348 MAIZE 



CHAP. 299. Conservation of Moisture by Tillage. — South African 



VI11 ' maize-growers in the drier districts have often experienced loss 

 of their crops, and have had to plant twice or thrice because 

 the stands have "burned off" in a long drought following a 

 good spring rain. Such loss may often be prevented — or 

 greatly reduced — by good tillage. After a rain or after 

 irrigation the surface of the soil is packed tight and a " crust" 

 is formed. Through this crust capillary action is set up, and, 

 as the water evaporates from the surface, more is drawn up 

 from below, until the soil is dried out to a considerable depth. 

 But if that crust is finely broken up, capillary action cannot 

 take place ; the fine soil on top forms a " mulch," evaporation 

 is checked, and the soil moisture is left for the young plants 

 instead of being drawn into the air. 



300. Dry-land Farming. — By the conservation of soil-mois- 

 ture, through the adoption of better tillage, it is probable that 

 maize-growing may be extended considerably beyond the pre- 

 sent western limits of the South African Maize-belt; just how 

 far, has yet to be determined, but the practice of dry-farming 

 methods would undoubtedly add greatly to the area at present 

 under crop. Jethro Tull (l) says: — 



" The well hoed earth, being open, receives and retains the 

 dews ; the benign solar influence is sufficient to put them in 

 motion, but not to exhale them from thence. The hoe pre- 

 vents the [growth of] turf, which would otherwise by its blades 

 or roots intercept and return back the dews into the atmos- 

 phere, with the assistance of a moderate heat. So that this 

 husbandly [i.e. dry-farming] secures Luserne from the injury 

 of a wet summer, and also causes the rain-water to sink down 

 more speedily, and disperse its riches all the way of its passage ; 

 otherwise the water would be more apt to stand on the surface, 

 chill the earth, and keep off the sun and air from drying it: 

 for, when the surface is dry and open, Luserne will bear a very 

 great degree of heat, or grow with a mean one." 



301. Irrigation. — Irrigation, also, might extend the area 

 now planted to maize. But irrigated land is too valuable to 

 be devoted to this crop except in the vicinity of good markets, 

 where early "green mielies," for table use, command a suffi- 

 ciently high price, or where climatic conditions do not permit 

 maize to be grown otherwise ; and then only if the cost of 

 importation exceeds the local value of the crop. 



