Farm Practice and Management

New Zealand Journal of Agriculture, Volume 66, Issue 1, 15 January 1943, Page 39

Farm Practice and Management

Tarweed In Pastures

A PROFUSION of any weed in cultivated land or in old pasture usually calls for little comment. Its presence can readily be explained as due to bad management or to some special condition of soil or climate, and far from being mysterious,. its appearance under existing conditions is only to be expected. When a weed, whose presence was not even suspected, however, suddenly appears in virgin land ploughed out of native teatree and sown in grass, one is to be pardoned from expressing surprise, and, where the weed is in such profusion as to almost smother the pasture, there is even cause for

alarm. Such is a very common experience with tarweed in many districts. Its sudden origin, like its equally sudden disappearance is something of a mystery. Various explanations have been given to account for this phenomenon. It is sometimes suggested that the tarweed was present as an impurity in the seed. This, however, appears extremely unlikely, as the plants are far

too numerous and commonly appear even where the best quality machinedressed seed was used. The more plausible explanation, and the one given by old settlers, is that the country was at one time sown in grass with the tarweed as an impurity. As the land reverted back to teatree, the tarweed was suppressed along with the grass. The seeds, however, remained in the ground dormant and owing to their inherent longevity were still suf-

Frost Warnings

IN the interests of national security the broadcasting of weather reports was, in 1940, suspended for the duration of the war. However, for the benefit of farmers, market gardeners, fruitgrowers, and other members of the public apprehensive of danger to crops by frost visitations, facilities have been made available whereby frost warnings can be obtained by enquiry from the telephone exchange at more than 100 post offices throughout the Dominion. If the district forecast gives any indication of frosts which may damage the crops, then the necessary precautions can be taken. While these forecasts are published in the majority of evening newspapers, it. is considered that the addition of this telephone advice service will be appreciated in many districts. Information regarding the particular post offices operating this service can be obtained from any postmaster.

ficiently viable to produce a vigorous germination when the land was broken up and conditions again became suitable. If this explanation is correct, it is evident that such seeds can live in the ground for very long periods indeed. The disappearance of tarweed from a pasture is more easily explained. This plant likes loose soil conditions and cannot compete with a vigorous growth of grasses and clovers, particularly where consolidation is promoted by heavy stocking. Although at first sight the prolific smother of tarweed in a young pasture may be very alarming, under good management little trouble is likely to be experienced after the first year. —P. S. SYME, Instructor in Agriculture, Warkworth.

Consolidation Versus Aeration

THERE is one aspect of cultivation which is given much prominence in nearly all articles on cultivation written nowadays, and which could easily be misapplied, viz., consolidation. There are parts of New Zealand, and also certain periods of the year when consolidation should be stressed, but the young and inexperienced farmer is apt to gain an altogether wrong impression of this aspect of cultivation, especially in Otago and Southland. If the soil is thoroughly cultivated, then under normal conditions consolidation .will invariably take place in spite of all efforts to prevent it. The point is how to arrive at a thorough state of cultivation. It is doubtful if too much reliance is not being placed

on the disc harrows as a means of obtaining a fine seed bed. It is quite true that the disc harrows are useful in the early stages of preparing the seed bed, but once a fair tilth has been obtained a better seed bed would almost certainly result by using a cultivator. Modern Methods Our modern methods of cultivation, using the tractor and disc harrows, are tending to drift from one of the main principles of cultivation, which is aeration of the soil. Prior to the advent of the tractor one of the most difficult problems of cultivation’was to eliminate air pockets formed by ploughing, and it became common to emphasise the necessity for consolidation when what should have been emphasised

was the necessity for thorough cultivation. ■ ■ In the early days when shallow ploughing gave good results there was no difficulty in this respect, but once the top soil had become exhausted, farmers found it necessary to plough deeper, not only to bring up fresh soil, but also to break the pan formed by continued shallow ploughing. This deep ploughing brought in its train the problem of the necessity of eliminating the air pockets, and often this was attempted by consolidation instead of by more, and deeper cultivation. It should be remembered that if deep ploughing is practised then deep cultivation must follow if maximum results. are to be obtained. The advent of the tractor seemed to present a solution of the problem of

eliminating these air pockets. Here was unlimited, or almost unlimited power, and consolidation could be gained by using bigger and heavier implements, and by giving the land an extra discing. All this could be accomplished in much less time than by horses. Ploughing could be done later, and when cultivation was commenced it was finished in a very short time; in fact in such a short time that one could almost say it was done in one operation. But did not this speed eliminate the very important factor of aeration Thorough Cultivation A new phraseology was adopted. It became the practice to speak of working a paddock down instead of working it up. Even the plough was used to bring about consolidation. Recently a splendid paddock of rolling country was seen being ploughed by a swamp plough. The reason given was that it was hoped the deep flat ploughing would bury the yarr seed which was very bad in this paddock. Little if any aeration can possibly take place in this paddock unless a cultivator is used, and the cultivation is spread over a period. In all probability it will be double disced a couple of times in the space of a day or two, and then turnips will likely be sown the next day. It is not intended to infer that consolidation is not necessary, but the point to be emphasised is that consolidation will take place of its own accord if the cultivation is thorough. Does the question of aeration not open up a big field of inquiry? In the past the control of plant disease such as club-root and dry rot was attempted by treating the seed, and by the use of chemical fertilisers, much in the same manner as our bodily ailments are treated with patent medicines. Just as it would be wiser to return to a better way of living, so in regard to plant diseases it would be advantageous to return to better cultivation, and aeration of soil. Take care of the cultivation and consolidation will take care of itself. —H. K. EDIE, Assistant Fields Instructor, Gore.

Internal Parasites

The annual mortality amongst hoggets from internal parasites is increasing from year to year, and on some properties is assuming enormous proportions. Similarly, losses amongst calves are proportionately high. Important information on this problem is available in the Department’s bulletin, “Internal Parasites of Sheep and Calves, and Their Treatment.”