CROPS UNDER GLASS 



55 



Question: Do I understand this sand is put on top or 

 mixed in? 



Mr. Zuck: We mix it all through. 



Mr. KiLBOURN: We have a medium light clay loam and 

 use large quantities of manure and bone meal. 



Mr. Yoder : The soil of this location is rather a sandy loam 

 and the soil where we had our previous experience was a 

 little heavier. So far we do not seem to be able to get quite 

 as heavy a lettuce on the light soil as we did on the heavier 

 soil. I do not know whether it is the soil entirely. Our 

 present experience seems to indicate that the heavier soil 

 gave us heavier lettuce. 



Mr. Wo?.k : Your soil where you are now is fairly light? 



Mr. Yoder: I would not call it very light, but rather a 

 sandy loam. We water with sub-irrigation. 



Mr. Work: Our conclusion with regard to lettuce from 

 what has been said would be that a soil that has somewhat of 

 the heavier elements in it would be better than the very light 

 soil ; and yet if the soil is very heavy to start with, we must 

 lighten it somewhat. Manure, I suppose we would agree, 

 would be the most valuable material for the purpose, but if it 

 is very heavy, applications of sand thoroughly worked in 

 would be very useful. 



Question : How much manure would it be safe to use, 

 fifty per cent? 



Mr. Zuck: That is a hard question to answer. The gen- 

 eral practice among all growers is to add a very heavy appli- 

 caticn in the summer, probably four or five inches. It maybe 

 fresh manure or partly rotted manure. Then the practice is 

 to add a partly rotted manure after each crop of lettuce is 

 cut, and also the practice among many growers is to mulch 

 cucumbers and tomatoes with fresh manure to conserve the 

 moisture and to supply plant food. Thus there are in all 

 several applications during the season. 



Mr. Work : In the course of the year the soil gets eight 

 inches? 



Mr. Zuck: Fully eight inches. 



Question : How many crops of lettuce can you grow on 

 the same soil? 



