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plants which minister to the needs of human kind have been im- 

 proved by tillage. To plow, cultivate, or hoe, to turn and stir the 

 soil, and so improve the crop, or so improve the soil, these simple 

 operations were the beginnings of agriculture and the beginnings of 

 civilization and they have been the chief tasks of all civilized peo- 

 ples. Tillage is so universal, and is so essential a part of agricul- 

 ture that those who oppose it for any domesticated plant should 

 look well to its origin, to its history and to its present place in agri- 

 culture before charging it with evil. 



There are two words to define in the compound word sod- 

 mulch. Sod is soil made compact and held together by the matted 

 roots of living grass. A mulch is an organic material placed about 

 trees to prevent evaporation and to furnish humus. The sod-mulch 

 advocates divide into several sects in their manner of making use 

 of sod and mulch. One sect keeps sheep on the sod, another pigs, 

 and still another says the grass is not sufficient and must be supple- 

 mented with straw or manure. 



We can understand the experiment to l)e discussed better if we 

 take a brief glance at the philosophy of tillage and that of sod-mulch. 

 The objects of tillage are so well set forth by one of the leading 

 living authorities on the subject, Professor F. H. King, that I give 

 them without a change of a single word. 



" (i) To secure a thorough surface uniformity of the field, 

 so that an equally vigorous growth may take place over the entire 

 area. 



(2) To develop and maintain a large efi^ective depth of soil, 

 so that there shall be ample living room, an extensive feeding surface 

 and large storage capacity for moisture and available plant-food 

 materials. 



" (3) To increase the humus of the soil through a deep and 

 extensive incorporation of organic matter so that there may be a 

 strong growth of soil micro-organisms and the maintenance of a 

 high content of water-soluble plant-food materials. 



" (4) To improve the tilth and maintain the best structural con- 

 dition in the soil, so that the roots of the crop and the soil organism 

 may spread readily and widely to place themselves in the closest 

 contact with the largest amount of food materials. 



" (5) To control the amount, to regulate the movement, and to 

 determine the availability of soil-moisture, so that there shall never 

 be an excess or deficiency of this indispensible carrier of food ma- 

 terials and through the plant. 



" (6) To determine the amount, movement and availability 

 of the water-soluble plant-food materials present in the soil, so that 

 growth may be both rapid, normal and continuous to the end of 

 the season. 



(7) To convert the entire root zone of the soil into a com- 

 modious, sanitary living and feeding place, perfectly adapted to the 

 needs of the roots of the crop and to the soil organisms, — adequate- 

 ly drained, perfectly ventilated and sufficiently warm. 



