46 Journal of the Department of Agriculture. — July, 1922. 



Co-operative Ferlilizrr Exprrivieni at Zeenist. 



Plot 

 No. 



B^ertilizer Used. 



10 



11 

 12 

 13 



n 

 ir. 



IC, 



17 



Superpnosphate 



Kraal manure ... 

 (Control ... 

 Kraal manure ... 

 Superphosphate 

 Wood ash 

 Superphosphate 

 Kraal manure ... 

 Control... 

 Su{)erphosphate 

 Wood ash 

 Kraal manure ... 

 Wood ash 

 Kraal manure ... 

 Wood ash 

 Control ... 

 Wood ash 

 Sodium nitrate 

 Sulphate of potash 

 Su|)eri)hosphate 

 Sulphate of potash 

 Nitrate of soda... 

 Control ... 



Tlie i)otato, like the tobacco plant, prefers a soil rich, in potash. 

 Fortunately, this element is found in most soils in sufficient quanti- 

 ties to supply the needs of the crop, hut where a farmer has ashes 

 on his farm he can apply same with advantage to this crop. 



Tt is found that potatoes do well on acid soils, and for that reason 

 llie application of lime is not considered necessary, in fact, potato 

 <i;TOwers are of the opinion that lime is detrimental to the crop, in 

 Ihat it predisposes it to disease (scab). 



Rotation. 



It is essential that potatoes be grown in rotation with other 

 crops, otherwise diseases and insect pests peculiar to the croy> will 

 make the gfroAvino' of same almost impossible. 



The potato does well after a o-reen manuring- crop, as the latter 

 leaves the soil in a loose state — ideal for tuber pioduction. 



On drv-land 1he following four-year rotation mav prove use- 

 ful :— 



First year. — Maize. 



Second year. — Tefi', afterwards ])]oug-hed under. 

 Third year. — Beans fertilized. 



Fourth year. — Potatoes, heavily mnnured as recommended 

 above. 



(h- First year. — Maize. 



Second year. — Maize fertilized. 



Third year. — Cowpeas or kaffirbeans ploughed under. 



k'ourth vear, — Potatoes fertilized. 



