272 



THE IKKIGATION AGE. 



IRRIGATION EXPERIMENTS IN ARIZONA. 



Investigations Covering a Period of Four Years at the Experi- 

 ment Station Farm at Tucson. 



BY PROF. ALFRED J. ll'CLATCHIE, 



Agriculturist and Horticulturist of the Arizona Agricultural Experiment 

 Station. 



previous to plowing the land for the reception of the 

 seed. This amount was usually about .6 of a foot. 

 To be sure, much of it would be lost before the crop 

 would be sufficiently developed to begin to use it, but 

 this irrigation previous to plowing is in most cases a 

 necessary part of our farming operations, and the water 

 thus used should be counted as part of that necessary 

 for producing any given crop. 



The atmospheric conditions seemed to be unfavor- 

 able for the proper development of many crops during 

 the spring of 1900, causing low yields, regardless of the 

 amount of water applied. Hence many of the yields 

 (especially of vegetables) can not be considered indica- 

 tive of what the same amount of water would produce 

 during an average season. 



RECORD FOE 1901. 



In addition to keeping a record of the water ap- 

 plied during the growing of a crop, a record was made 

 of the amount applied previous to planting the crop. 

 In some cases, as of melons and corn, part of this 

 amount is applied previous to plowing and part of it 

 after plowing, a short time before planting the seed. 

 As w*s noted in the case of the previous year, two of 

 the grain crops were sown during the previous year. 



From a record kept of the work done on each crop, 

 and from data secured from farmers, an estimate, be- 

 lieved to be fairly accurate, was made of the cost of the 

 production of each crop grown during 1901. 



The gross value of the crop per acre was estimated 

 chiefly from a record of actual returns from produce 

 sold. In case a crop, or a portion thereof, was not sold, 

 it was credited with what it would have brought upon 

 the market at the time it was harvested. 



It will be observed that some crops give a much 

 higher net return per acre foot of water applied than 

 others. This is a matter of considerable importance to 

 a water user. It is to his interest to obtain as large a 

 net return from his investment in water as possible. 

 It is to his interest to grow, to the extent the market 

 will warrant, the crops that will give him the greatest 

 net return for the water used. If potatoes, or toma- 

 toes, or melons give a higher net return annually than 

 In the above table, there is included in the amount grain, then to grow one of the above instead of grain 



[Continued.] 



A record has been kept of the water applied to the 

 principal crops grown upon the station farm during 

 1900 and 1901. For determining the amount applied 

 at each irrigation, gauged flumes were installed at neces- 

 sary points upon the farm, and the length of time 

 water ran upon a given crop at each irrigation, and 

 the depth in the box, noted and recorded by the employe 

 doing the irrigating. From the records thus made are 

 computed the amounts applied to the crop. During 

 1900 no attempt was made to ascertain the cost of pro- 

 duction and the gross value of the crop, as was done 

 during 1901. 



RECORD FOR 1900. 



Three of the crops harvested during this year were 

 sown during November and December of 1899. Most 

 grain sowing is done during the above months, but the 

 planting of beets during that period is unusual. Had 

 cold rainy weather followed the sowing of the beets, 

 they would not have fared so well. 



TABLE V. CROP RECORD FOR 1900. 



of water applied to produce the crop the water applied 



FIG. 2. IRRIGATING YOUNG POTATOES THROUGH FURROWS. 



would be a good business policy. 



It is also important that such a 

 M variety of crops be raised as will result 

 in using the water available, at all 

 times of the year. Grain requires wa- 

 ter during one part of the year, pota- 

 toes during another, melons during a 

 later portion, and corn and some other 

 crops during still later parts of the 

 year. Diversified farming is likely to 

 result not only in using the water 

 throughout all the year, but in higher 

 net returns from the water used. 



The individual farmer is interest- 

 ed in the net returns he obtains, but 

 the community is equally interested in 

 the gross returns from a crop. A 

 large gross return ordinarily indicates 

 that a large proportion has been of ne- 

 cessity spent for labor. A crop that 

 furnished labor for a large number 

 of workmen is a more valuable one 

 to a community than one grown with 

 little labor. The more laborers re- 

 quired at farming operations, the 



