470 JOURJNAL OF THE DEPARTMENT OF AGRICULTURE. NoV., 1922. 



Agricultural Lime and Slaked Lime. 



^iiiionstuwn. — For au onion crop grown on a light sandy soil, is 

 slaked lime preferable to agricultural lime? 



KJnoihjirg ScJiool of Agriculture replies: In our experience of 

 light sandy soils, agricultural lime, i.e. finely ground limestone, 

 gives the best results, and is less jjowerful in its action on the organic 

 matter in such a soil. We have not tried the two forms of lime you 

 mention on onions, but see no reason why this crop slioubl ))•' different 

 from others. 



Continuous Maize Crowing with FertNizers. 



Jh't/ilehem. — Is it advisable to grow maize continuously and 

 rely for the maintenance of yield upon the use of fertilizer, or is there 

 any better system ? 



Glen School of Agricultinc replies : This question is bound up to 

 some extent with the amount and distribution of the rainfall. Where 

 the i"ainfall is abundant the yield of maize can usually be maintained 

 by the judicious application of fertilizer. Where water, however, is 

 the limiting factor in crop production, dependence for the mainten- 

 ance of yield should be placed more on the system of farming than 

 on the use of fertilizer. Yields of four, five, and six bags per acre 

 according to district can more economically be maintained by growing 

 a variety of crops, by the feeding-off of crops on the land, by winter 

 ploughing, by fallowing, by having one legume in the rotation, than 

 by growing maize continuously with the use of fertilizer. The return 

 from fertilizer is so largely dependent upon the season that the 

 farmer is liable to misinterpret its results. In 1920 a farmer gave an 

 application of thirty bags to sixty acres of maize, and obtained a 

 yield of 300 bags of grain, equivalent to ten bags of grain for every 

 bag of fertilizer. In 1921, counting on this ten to one ratio, he 

 applied thirty-seven bags to the same sixty acres, and calculated to 

 get 370 bags, whereas he actually reaped only 200 bags. 



Fertilising is a good practice, but it must be done judiciously: 

 otherwise money can easily be sunk in it with little hope of recovery. 



Ticks on Horses. 



Fauresiiiltli . — I am sending you specimens of ticks taken oflt one 

 of my horses whi(di run on the veld. Kindly identify. 



The Glen School of Agriculture replies : The specimens belong 

 to a species known as Lounsbury's or the Argentine tick {Margaropvs 

 withewi, Karsch). It is a vSouth American tick, which was probably 

 introduced during the Boer war. It is common in many parts of the 

 Oiange Free State, and is found principally on horses. The tick is 

 not known to be able to transmit any disease. (Read : '' Ticks Found 

 on Man, etc.," Agricultural Journal, July, 1920; and "Diseases, 

 Ticks and Their Eradication," Agricultural Jovrnal, February, 1921. 



