1905 



FORESTRY AND IRRIGATION 



375 



gages, thermometers, anemometers, 

 etc. 



Investigations in this line have been 

 carried on for two years and have em- 

 braced the following experiments : To 

 determine the rate and amount of 

 evaporation from water surfaces such 

 as from irrigation checks, canals, and 

 reservoirs, and the influence exerted 

 by such factors as temperature, wind, 

 altitude, and humidity. In like man- 

 ner an effort has been made to deter- 

 mine the evaporation from the sur- 

 face of typical soils and to ascertain 

 and compare the loss from this cause 

 on soils that are irrigated in each one 

 of the standard methods. 



In an experiment which had for its 

 objects the determination of the loss 

 by evaporation from soils containing 

 different amounts of moisture, the 

 difference was so great that it was de- 

 cided to take up the question of soil 

 mulches of different depths varying 

 from zero to 12 inches. Various crops 

 have also been grown within tanks 

 under field conditions to determine the 

 actual quantity of water required by 

 each for vigorous growth and in the 

 same connection to ascertain, if possi- 

 ble, the transpiration of different 

 plants and the relation between the 

 amcrnt of water evaporated from the 

 foliage of plants and that lost by evap- 

 oration from the surface of the adja- 

 cent soil. 



A little thought will convince any- 

 one familiar with irrigation that these 

 subjects which have never been con- 

 sidered by the cultivators of the old 

 irrigated regions of Europe and Asia 

 and which have but recently begun to 

 attract the attention of western farm- 

 ers lie at the very foundation of irri- 

 gation practice and until more accu- 

 rate information is obtained concern- 

 ing them the irrigator cannot be cer- 

 tain that he is watering his crop in the 

 right way or at the right time. 



THE IRRIGATION OF CITRUS ORCHARDS 

 NEAR RIVERSIDE, CAL. 



The successful production of 

 oranges represents, it is believed, the 

 highest type of the husbandman's art. 



As a corollary to this fact it may be 

 stated that in no other part of the 

 civilized world is there to be found 

 more intelligent farmers than dwell 

 amidst the orange groves of southern 

 California. A high order of intelli- 

 gence is required in order to succeed. 

 In the first place suitable land on 

 which oranges can be grown is high- 

 priced, and water extremely scarce 

 and valuable. In addition to these 

 there is the cost of cultivation, irriga- 

 tion, pruning, spraying, picking, pack- 

 ing, and marketing, all of which 

 amount to a large sum per acre. The 

 cost of production being so high there 

 is need of skillful management and 

 the closest kind of economy. 



The main purpose of our investiga- 

 tions is to lessen the waste of water 

 applied to citrus orchards and thus re- 

 duce the annual cost of the water bill. 

 In order to accomplish this purpose it 

 was necessary first to study in a gen- 

 eral way the growth and root develop- 

 ment of citrus trees, the depth and 

 character of the soil, frequency of ir- 

 rigation, quantity applied at each wa- 

 tering, mode of cultivation, and the 

 like. In addition to these, a compari- 

 son is being made between the effects 

 of shallow and deep furrows, and the 

 rate of percolation from each. By 

 means of borings and the taking of 

 soil samples at different depths some 

 knowledge is obtained of the distri- 

 bution of water in the soil and the 

 probable amount lost by evaporation 

 from the surface. In the end, we hope 

 to be able to give a partial answer to 

 the irrigator's question, "what be- 

 comes of the water which is spread 

 over my orchard during an irriga- 

 tion ?" 



STUDIES OF METHODS OF PREPARING 

 LAND AND APPLYING WATER. 



During the past two years the dif- 

 ferent ways of preparing land to re- 

 ceive water and the most common 

 methods of applying it have been stud- 

 ied. The results of these studies have 

 IHVII something of a revelation in that 

 it has shown that this branch consti- 

 tutes in many cases the big half of the 



