186 One Thousand Questions in Agriculture 



where trees that have been allowed to become dormant too early in 

 the season and have been weakened by a long period of soil-drought 

 during the autumn, have cast their blossoms or manifested other 

 indications of weakness during the following year. It is thoroughly 

 rational to apply irrigation to hold the leaves and secure their service 

 in the strengthening of bloom buds for the following year by irriga- 

 tion. Such irrigation should be applied immediately after the fruit 

 is gathered or even before that, if the yellowing of the leaves in- 

 dicates lack of strength in the tree and the frequency and amount of 

 irrigation during the autumn depends upon whether the soil will 

 hold moisture enough to carry the tree to its proper period of dor- 

 mancy. This may be determined by the aspect of the trees and 

 by digging down two or three feet to see whether the soil carries 

 moisture which is likely to be sufficient until the coming of the 

 rains. Whether late irrigation will be necessary is also determinable 

 by the character of the soil; on close retentive soil it may not be 

 necessary, while on loose, sandy or gravelly soil it may be essential 

 to the life of the tree. One has to settle all these matters by judg- 

 ment and not by recipe. 



Fertilizers in Irrigation Water. 



Do yoii recommend putting fertilisers in irrigating water? I am 

 about to water the orchard and am thinking of putting some nitrate in 

 the water. 



You can distribute any soluble fertilizer by dissolving it in irri- 

 gation water, but few have ever done it because of the difficulties of 

 getting equal strength in running water. It is much easier to dis- 

 tribute on land before irrigation. 



Irrigating Alfalfa on Heavy Soils, 



Hozv does alfalfa succeed on adobe and soils slightly modified from 

 it? Does irrigation ivork well on adobe planted to alfalfa? 



If you get the irrigation adjusted so that the soil shall not be 

 water-logged and so that the water does not stand on the surface 

 when the sun is hot, you can get plenty of good alfalfa on a heavy 

 soil. Irrigation on adobe soils must be done more frequently and 

 a less amount at each application to guard against the dangers 

 named above. 



How Much Water for Crops? 



Some of my land is heavy, but the most of it is light soil. I want 

 alfalfa mostly, some potatoes and grain, and later oranges, olives and 

 other fruit. How much water in inches or acre feet is required per acre 

 per year for the irrigation of it? 



The amount of water required to grow dififerent crops depends 

 upon the crop itself, upon the time of the year in which it grows, 

 the character of the soil, etc. There is no such thing as stating 

 how much water would be used for all crops on all soils, and at all 



