THE IRRIGATION AGE. 



301 



ARID AGRICULTURE 



BY 

 B. C. BUFFUM, M. S. 



Manager of the Wyoming Plant and Seed Breeding Company, Wor- 



land. Former Professor of Agriculture in the University of 



Wyoming and the Colorado Agricultural College, and 



Director of the Wyoming Agricultural 



Experiment Station. 



PLOWING. 



The plow has eyoluted from a crude war-club, which was 

 put to use for tilling the soil and afterward became the first 

 letter of the alphabet. 



"Stirring and mixing the soil is the fundamental labor of 

 agriculture." (Roberts.) Plowing is the foundation upon 

 which the structure of farming is built. It is the matter of 

 first concern to the farmer. Plowing seems to be a simple 

 and easy process, but both the science of the why and the art 

 of the how, are deep subjects. The character of his plowing 

 displays the knowledge of the dry farmer and underlies his 

 success. 



With hardly an exception the recommendation to the dry 

 farmer is to plow deep. Ordinarily this means to plow as 

 deep as possible which will generally be from seven to ten 

 inches. This first commandment for dry farming is prob- 

 ably the one most often broken. It is not always possible to 

 plow deep. The soil may be hard. The farmer more often 

 does not have sufficient power to pull his plow. A common 

 condition on western farms is small horses, few of them 

 and lack of that care which gets the most out of a horse. 

 Sometimes the right kind of plows are not at hand or are 

 not kept in best condition. 



The first reason we plow deep is to make a large enough 

 reservoir to absorb and hold the moisture. Our soils have 

 been pounded down for centuries by the patter of rains and 

 the feet of animals. They are too compact and have perhaps 

 never been wet to a depth of more than a few inches. When 

 in tilth some of these soils will absorb over 40 per cent of 

 their weight of water. If they contain from 8 per cent to 20 

 per cent of moisture they are in condition to support grow- 

 ing crops. A crop of oats at Laramie did not wilt for some 

 days when the soil contained as little as 3 per cent of 

 moisture. 



How the storage capacity of a soil may be increased by 

 deep plowing may be illustrated by a few figures. A soil 

 weighing one ton per cubic yard, weighs approximately 1,613 

 tons per acre taken one foot deep. If such a soil will absorb 

 and hold 20 per cent moisture and is plowed six inches deep, 

 it will take up 161.3 tons of moisture per acre. A rainfall of 

 1.4 inches will supply this amount of moisture and fill up our 

 six-inch reservoir. If the ground is plowed only three inches 

 deep, and the sub-soil is hard, it would not be able to store 

 a rainfall of more than seven-tenths of an inch and should 

 more water fall at one time it will be lost and may wash 

 the soil away with it. If plowed nine inches deep and put 

 in good condition, such a soil reservoir would absorb and 

 hold over two inches- of rainfall at one time. A soil already 

 containing a considerable water would be filled up with less 

 rain, and deep plowing would be still more important. 



Deep plowing is usually good plowing in that it grinds 

 up and pulverizes the soil. Soils that are plowed deep come 

 more rapidly into good tilth. Fining the soil particles re- 

 leases and makes available plant food. It lets in warmth and 

 air and gives better chance for the activity of chemical agents 

 and bacteria. 



The larger part of soluble plant food becomes available 

 in the surface soil. Plant roots pass through it easily and 

 here they send out their feeders to make use of the foods 

 ready for them. If four- inches of trie surface soil is kept 

 stirred for mulch the difference between plowing seven 

 inches deep and eight inches deep equals twenty-five per cent 

 in the area of the surface soil upon which the roots feed. 



Where the soils are light and winds drift them, shallow 

 plowing may result in all the top soil, down to the sole of 

 the furrow being blown away. Deep plowing, on the con- 

 trary, throws up heavier and rougher furrows, and tends to 

 anchor the soil in place. Plowing deep, therefore, both pre- 

 vents washing and drifting. 



Where soils are heavy, it often happens that only an inch 

 or two of the surface is in condition for the growth of plants. 

 Turning this surface soil under and covering it deeply with 

 cold, untamed and unproductive clay, may prevent raising a 

 good crop for longer time than it is desirable to wait. This 

 seldom occurs in dry farming, for the summer fallow will 

 tend to put the soil into tilth before the first crop is planted. 

 Some soils may be so shallow that it is not well to plow 

 them deep. Where irrigation is practiced in some of our 

 drier regions where the soil is very poor in vegetable matter, 

 merely discing two or three inches of the surface often gives 

 a better first crop of grain than plowing. Such soils must 

 be irrigated often and carefully because the soil may wash 

 and the area for storage of moisture is so small that it dries 

 out quickly. Generally a soil that is suitable for dry farming 

 is one which may be plowed deeply. 



Subsoiling is done by using a 3igger which follows the 

 plow and tears up a few inches of the furrow sole or by 

 means of a mole plow which is run underneath the furrow 

 and lifts and breaks up the subsoil to the depth of fifteen 

 inches or eighteen inches. It is expensive to prepare ground 

 by subsoiling and is not recommended for general practice. 

 Our rainfall is so small that so large a reservoir is not needed 

 for storage of moisture and where irrigation is practiced 

 there seems no advantage from filling so much loose soil with 

 water at one time. There are places where subsoiling is ad- 

 visable, and it often proves profitable for root crops or prep- 

 aration of land for tree planting. 



The second time the soil is turned, plow about two inches 

 shallower than the first plowing. This is to avoid turning 

 up the undecomposed sod. In our dry climate it ordinarily 

 takes more than one year to incorporate any vegetable mat- 

 ter plowed under, with the soil. Crops plowed under when 

 green, or well rotted manure, will become humus much more 

 rapidly than will dried-out materials. Sometimes it is best 

 to back-set the land by turning the furrows the same direc- 

 tion as the first plowing. If the land is in good condition, 

 cross-plowing will do more to pulverize and make a good 

 seed bed. It is economy to make the lands as long as possi- 

 ble to avoid much turning at the corners _and tramping. If a 

 soil is plowed year after year at the same depth the sole 

 of the furrow becomes packed and hardened by the smooth- 

 ing action of the plow bottom, and by the tramping of the 

 horses. This may bring good results sometimes when irriga 4 - 

 tion is practiced, but in dry farming, doing alternate plow- 

 ings at dofferent depths, tends to break up the furrow sole 

 and allow movement of moisture to and from the subsoil. 



Good plowing is the kind that gives the best results in 

 the crop. What good plowing is, depends on conditions, but 

 the work should be well done. Poor work always leaves its 

 mark and the mark is always a minus sign when its result 

 reaches the pocketbook. Good plowing may be defined as the 

 smooth, even furrow so turned that the soil moved, sets 

 more or less on edge with few and small air spaces under- 

 neath, and with the furrow slice crushed and pulverized as 

 much as possible. There should be no skips and the cut 

 and cover method is absent. To do good plowing the furrow 

 should be cut no wider than the plow-share, and to be on 

 the safe side good farmers cut an inch or two narrower than 

 the lays properly shaped. A factor in good plowing is to do 

 the work when the soil is in the right condition. This will 

 differ on every farm. Heavy clay soils must not be plowed 

 too wet. There is little danger of working our more sandy 

 soils when wet. Western soils may be plowed when quite 

 dry and left in condition to absorb the first rains or melt- 

 ing snow. The lime in them insures flocculation and there 

 is little danger of dry puddling. 



Late fall or early spring plowing is practiced to absorb 

 moisture. In some parts of the West, where the rainfall 

 comes mainly in the winter season, the soils may get so hard 

 and dry that until the rains come it is not possible to plow 

 them in the fall. Where the rainfall comes in the spring and 

 summer the soils are usually in such condition that they may 

 be plowed in the fall, though they are sometimes very dry. _ A 

 comparatively new practice is to disc the sod or stubble im- 

 mediately after a crop is harvested to save the moisture and 

 keep the soils in condition to be fall plowed. The spring 

 season is usually the most busy one and especially is this so 

 at high altitudes where the spring work must be done in a 

 very short time. Having the plowing out of the way by 

 doing it in the fall, enables the farmer to get his crop in 



(Continued on page 333.) 



