SEAWEED AS A MANURE.

Dominion, Volume 5, Issue 1313, 16 December 1911, Page 8

SEAWEED AS A MANURE.

ITS USE IN GREAT .BRITAIN. AH round, the coasts of the British Isles and of other countries in Northern Europe seaweed has a high reputation as manure. There is 110 record, nor even any tradition, to show when it was first used or how its value was discovered, but it suonis to be essentially a Northern manure, and begin to bo mentioned os soon as descriptions were written of tho husbandry of the coast districts, says a Board of Agriculture leaflet, summarised in an English farming journal. In Scotland the right of gathering sca.wewl still sometimes forms part of the covenant with tho landlord, and has even been the subject of litigation. It appears to bo held in special favour on the southwest coast, where there is a good deal of light soil, and cartage presents no particular difficulties; indeed, it is perhaps the chicf manure used for early potatoes 011 the Ayrshire coast, being applied at the rate of 25 to 30 tons per acre in autumn, and then ploughed in. What is gathered in summer is put on top of the "middens" till wanted. Further up the west coast,, and also on some of the island's, seaweed is used by the crofters, but it does not appear to be held in so much favour on the east coast, excepting where it can very readily be obtained. Seaweed is still diligently collected in the west country; the amount available is very variable, and most comes into the bays facing south and south-west—the direction of the storms. In the market gardening regions of south Cornwall it is not, as a rule, used in tho fresh condition, but is mixed with sand as of old and allowed to rot. It is then applied along with guano and superphosphate, for early potatoes and cauliflowers.- Elsewhere it is put on to the root crops. On the north Devon coast ssawced is used for potatoes and roots:. so much is ■it esteemed as a spring dressing that a certain amount is sent by barges to points inland for the use of farmers too far from the sea for cartage to be profit.able._ In the Isle of Tlianct it is used in several ways. The fresh weed is spread •it the rate of 10 to 15 tons per acre ever lucern or sainfoin in the early autumn, and then raked off in. spring just before tho crop skirts. It is also put on the land at the rate of 10 to 15 tons per acre before ploughing, and is found to !>e very beneficial to such.market-garden crops as cabbage, celery, asparagus, etc., as well as the ordinary farm crops. Some is also thrown into the dnng mixen. It cannot, however, be said to bo a. very important manure at the present timo, and is connected only when other work can be left, tho reason probably being that cartage is heavy. A load weighs about a ton, and after requires two horses to get it from the shoro. . . , , The material gathered by the farmer is rather mixed, though one or. two species usually preponderate, especially if, "» sometimes happens, the seaweed is cut from the rocks. These British results of analysis may be summarised as follow:— Wet weed as gathered. Average. • Per Cent. Per Cent. w a tc r 70 to 60 75 Organic matter 13 f° 2 no Nitrogen .j® •Potash 0.8 to l.j 1.2 Phosphoric acid ... 0-12 to 0.17 0.09 A considerable amount of water is lost on drying in the. air, but if the weed has not been washed by'rain in the meantime, its content of nitrogen, potash, and phosphoris acid is increased, four, five, or even six-fold. .. , , It is difficult to form an estimate ot the money value of senwecd to the farmer. I'ho fertilising materials present in one ton of seaweed possessing tho average composition would cost Ss.. to 10s. if purchased from a dealer in the form of a merchantable manure in a finely divided state ready for putting on the land. This value is arrived at by allowing 12s. for each per cent, of nitrogen, 4s. for each per cent, of potash, and 3s. for each per cent, of phosphoric acid. No account is taken of the sodium, calcium, and magnesium salts, which on most soils, but especially light soils, would be distinctly beneficial; nor is any allowance mado for a possible stimulating effect,of the ir.dides present. It does not, however, follow that seaweed is worth Bs. to 10s. a ton on every farm near the sea coast. The question of availability of its constituents —i.e., of its decomposition under various conditions—would have to bo ascertained by careful trials before even a tentative estimate of its money value could bo made. In farm practico seaweed more or less takes tho place of dung, but there are several important differences. Seaweed contains no fibre, and, consequently, does not produce, .'ho black structureless material characteristic of the dung heap; in decomposing it-forms soluble substances which easily wash away. For the samo redson it decomposes moro completely than dung. It is even said to facilitate the decomposition of dung ou light soils and in dry districts, but there is no definite proof of this. A-ton of dung and seaweed would break down in the soil more quickly than a ton of dung alone, and would therefore have-less of a drying effect if put on late. The freedom of "seaweed from weed seeds and from spores of disease organisms is of considerable advantage on light soils where weeds are common. The high manurial value of seaweed has already been pointed out. On the basis of the current unit values, the fertilising materials in one ton of fresh seaweed would in a finish manure cost about 10s., and in one ton of dried seaweed about 40s' to , " '""thy of consideration whether it cannot be more widely utilised than it is at present.

THE POTATO MARKET. HEAVY SUPPLIES AND LOW PRICES. The locnl market is heavily supplied with potatoes just now, the new season's crop having been sent forward from all quarters, whilst old stocks are also coming in. The latter are practically unsaleable, only the very best meeting with any demand at all. New potatoes are in particularly heavy supply, choice sorts bringing Ss. to ss. Gd. per civt., and other sorts 4s. Gd. per cwt BUTTER FOR AMERICA. 7000 BOXES BY THE TAHITI. The steamer Tahiti, which sailed for San Francisco via the Islands yesterday, is carrying 7000 boxes of butter from New Zealand for tho American market. The shipment is made up of supplies from Onehunga, New Plymouth, and Wellington.