

 nitrogen supply in the soil. It does best when sown with 

 rye, and is not well adapted to stand hot weather. 



Canada field peas are used as cover crops in the North- 

 ern states, and in the higher altitudes of the West where 

 the climate is cool. They are very effective where they 

 thrive. 



Crimson clover is useful in sections where it will do 

 well as along the eastern part of the United States. South 

 of N f ew Jersey it is hardy, but north it is uncertain. It is 



