148 



CALIFORNIA FRUITS: HOW TO GROW T1110JM 



when it is in proper condition to work. To work it when perfectly 

 dry is simply impossible, and if it is plowed when too wet and sticky, 

 it becomes hard, lumpy, and altogether unmanageable. The con- 

 dition which favors best results by tillage must be learned by 

 experience. 



Another mistake, apt to be made where the orchard or vineyard 

 is but one of the branches of a mixed farm, is to put aside the 

 plowing until all the field work is done, and in some seasons the 

 soil in the orchard has become so dry that it turns up in large 

 clods, which are afterwards partially reduced by the harrow, but 

 never put in the fine tilth which should be secured for the retention 

 of moisture and otherwise to encourage the growth and productive- 

 ness of the trees. 



Breaking up Hard-pan. Those who advocate the use of the 

 plow, claim several advantages for it. The chief is that more 

 thorough tilth can be secured. In most, but not all soils, there is 

 formed by cultivation an artificial hard-pan at whatever depth the 

 implement attains, if this depth be kept the same for many succes- 

 sive cultivations. This hard-pan, in some soils at least, becomes 

 impervious to water and is otherwise an injury to the growth of 

 the trees. It occurs in irrigated and unirrigated land alike, but 

 probably is more quickly formed by irrigation. When continuous 

 summer cultivation is practiced, the hard-pan will be found at 

 whatever depth the teeth uniformly reach. The remedy is to plow 

 in winter just below this hard-pan layer and thus break it up, 

 and then by the action of the air and rains it is reduced, and culti- 

 vation may proceed as before. Where the hard-pan is formed by 

 the plow, the ground should be plowed shallow one year and 

 deeply the next, thus alternating from year to year. 



Green Manuring. Another advantage in the use of the plow 

 is, as has already been mentioned, the turning under of the growth 

 of weeds, grass, and clover as a green manure. Many growers 

 attach considerable importance to this, and some, who have 

 orchards in which winter growth has been killed out by long culti- 

 vation, are seeking for a quickly-growing crop which they can 

 sow with the first rains and secure growth enough to turn under 

 with the winter plowing. This consideration will be farther pre- 

 sented in the chapter on fertilization. 



Plowing Hillside to Prevent Washing. Where the slope of the 

 land is sharp, there is much danger from washing during the rainy 

 season, if the hillside is not terraced or furnished with ditches 

 carefully laid out on contour lines to carry the water down on a 

 gentle grade. The old plan of plowing furrows one above another 

 around the hill to check the flow and let the water down easily, 

 is often found treacherous unless one is able to strike good grades, 



