Campbell's 1902 Soil Culture Manual. 



19 



is gotten into the ground. After we have succeeded in storing a large 

 quantity of water down in the soil to a depth of four, six, or possibly ten 

 feet, the sub-packing, or thorough firming of the lower portion of the fur- 

 row slice, is very important, for when our crops reach the long, dry peri- 

 ods of extreme heat, such as was experienced in mid-summer of 1901, we 

 are in position to feed the plant all the moisture it needs and thus prevent 

 any material loss or damage. As shown by Prof. King, in 147 tests, the 

 packing of the lower portion does materially aid the movement of moisture 

 stored in the soil in its upward course to feed the roots. 



We wish to impress upon the mind of the reader quite clearly the 

 importance of doing everything possible to provide an ample amount of 



Cut No. 4. 



available moisture at all times. When we reach a point in the ex- 

 treme heated portion of the last afternoon prior to a heavy rain, 

 where our supply of moisture is beginning to shorten, the fact that we 

 have by this sub-surface packing been able to lift the water stored below 

 a little faster may save our crop. 



In cut No. 4, we represent the cross-section of a lateral or branch 

 root very largely magnified. The little branches running out from the 

 center represent the little hair roots, or feeders, which are often so small 

 that they are scarcely perceptible to the naked eye. These little feeders 

 are nothing more nor less than little tubes, or elongated cells. You will 

 notice in the outer tier of cells each little feeder practically forms a part of 

 the cell. Around this root are four white spots, which represent air 

 spaces. They are, however, extremely small, not larger than the head of 

 a pin; yet, small as they are, you notice how the little feeders turn away 



