LIQUID MANURE Tonic for Poor Pastures

New Zealand Journal of Agriculture, Volume 69, Issue 2, 15 August 1944, Page 143

LIQUID MANURE Tonic for Poor Pastures

P.S. SYME,

i| ; By

Instructor in Agriculture. " ' ■ ■ Workworth .

Since attention was first drawn to the potential value of cowshed washings by Mr. A. G. Elliott in 1939, and the methods, as pioneered by Taranaki farmers, were later described in a series of articles by Mr. G. A. Blake in 1941, the use of liquid manure for topdressing has been gradually spreading to other dairying districts. The fact that increasing numbers of farmers are now turning to good account shed washings which formerly were either neglected or very wastefully used is ample evidence that the practice is being found well worth while. . 1

THAT animal manure is unrivalled . by any other fertiliser available is well demonstrated by the vigorous grass growth surrounding old cow droppings. It is also commonly noted that on many very poor swards the only ryegrass present may be found beside decomposed droppings, and this affords additional proof, if any were needed, of the unique value of farmyard manure in improving a poor pasture. It is noteworthy that while many farmers will go to considerable trouble to spread and utilise cow droppings in the field, they often make little effort to use what falls in the shed. Yet both are equally valuable. It is largely a question of economics. Analysis Not Everything Experimental evidence suggests that over the year the shed droppings available from a herd of 50 cows would be approximately equivalent to lOcwt. sulphate of ammonia, lOcwt. potash salts, 4cwt. superphosphate, and 4cwt. of lime, and would be worth about £lB. Considering that the acreage of land in New Zealand which is deficient in potash is relatively small, and that nitrogen can be supplied by the clovers free of cost, it must be conceded that these figures do not make an impressive showing on paper. However, the impartial observer will readily admit that, judged by practical test in the field, the response from an application of liquid manure can indeed be spectacular, and there is growing evidence that the figures of analysis may tell only a minor part of the story. Indeed, it has been claimed that the value of animal manure in promoting

mycorrhizal associations and its ability to provide the plant with essential substances somewhat comparable to the vitamins which plants supply to animals may far outweigh the fertilising value of the inorganic constituents as assessed by analysis. Profit Margin Small While shed droppings should be utilised wherever practicable, the margin for profit when installation and distributing costs are considered must obviously be small. Enthusiasm should not be allowed to override common sense, and the prudent farmer should first consider whether the use of liquid manure, is economically practicable on his farm, having regard to considerations such as the amount available, the topography of the farm, the cost, of installation, and the labour involved in distribution. Designing the Layout . If the scheme appears sound, consideration might then be given to deciding: the most convenient layout. If the shed is on high ground, it may be possible to use gravity and save on pumping apparatus, an important factor from the viewpoint of installation costs. Again, it may be convenient to wash the sweepings direct into the distributor and so save the cost of a collecting tank. Much has been said regarding the value of a collecting tank in permitting time for a “ripening” process, but, judging from the excellent results obtained by direct application, it is exceedingly doubtful whether the “ripening” is of any importance whatever. There can be no doubt,, however, that from the view of

convenience and the economical use of labour a large storage reservoir has much to recommend it. Although a very elaborate design involving heavy capital expenditure is likely to be unwarranted, it is generally agreed that any facilities tending to make the distribution less laborious or less irksome are worth careful consideration. In this connection emphasis is commonly laid on ample storage capacity and a speedy type of distributor,, motorised for preference. Farmer’s Experience While any farmer who is interested in the use of liquid manure can probably now obtain first-hand information in his own district, the experience of a Northland farmer. Mr. R. McKay. Taipuha, may still prove of general interest. Mr. McKay’s farm comprises an area of 300 acres, all flat or gently undulating. The land is for the most part poor gumland of very low natural fertility, and much of it has only recently been brought into grass. Although the farm now. carries some excellent pastures, portions of it have responded very slowly to artificial fertilisers and there has been a tendency to revert to browntop. Before making up his mind to install a liquid manure outfit Mr. McKay decided first to try out shed sweepings on a small scale, using a tank mounted on a sledge. A very short experience convinced him that though the results left nothing to be desired, the method left plenty of room for improvement. Accordingly, when he eventually decided to go the whole way, he determined that the distribution must not interfere with the work of the farm, and that it must be convenient and speedy. With this end in view he paid special attention to constructing a large-capacity tank which could be emptied at any convenient opportunity over a period of about 6 weeks in the flush of the season. Distribution, he considered, could best be performed by

a motorised outfit capable of quickly treating even the most distant fields. How well he has ' succeeded with the project may be judged by the following brief description:— Layout of Plant As will be seen from the x illustration the cowshed floor and yard, slope down towards the sump inlet. This inlet has been made of generous size, so that shed washings are easily swept in and carried off by gravity through a 6in. glazed underground pipeline. Provision is here made for diverting rainwater, or cleaning water which is too diluted to be worth carting. On its way to the collecting tank the pipeline runs through the calf bails, where it receives a useful contribution before passing to the collecting tank. As already mentioned the collecting tank is of large capacity. On the assumption that a ripening period might be of value the tank is divided into two sections, the over-all dimensions being 19ft. x ’l9ft. x 3Jft. and providing a holding capacity approaching 8000 gallons. The liquid from this tank flows by gravity into the distributor through a 6in. delivery pipe, so that no time is wasted in filling. The distributing tank holds 250 gallons and was constructed from an old steam boiler which was picked up at a nominal price. The plating is very strong and promises to be everlasting. As will be seen from the illustration, the boiler was cut down lengthways and part of the cut-away plating used to provide a deck covering. After trial it was found advisable to fit a special delivery cock which would open to the full bore of the pipe to prevent blocking. Cost Within Bounds Although the entire plant is highly efficient and was built to last, Mr. McKay performed the work himself and the costs have been carefully kept within bounds. The . actual out-of-pocket expenses were approximately as follows: —

£ s. d. £ s. d. Cost of holding tank: 3| tons cement .. .... .. 1710 12 Yards Shingle (on farm) ..300 2 Yards Sand .. .. .. 3 0 0 2 cwt. Reinforcing Iron 3 10 0 . 27 0 0 Distributor: Motor Truck .. say 20 0 0 Tank (converted) .. 12 10 0 Special full-bore Tap ..500 ■ i ' 37 10 0 Underground Pipeline: 150 ft. glazed 6in. pipe .. 15 0 0 , 15 0 0 Approximate total cost .. £79 10 0

Thanks to his insistence on speed and convenience, Mr. McKay is able to distribute about 5000 gallons of liquid manure in a single day. With a herd of about 80 cows the quantity of washings amounts to about 180 gal-

lons per day, so that the tank need be emptied only when convenient over a period of about six weeks. The rate of application depends to some extent on the type of pasture being treated, and it has yet to be determined what will be the optimum rate, and whether it is better to treat a large area lightly or a smaller area correspondingly more heavily. Used as a Tonic In the past two years Mr. McKay has made it a practice to conserve the liquid manure for those portions of the farm which are poorest and most likely to benefit. He has found that a

single application of about 2000 gallons per acre , can speedily bring about a marked improvement in the sward, and this he attributes partly to the manure and partly to the numerous clover seeds present in the washings. The way in which ryegrass and white clover have come in following treatment on areas which had given little response to artificial fertilisers has been quite astonishingly rapid, and it appears that the judicious application of liquid manure will eventually even up the quality of the pastures over the farm more quickly and. economically than any other means. With the relatively light applications used stock

have never at any time shown reluctance to graze treated pastures when once the herbage has been washed by a few showers. Results Uniformly Good Excellent results have been obtained at all periods of the year, but the benefits have been most marked in the winter period when normal growth is slowest. It is evident that the response obtained is no mere flash in the pan, and no written records are needed to indicate the fields treated. Indeed the improvement ' persists over a surprisingly long period and is still noticeable more than a year after the time of application. After two years’ experience with the use of liquid manure Mr. McKay is entirely satisfied with the results obtained. The benefits do not extend only to the pastures, however, for the problem of the disposal of the malodorous shed refuse is also satisfactorily solved. Making no extravagant claims on behalf of liquid manure as a fertiliser, Mr. McKay is content to let the pastures speak for themselves. They are more eloquent than he.