294 



JgricuHural Gazette of N.S.TV, [Jpril 2, ]>»()«, 



contaiiiiiiif an inch jiiiucf Iwile, are also useful. Care must lie taken nut to- 

 rush too l)ig a stream down the furi'ows at first, or the soil may " slicken," 

 or become puddled, ami |>i(veiit percolation. In waterin<( maize oi' sor<ihum, 

 water is best applierl duw n everv altei'nate furrow to germinate tlie see(|, and 

 tlii'n down e\<TV row wlien tlir ])lants are growl nic well. 



Frequent surface cultivation is a most es.sential operation after furrow 

 irrigation. The settler who, when asked why he did Tiot use inoi-e hors(»-hoe- 

 and less water, i-e])lie(|. " 1 can sit down to irrigate, hut have to walk to 

 cultivate," explained a too commfm cause of failui'e amongst irrigators. 



AV'hen the soil connnences to ci-ack after irrigation, it is time to cultivate, 

 not irrigate. < )n clav soils the surface may he cracked and yet ilie suhsoil 

 may be saturated. For fruit-trees, wait until the soil is almost too dry to 

 "ball " when squeezed in your hand before watering again. Surface cultiva-^ 

 tion destroys the crust, lills up cracks, and by pi-eveming undue evaporation 



Furrow Irrigation on Clay Soil. 



ensures the necessary even degn>e of moisture. A good rule in irrigating is- 

 never to run watei' more than once over the same surface. (live a good 

 soaking, and when dry enough for horse-work, st ir the soil weekly. With 

 this treatment a 4-inch watering will last two months, whilst widiout 

 cultivation it \\ ill orilv last a few weeks. 



Tn all cases where the subsoil is not porous, underground drHinage is 

 absolutely necessary whei-t' irrigation is practised. A heavy fall of rain 

 falling after an irrigation may, in the absence of drainage, do considerable 

 harm, as the soil becomes waterlogged and aii- tight. With cmps of oats or 

 rape the leaves tui-n red and gi-owth is stunted, but with lucerne or fruit- 

 trees more disastrous effects follow. The roots decav, encouraging the attack 

 of " white rot," or " mal-di-goma." i>r the jilants mav be di'own«Ml for want of 

 air. Underground drain.s, which may be filled with stones, tea-tree, 

 logs, or any available material, take up le.ss room than surface drains, and, if 



