'-56 



]our)ial of Agriculture. Yicforia. [lo April, 1912. 



THE INFLUENCE OF SUPERPHOSPHATES ON THE 

 GERMINATION OF AVHEAT. 



By Alfred J. Eivart, D.Sc.. Ph.D., F.L.S., Governmeni} Botanist of 

 Victoria, and Professor of Botany and Plant PJiysiology, in the 

 Melbourne University. 



It has frequently been stated that when wheat lies in a dry soil for a 

 long time in contact with superphosphate of lime, its germination may be 

 very seriously affected. The fact was mentioned as long ago as 1905 in 

 the Journal of Agricidture of South Australia, page 135, and recent work 

 has confirmed this fact. It appears however that the injurious action only 

 becomes pronounced when there is a little free moisture to begin with and 

 the soil subse(]uentlv dries, and when this is so, any seeds which had 

 begun to germinate would die in any case if the soil remained dry for a 

 sufficient length of time. When the germination takes place fairly rapidly, 

 a stimulating rather than an injurious action appears to be exercised. In 

 order to avoid the possibility of the superphosphate injuriously affecting 

 the germination of the grain when it lay for a long time in contact with 

 the seed in a dry soil, a drill has been invented and placed upon the 

 market which plants the grain and superphosphate at different depth';. 

 Some plots planted iiT the ordinary way and with this drill were inspected 

 last vear, but it was not possible to make any definite conclusions from 

 them, except that the planting of the superphosphate beneath the wheat 

 did not seem to retard the growth in any way. Of course it should be 

 remembered that the special value of this mode of planting would only 

 become strongly apparent when the special condition mentioned prevailed, 

 namelv, a long period of delayed germination owing to the dryness of 

 the soil. 



In any case it seemed worth while to try whether mere contact with 

 dry superphosphate would affect the germination of wheat and also to 

 carry out small plot experiments with the grain and superphosphate planted 

 at exactly measured depths. This is necessary because the very best drill 

 varies a little in the depth at which the seed is planted, particularly where 

 the seed bed contains many stones or unljroken clods. 



The experiments were carried out by the Second Year Agricultural 

 Students (191 1) under supervision. In the first place experiments were 

 tried by storing dry wheat with an equal quantity of dry superphosphate 

 for three to six weeks, and noting the germination at the end of those 

 times. The following are the results : — 



Experiment. 



I. 



II. 



III. 



IV. 



Average 



Germination 

 coutrol 3 weeks. 



90% 

 96% 



91% 



' Germination 

 snperph. 3 weelvs. 



860^ 

 940c 

 91% 

 9,o. 



9 



' Germination 

 superph. 6 weeks. 



84% 

 92% 

 93% 

 80% 



87% 



Evidently when the grain and superphosphate are dry, little or no 

 injurious effect is exercised in a moderate length of time. In the follow- 

 ing plot experiments, in the plots " A,'' the grain and phosphate were 

 planted i inch deep. In " B " the grain was planted i inch and the phos- 



