CORRESPONDENCE

Dominion, Volume 33, Issue 176, 20 April 1940, Page 17

CORRESPONDENCE

Preserving Sacks For Hay-Stack Cover

A Taihape reader, “P.J.8.,” writes: “What proportion of bluestone is necessary to make a solution for preserving manure sacks for a haystack cover i Perhaps you may 'be aible to tell me of a better method. The cover has been on the stack some time, but I am anxious to treat it now before winter.” A first consideration is the condition of the bags to start with. Discussing the salvaging of the bags, an Australian expert writes: — ■ .. . “The present cost of bags to the farmer warrants the saving in good condition this season of as many as possible of the supenphosphate and other fertilizer bags after the manure has been distributed. But, if the bags are not washed the fertilizer left in the. walls and bottom will soon cause thc-m to deteriorate. One excellent way to wash the bags is to thread them on wires and then leave them in a creek, river, or dam for a few days. The fertilizer is thus dissolved out of the bags, and when taken out and dried they can be stored, away till required.” It is questionable whether it would pay to do anything in the way of treatment of manure 'bags that were not very clean when made into a cover. I have come across one or two cases of disappointments arising on. that score. Treatments commonly heard of are the use of used car oil (which has not been really satisfactory), of tar which has a fair record, and of bluestone, which is as good as any, so far as I have heard, and has the added advantage of easy and cheap application. It appears that there is no actual standard dressing. In one case salt is added to the bluestone as an improver. This is, however, viewed as more likely to destroy than improve the dressing’s value; salt is definitely disapproved. In several cases, a solution of 4oz. bluestone (copper sulphate) to two gallons of water is used. This represents a 1 to 80, or 1-J per cent, solution. A chemical authority, cliaming no actual experience and so speaking solely from principles, suggested that the strength of the solution should not greatly matter, but advised making the strength over 5 per cent. (That would be a limit of 11b. bluestone in two gallons water) In the light of all that has been gathered I suggest bluestone as a most suitable dressing in this case, the strength to be from 41b. to Jib. to two gallons ot water. Frankly, however, I do not put this forward as authoritative. Readers who have had practical experience could oblige by writing to me.