176 Importance of Rolling. 



Importance of Eolling Land when Laying Down to 

 Geass.— Grass seeds often fail from the want of moisture close 

 to the surface. This want can be diminished by fine tilth and 

 heavy rolling. Both tend to raise water from below by capillary 

 (from capilla, a hair) attraction. This is explained by the fact 

 that if you immerse a tube of very small bore, and open at both 

 ends, in a vessel of water the water within the tube will rise to a 

 sensible height above the surface of the water in the vessel, and 

 the smaller the tube the higher will the water within it rise. On 

 this well-established principle depends the rising of water 

 through the interstices of the soil, and the smaller these are 

 made by fine tilth, and the compression of the land by rolling, 

 the more freely will water rise to the surface. Per contra, there 

 is hardly any capillary attraction through dust, as the spaces 

 between the particles are too wide, and hence a mulch of dust 

 keeps moisture in the soil — in other words, the moisture being 

 kept further from the surface cannot readily evaporate. A fine 

 surface soil, then, when in a loose state, conserves water by 

 preventing it rising to the surface ; while you have only to roll 

 it if you wish to bring moisture to the surface to aid in the 

 germination of the seed and the support of the young plants 

 which, from lack of moisture, are apt to be starved to death. It 

 is important to note that rolling in warm weather makes land 

 warmer, and in cold weather colder ( Vide Fletcher, " SoUs,'' 

 page 176). 



Eefects of the System in Peeventinq Loss feom 

 Wash. — On August 23rd, 1900, a most severe thunderstorm 

 raged along the Cheviots, inflicting great damage, and especially 

 in the case of turnip fields, where soil and turnips together were 

 in some cases washed right off the land. In the case of the 

 three turnip fields at Olifton-on-Bowmont, one of which received 

 the water from a steep hard hiU. above, there was no loss. In the 

 latter case no muddy water left the field. It was aU absorbed in 

 consequence of the decaying turf, and deca3dng roots of the 

 deeply-rooting plants, which acted as channels to let the water 

 quickly down into the land, and it rose in the shape of clear water 

 at the foot of the field, running out under the gate for several 

 days. The Harewells field in 1903 — a very wet year — showed 

 the same results as regards the absence of wash. 



