Arizona sentinel and Yuma weekly examiner., 1914-04-23
COTTON FERTILIZERS IN ARIZONA

To farmer asking about fertilizers
 for cotton, Prof. Stanley F. Morse
 Agriculturist of the Arizona Agricul
 tural Experiment Station, writes:
 Answering your letter inquiring what fertilizer would be best adapted to sandy soil for cotton, wish to say that if your soil is not in proper to sandy soil for cotton, no amount of chemical fertilizer will ever make 1t so. I am familiar with your soils and find that they need just two things:
 1. Organic matter or humus, which can best be supplied by applying cor
 ral manure, straw from lold straw stacks, or by turning under a green crop, such as sour clover, Canada field peas, Colorado stock peas, or even a small grain like wheat or barley.
 2. Nitrogen, which can be best sup piled by the use of most of the fore going materials and through cultiva- tion of soil. You can buy nitro gen in the commercial form, but 1t will not be effective unless there is an abundance of humus in the soil.
 Allow me to say that the introduc- tion of commercial fertilizers to Ari- zona at the present time would be a calamity. Our soils are, for the most part, virgin, and invariably rich in both the essential elements of phos- phorous and potash, while lacking in humus and nitrogen as already men toned. Our crops should be grown in a rotation that will furnish the essential nitrogen and humus. By using alfalfa, sour clover, Canada field peas, Colorado stock peas, beans anc peanuts, or COW peas in a rotation of from two to ten years in length the fertility of our soils can be kept up and commercial fertilizers will not be needed probably for hundred years at least. Commercial fertilizers which are expensive in the first place. freouently result in an increased yield the first year or two in soils fairly well suppied with humus; after that the humus becomes burned out and the crop yields become absolutely unprof- table, yet the farmer having once se- cured good yields from commercial fertilizers, continues to use them ID the hope that their beneficial effects will zecome apparent again.
 It usually has been the experience that wherever commercial fertilizers have been used, the farmer has had to mortgage his crop in order to pay for them; this has resulted in the custom that in many cases has kept the farmer poor and made the soil in- fertile, as already explained. If you. land is not in shape to grow cotton, then do not grow cotton until you have put your land in condition Fby adding humus and nitrogen, as already suggested. One other thing about commercial fertilizers: In the list of fertilizers which you sent me, every fertilizer offered contains not only nitrogen, which might be of some value, but also potash and phospho, ous; now since phosphorous and pot ash are in super-abundance in our Arizona soils, why should we pay out many hundreds of thousands of dol lars to buy these materials which are shipped from several thousand miles away. And why should we buy the nitrogen when four-fifths of the air which circulates above our farms con- tafns millions of pounds of this essen tial element which we can secure at will by growing alfalfa, clover, peas and other legumes, and by cultivating the soil to stimulate the living bac- terial therein which also have the power to secure nitrogen from the air and add it to the soil? We must not use commercial fertilizers yet in Ari- zona. Grow cotton in a rotation with Iegumes and other cropes.