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Show CRUST UNDER MULCH Nothing Can Prevent Formation if Drouth Lasts Long. Cannot Bo Broken Up Without De-itroylng De-itroylng Crop, but Can Be Rendered Ren-dered Harmless by Right Kind of Plowing. Every dry year some one asks: Wbat can we do when a crust forms under mulch? Nothing can prevent this crust forming If the drouth lasts long enough, writes E. R. Parsons In Dry farming Bulletin. The top inch of the mulch dries first, then the second, then the third, and 'then the Inevitable crust begins to form underneath and becomes thicker and thicker with every day of drouth. We cannot break up this crust without with-out destroying the crop, but we can render this crust perfectly harmless by the right kind of plowing, and that is all that Is necessary. The formation of this crust depends cn two different factors, the drouth about and the moisture conditions below. be-low. People sometimes talk and write In magazhies about the dry farmer making mak-ing a cistern for moisture and putting the lid on and so forth, as if he had all the water he could handle, but the fact of the matter Is we can wet up our land by conserving moisture to a certain percentage to a certain limit only, which is determined by the capillarity cap-illarity of the soil in question, and above that limit, which is more or lees constant, it Is Impossible to raise It as long as there Is a dry subsoil below, which Is the true condition of the dry farm soil. What I mean is this: When a storm comes the water goes down by capillarity or gravity, or both combined, until It Is too diffused to go any further; capillarity ceases for the time being until another storm comes and starts It again; then it goes down again until It stops for lack of water. Now, if we make a test of this soil for moisture a day or so after storm, when capillarity has ceased working, we find we have no more moisture In the soil than we had before, be-fore, the percentage is the same, but It has gone down further. We are obtaining ob-taining a greater depth of moist ground. Some farmers plow shallow, owing to a misconception of this action of moisture. They expect the moisture to rise by capillarity to moisten their crust and hold the drouth at bay, when capillarity is already exhausted by the downward pull of gravity. After making several hundred tests In all varieties of soil during the last 30 years, I have been unwillingly forced to the Inevitable conclusion that capillarity as a help to the dry farmer is bringing up moisture from the subsoil to the roots of his crops Is a negligible quantity on true dry farm land that Is not sub-Irrigated. We all allow, however, that capillarity capillar-ity works very strongly sometimes for a few days on the top three or four Inches after wet weather, before the moisture has diffused downward, and we can make use of this knowledge for seed germination, by using the press drirr, which will draw the moisture mois-ture to the packed seed rows, without with-out packing and baking the whole flp'.d. Since the moisture does not rise to moisten our crust except very slightly slight-ly by distillation. It Is clear that the best thing we can do Is to go down after the moisture. The only way to do this Is to plow deeply, not any six or seven Inches, but eight, nine, ten or twelve. |