4 DRY LAND FARMING 



along between areas where the precipitation is so short 

 that man cannot secure profitable production therefrom in 

 the absence of irrigation, and where he can secure the 

 same, notwithstanding the shortage in the precipitation. 

 This border line is not alone determined by the amount 

 of precipitation, but also by the season when it comes 

 and by the soil, subsoil and climate. The precipitation 

 that forms this dividing line, therefore, cannot be stated 

 precisely in inches, as it will vary with the conditions. 

 It is not far, however, from 8 to 10 inches. 



Where dry farm methods are practised, the precip- 

 itation is usually so ,short that special methods of culti- 

 vation are necessary in order to produce good crops. 

 But some seasons it may be enough to grow such crops 

 without resorting to these methods. Since it cannot be 

 known beforehand when such seasons will come, the 

 land in those areas shoulql be tilled every season with 

 a view to meet the exigencies of a dry season the follow- 

 ing year should it come. Even though it should ^not come 

 the labor thus expended will not be lost, because of the 

 helpful influence that such careful handling of the soil 

 will have on the production. The amount of the pre- 

 cipitation that will make production profitable cannot be 

 stated definitely in inches, as it will vary from the same 

 causes that lead to variation under arid conditions. Good 

 crops can be grown almost any season where the normal 

 precipitation runs, say, 10 to 15 inches. These figures, 

 however, are not given as the minimum or maximum of 

 the precipitation called for as essential to the growth of 

 crops in semi-arid areas. 



While the practise of dry fanning methods has, until 

 the recent past, been confined wholly or almost wholly 

 to areas where the normal precipitation is more or less 

 deficient for the best needs of the crops every year, it 

 is now coming to be practised in modified form in areas 

 where the annual precipitation is enough or more than 



