TWO METHODS OF FARM IRRIGATION. 249 



steep slopes and washing away valuable land at each irrigation. 

 A farmer near Standerton, who is acting on the advice of the Irri- 

 gation Department, irrigates light sandy soil on a steep slope, and 

 IS getting quite satisfactory results with small furrows taken 

 across the slope. If he attempted to irrigate in the usual way, all 

 his land would soon be washed into the Vaal River. 



For orchard irrigation, this system is probably the best for 

 practical farming. Xo water need ever touch the trunks of the 

 trees, and, by judiciously arranging the furrows, the roots can be 

 induced to spread ; that gives them a greater mass of soil from 

 which to draw nourishment. After irrigating, cultivation should 

 •start as soon as ever the surface is dry enough. I am not dealing 

 with fruit-growing, but I may add that, in the best orchards in 

 America, cultivation is continued without intermission until the 

 trees again require water. 



This method of irrigation can be used for anything, but lucerne, 

 etc., tend to choke the furrows after getting a good growth. When 

 that happens a larger flow of water is required. There is nothing 

 to prevent you from dividing your lands by small banks into strips 

 10 to 15 feet wide and flooding when the crop is thick. In this 

 way crops can be grown on slopes so steep that they could not 

 stand flooding until the ground was covered with a thick growth 

 »of vegetation. 



CONCLUSION. 



The condition of the sub-soil is a highly important point that 

 requires careful attention, no matter what system of irrigation may 

 be employed. I think that I am correct in saying that most irri- 

 gators in South Africa water tTieir lands too frequently. Most of 

 them seem to think that the great thing is to eet the lands wet 

 enough to plough, and wet enough for the seeds to germinate and 

 sprout. In a few days they begin to wilt and the farmer thinks 

 they need more water. So they do, no doubt ; but thev would not, 

 if he irrigated properly. However, they need water, he irrigates, 

 the young plants brighten up, and in a few days thev wilt again. 

 W'ell, they must have water, so he irrigates again, and the same 

 performance is repeated a'bout once every week or ten days. \\'hen 

 treated like this any crop will be inferior both in yield and quality 

 to what it would be if properly treated. This sort of irrigation is 



.a waste of water, a waste of work, and a waste of money ; and to 

 make matters worse, if there should suddenly be a shortage of 

 water, there would be a great risk of losing the crop or getting a 

 poor one. But this is not peculiar to South Africa : beginners in 

 other countries frequently make the same mistake. They don't 

 think about the sub-surface soil ; they forget that the proper place 

 for most roots is deep in the ground and not in the surface layer ; 

 they perhaps do not know that roots will go to water, and if the 

 top surface is damp and the sub-soil dry, the roots will remain in 

 the surface layer ; they overlook the fact that evaporation and heat 

 will soon dry out all the moisture in the surface layer ; in short, 

 thev have done nothing to induce the roots to grow downwards 



.and to find their water supply in the lower layers of soil. In spite 



