plant is operated. The liberal use of water will not increase them appreciably; stinted use of water, even though it may fail to produce a profitable crop, cannot materially reduce them, and failure to operate the plant cannot eliminate them from the expenses which the farmer must meet after he has installed his plant. Irrigation water is charged to the land at the rate of $2 per acre foot.

CROP VALUES.

Table 4 shows the price per bushel of grain and price per ton of stover which has been used in determining the value of the various crops under investigation. These figures are furnished by the Kansas State Board of

Agriculture and represent the average price received by the farmer for his crop as reported by more than 2,000 crop reporters for the Board, located in all parts of the state. No figures on milo and kafir are available prior to 1915. For that reason averages for the seven-year period, 1915 to 1921, inclusive, are used in the determination of crop values. An examination of the figures showing the ten-year average for wheat, oats and barley indicates that the seven-year average is probably higher than a normal price; however, it seems to be the most reliable information obtainable.

ANALYSIS OF FACTORS ENTERING INTO THE COST OF

PRODUCTION.

Table 5 shows the various items of expense involved in the production of the several crops. This table shows in detail the charges for interest and taxes on the land, tillage, seed, harvesting, threshing, interest, taxes and depreciation on the irrigation pumping plant, cost of pumping the water used, and the cost for irrigating or distributing the water in the field. In addition to this there is also shown the total cost of producing the crop, the value of the crop, and the net profit.

An examination of these data will show at once a very fundamental principle of the economics of crop production, but one which is too often disregarded when the farmer is attempting to decide on the amount of water he should give the crop; namely, that a considerable portion of the total expense of producing the crop is a fixed charge which bears no relation to the yield of that crop. It is further apparent that this fixed expense does not vary greatly with different kinds of crops. Tillage costs may vary somewhat with the needs of different crops, or with methods calculated to conserve moisture, as, for example, the unirrigated small grains, wheat and barley, where the expense was increased somewhat by double disking the stubble immediately after harvest to create a dust mulch, and in some years cultivating later in the season to kill weed growth; but even this did not materially affect the total cost. Threshing of course, varied with the yield, but that was practically the only item which was not fixed in advance in the case of the unirrigated crop. The cost of pumping the water and distributing it in the field constituted the chief variable expense of the irrigated crops, but if by increasing the water a sufficient increase in yield can be effected, the cost of water becomes an investment instead of an expense. From these data it is evident that with many crops the additional charge for a liberal application of water becomes an exceedingly good investment.

Because of the fact that the yield of dry matter per acre for each inch of irrigation usually decreases as the total amount of water used during the season increases, and perhaps partly as a matter of public policy, many irrigation publications assert that the more water that is given a crop by irrigation the less we get in return per each unit of water applied, and emphasize the folly of using large amounts of water in growing any crop. While the production of dry matter per unit of water does in fact usually decrease as larger amounts of water are applied, the farmer, particularly if he takes this interpretation too literally, can easily conclude that he can afford to apply no more than enough water to allow the crop to mature a very ordinary yield, which might be true if the cost of such water was the only item entering into the production of the crop. Considering, however, that the farmer has set aside one year's use of his land for the production of the crop, has spent considerable labor and money in soil preparation, seed and cultivation, all of which are the same regardless of the yield, and has but to increase or diminish the cost of one item-water-to materially affect the yield and the resulting profit, it is not hard to believe that the stinted use of water may often fail to produce a crop which will pay the fixed charges, while the increased use of water, even though its unit efficiency is not as great, may increase the yield sufficiently to cover all costs and leave a margin of profit.

The problem, of course, does differ depending on whether the water supply is obtained from a gravity system or from an individual pumping plant pumping from wells. In the former case the farmer usually is allotted a predetermined amount of water which he may use as he sees fit, and in the event that the water is more valuable than the land, he may find it more profitable to obtain high yield per unit of water rather than a high yield per acre of land. In the latter case he has made a heavy investment in an irrigation pumping plant upon which he must meet annual charges of interest, taxes and depreciation, regardless of the amount he uses the plant. These items constitute a considerable part of the total cost of pump irrigation. The underground supply from which the water is obtained, for all practical purposes, is adequate, if not unlimited. The chief object in this case is not to produce the greatest yield per unit of water, but to produce a yield sufficient to cover the fixed charges as well as the cost of water, and still leave a margin of profit.

Consulting the data presented, we find that the yield of dry matter per unit of water did in most instances decrease as larger amounts were applied, but we do not find that the amount of water which produced the greatest unit yield produced the greatest net profit.

Milo, for example, produced the greatest unit yield, 2.7 bushels per inch of water, with about 14 inches of water, but the application of this amount left a profit of but $26.48, while 24 inches left a profit of $40.01. Milo is one of the best irrigated crops in western Kansas, but all other crops showed greater net profits (or in the case of unprofitable crops, smaller loss) with amounts of water considerably in excess of the amounts giving the highest unit yields.

Most Kansas farmers have followed the commonly accepted theory with regard to the irrigation of their crops, and have applied only enough water to obtain very ordinary yields, often leaving them no greater profit than the man who does not irrigate. At Garden City, where a power company supplies electricity for pumping to several hundred farmers, an examination shows that less than a half dozen farmers are using power to the extent of more than one dollar per acre annually. This means that the others are using much less than one acre-foot per acre of irrigation water. Many of them obtain yields but little better than their neighbor who farms "dry," and as a result they often doubt, or at least do not appreciate, the value of irrigation. This condition must be corrected.

The problem, therefore, resolves itself into one of showing the relative importance of the various factors entering into the cost of the irrigated crop, and thus encouraging the use of larger amounts of water.

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