HOW AND WHEN TO IRRIGATE. 



BY F. C. BARKER, NEW MEXICO. 



HOW and when to irrigate will depend 

 so entirely upon soil, climate, 

 weather, crops and many other varying 

 circumstances, that no hard and fast hues 

 can be laid down. 



Take for instance the first question of 

 whether we shall irrigate by small furrows, 

 as in California, or on the moat by the 

 flooding system. I maintain that it all 

 depends upon whether the soil is porous 

 and soaks laterally or whether the soil 

 is the reverse, as it is where I live. 

 Furthermore, the furrow system will suit 

 certain crops while it will not do for 

 others. The best system can only be 

 found out by experience in each locality. 

 Then, as regards the frequency with which 

 crops should be irrigated. I venture to 

 say that no one can fix this by any given 

 number of days. Different crops require 

 different treatment, and even the same 

 crop will need more or less water accord- 

 ing to the conditions of soil, weather and 

 climate. The only rule one can lay down 

 is that no crap needs water so long as the 

 soil about the small roots nearest the 

 surface is wet enough to roll up into a 

 ball; but the moment any of these small 

 roots are in dry earth the plant or tree is 

 sure to suffer. 



Serious harm has been done to many 

 orchards whose owners read in books or 

 papers that in California they did not 

 irrigate during winter, and accordingly 

 applied the rule to land which received 

 little or no rainfall in the winter, quite 

 forgetting that the reason why they do 

 not irrigate during winter in California 

 is that that is their rainy season. 



I have sometimes been amused by read- 

 ing calculations of how many inches of 

 water are needed for irrigation. Some 

 writers have made a regular formula, as 

 though it were an engineering problem, 

 and, having arrived at the exact number of 

 inches required by a crop, deduct the 



natural rainfall and think they have 

 the whole question settled. Now, in the 

 first place, the rain may come when it is- 

 not needed, and again it often falls in such 

 small quantities at a time that it rapidly 

 evaporates and thus does very little to- 

 ward assisting irrigation. 



No one can farm successfully with 

 irrigation any more than without it who 

 does not understand plant life sufficiently 

 well to know when water is needed by a 

 tree or plant. It requires experience like 

 every other branch of farming. The in- 

 experienced man may make a failure by 

 not giving enough water to keep the roots- 

 moist right down to the bottom, or he 

 may, and frequently does fail through 

 giving so much water that the soil becomes- 

 waterlogged and deprived of air; but a 

 still more frequent cause of failure is the- 

 omission to cultivate the surface of the soil 

 after each irrigation. It is only by actual 

 experience gained in each locality that 

 the farmer can learn how and when to 

 irrigate. 



Fertilizers for Potatoes. Like 

 all other farm products, potatoes yield in 

 proportion to the soil in which they are 

 grown. To have a good crop, the land 

 must be reasonably good, and to maintain 

 its fertility the soil must be fed by some- 

 means. 



If barnyard manure is used, it should 

 not be coarse, or it will do more damage 

 than good, in burning the vines. And, 

 again, it must not be hauled out in the 

 spring and only partially plowed under. 

 The manure should be rotted sufficiently to 

 be thoroughly incorporated in the soil, 

 and be hauled out in the winter or early 

 spring and plowed under, deep. 



Potash and phosphoric acid are the- 

 principal elements of plant growth needed, 

 and in many cases these can be supplied 

 to a better advantage by purchasing and 

 using commercial fertilizers than in any 

 other way; because they contain a good 

 percent of potash. Wood ashes can often 



