OCR Text |
Show MULCHING THE SOIL TO SAVE MOISTURE Covering Must Be the Kind That Will Not Blow Away. Dust and Straw, Except in Orchards or Berry Patches, Not Satisfactory; Satisfac-tory; Water Will Evaporate Evapor-ate Quickly. (Prpared by the United Statea Department ot Agriculture.) Thirty years of investigation by the United States Department of Agriculture Agricul-ture and the much longer experience of practical farmers have demonstrated demonstrat-ed that about the only way of conserving con-serving soil moisture for the use of agricultural plants in the regions ot scanty rainfall Is to provide a suitable seed-bed for their germination and early growth and to prevent useless weeds that would otherwise compete with them. Theoretically, covering or mulching the soil for the purpose of preventing the loss of soil moisture is very efficient; practically, it has very narrow limitations. There arc several things required of a soil covering or mulch besides simply preventing the loss of moisture. mois-ture. Among these may be mentioned the following: It must "stay put" ; that is to say, it must be of such character charac-ter that it will not be blown away by the high winds common to all arid regions. re-gions. This rules out all dust and straw mulches, except possibly in orchards or-chards or berry patches, and, in them, the straw mulch is frequently objectionable objec-tionable on account of Its harboring rodents, especially field mice. A soil covering must let rain into the soil. This rules out the dust mulch which Is almost, if not quite. Impervious to ordinary rainfall, as it puddles producing pro-ducing a sheet of paste over the surface sur-face that prevents thk water from reaching the roots of the crop plants. A straw mulch, If thick enough to prevent the growth of weeds, will absorb ab-sorb most, if not all, of an ordinary rainfall. The water thus absorbed will evaporate very quickly, as soon as the rain ceases and the sun begins to shine on the mulch, never reaching the roots of the crop plants. The heating of the soil by the sun's rays and its aeration by exposure to the winds are important factors in the growth of agricultural crops. Many wild woods and swamp plants thrive without these conditions, hut nearly all of our agricultural plants have been developed through long periods of time in soil open to the free access of the sun and the wind, and these conditions seem to have become be-come necessary to their fullest development. |