IMPORTANCE OF CLOVERS

Timaru Herald, Volume CXLV, Issue 21186, 5 November 1938, Page 15

IMPORTANCE OF CLOVERS

RESPONSE TO IRRIGATION HIGH PRODUCING PERMANENT PASTURE In the last issue of the New Zealand Journal of Agriculture, Mr W. C. Stafford, Instructor in Agriculture, Timaru, contributed the following interesting article on the importance of clovers in permanent pasture and the response of clovers to irrigation:— The clover content of to-day’s permanent pasture is the measure of its productivity. Every writer and speaker on pasture improvement and maintenance emphasises the importance of keeping up the clover content of the sward if high-producing permanent pasture is to result. The reason given for the importance of clover is its ability to supply nitrogen in a readily available form to the grasses of the | sWard. and nitrogen is the most important factor in the growth of all 1 grasses. Common Objective Throughout New Zealand we have I therefore one common objective—that j of introducing and maintaining in the j pasture sward clovers which are of such a type that they will produce 1 abundantly over the greatest period of , the growing season. It is evident from reading and hearing lectures that where the correct strains are sown this desirable result can be brought about in the North Island chiefly by the application of phosphates. There are other factors affecting the result, such as management, and in certain places other fertilisers and lime, but the general recommendation for the North Island is phosphates. It would further appear that the farmers themselves in the North Island have become fully aware of the importance of the clover content of the permanent pasture sward. This consciousness can only have resulted from the farmers I seeing for themselves what clovers ; mean to their pastures, and the consequent returns. Canterbury Pastures In the South Island, especially in the drier areas, such as Canterbury and Marlborough, from whence, incidentally, the greater portion of our clover seed comes, the importance of the * clover content of permanent pasture is not fully recognised by farmers. This ■ is undoubtedly due to the fact that under normal conditions in these areas clovers, because of their short growing season, are unable to exert their full beneficial influence in the sward. J. W. Calder, of Lincoln College, in a paper given at the Grassland Confernce in 1936, recognising the need for improved clover growth in Canterbury pastures, mentions the following pointy which should be carried out in endeavouring to encourage clover growth. (1) The sowing of improved strains i of certified white and Mont- ; I gomeryshire red clover. ’ I (2) Sowing at the correct season of , | the year to ensure successful es- , : tablishment. : i (3) Adequate liming and manuring.

(4) Correct grazing management for the benefit of the clovers.

He also mentions that the sowing of subterranean clover will ultimately have the result of improving Canterbury pastures. It has been proved that attention to these points has improved the clover content and, consequently, the pasture wherever they have been carried out in Canterbury. Standard Not Reached The fact remains, however, that even with these points being thoroughly exploited the standard of Canterbury, Otago, and Marlborough pastures has not reached that of the North Island. To find the reason for this one only has to ask any farmer ofi these areas, and the reply will be: “You can’t expect to get pasture here like the North Island. We don’t get the rain they get there.” If the above remark is right, and assuming that clovers are responsible for the health and strength of permanent pasture, the rainfall is then the chief limiting factor in clover growth on the light soils of the South Island. Two years’ results have proved this to be the case. Under proper irrigation, where the manurial requirements have been satisfied, clovers thrive with vigour equal to that of the North Island, and similar benefit to the associated grasses ensues. Attention to Clover Content In all cases proper irrigation of pasture has resulted in increased clover growth, and, further, old worn-out pastures which, prior to irrigation, were practically devoid of clover have become well filled with volunteer white

clover, thereby rejuvenating the sward. From observation it has become apparent that clovers are the first plants in the sward to benefit from irrigation. It is therefore essential that, where pastures are sown with the intention of irrigating, due attention should be given to the clover content of the mixture used, and the farmer should not depend on the fact that “my land is full of clover seed.” On the demonstration area at Mr W. R. Hammond’s farm on the Winchmore Irrigation Scheme in Ashburton the value of the good-type white clover is well brought out. Tire results obtained from sowing 3 lb. of certified white clover with 30 lb. certified perennial ryegrass, 2 lb. certified dogstail, and 3 lb. Montgomeryshire red clover show that under irrigation a good-type white clover is probably the best clover that can be used. With the adequate

moisture, liming, and manuring, this pasture has established quickly and is producing well. A examination of the sward shows that it is the certified white clover which is resposible for the bulk of the clover growth. The results for this 36acre field will be published in the Journal when sufficient material is available. It is sufficient at this stage to emphasise the fact that the difference between the irrigated and non-ir-rigated areas lies solely in the clover content of the sward. Guide for Irrigation ' Another important fact worthy of note is that, while the clovers respond so readily to moisture, they are also the first species to suffer when a excess of moisture is present. They can serve as a valuable guide to the irrigator, therefore, as to whether he is irrigating efficiently, as any effects of overirrigating will be immediately reflected in the clover growth. It is therefore essential that fields should be laid out in such a manner that they can be irrigated quickly without having water running over any one part longer than necessary. Provision must be made for any surplus water to be carried away and prevented from lodging on parts of the field. Under irrigation, the clovers become the indicators of the good or harm being done to a pasture.

Generally speaking, the results obtained on irrigated pastures over the last two seasons would indicate that irrigation will ultimately become as important a factor in South Island pastures as phosphate is now to those of the North Island.