PASTURE GROWING PROBLEMS

Press, Volume LXIX, Issue 20937, 18 August 1933, Page 7

PASTURE GROWING PROBLEMS

— MANY PAPERS READ GRASSLAND ASSOCIATION CONFERENCE Papers on several aspects of grassland work, including details of the activities of overseas research organisations, of experimental problems as- i sociated with the investigation of the; subject, of fertilisation methods, and of pasture production under irrigation were read at the conference of the New Zealand Grassland Association, which concluded its session yesterday. Dr. E. Marsden, Director of the Department of Scientific and Industrial Research, presided over a large attendance of visitors from all jbarts of New Zealand. In a paper entitled "Grassland Work Overseas, Mr G. H. Hoiford, of Imperial Chemical Industries, Ltd., Cfcristchurch, surveyed the main features of the experiments being carried out in Great Britain, Europe, Canada, America. South Africa, and Australia, illustrating his address with lantern slides and a cinematograph film of aspects of the work in Australia. He described the work being done at the Aberystwyth Experimental Station in Wales, and at Jealott's Hill in England, and by the various departments of agriculture in New South Wales, Queensland, and Victoria. Mr Hoiford remarked that Australia was New Zealand's greatest competitor in grassland production, the life-blood of the Dominion. Australia was competing with New Zealand in the production of butter and lamb, and was getting good results from her 4,000,000 acres of sour grassland, compared with the Dominion's 16,000,000 acres. The Federal Government had allocated £250,000 for research and £IOO.OOO as a trust fund for the training of research workers. In Victoria a considerable proportion of the funds had been given by private persons and semi-private organisations. Grassland Experiments. "Obviously the most desirable type of grazing trial is One in which accurate measurements are obtained of the production in terms of marketable products, milk, meat, and wool," said Mr A. W. Hudson, crop experimentalist at the Plant Research Station at Palmerstcm North, in frits paper on "Th 6 Scope jpid Limitations of Some Types of Grassland Experiments." "Contrary to the opinions of those who claim that such trials aye easily conducted, I am definitely of the opinion, after somewhat limited experience, that this is not so. Variations in soil and stock introduce considerable errors, and the vagaries of weather conditions, resulting in fluctuations in production and recoveries of growth in relation to the time and severity of defoliation of the pasture, all contribute to making such trials by no means easy as a means of acquiring exact information and valid results." Mr Hudson discussed the advantages and disadvantages of "haying" trials in comparing different grassland treatments and the technique of the measurement of grassland - Ruction which had been develops during the last five years at the J-artip Experimental Farm. A Satisfactory Technique. "From the point of view of determining the yields from various fertiliser treatments, seed mixtures and strains of pasture plants at all seasons of the year, and under conditions comparable with those of rational grazing, I feel justified in saying that this technique is highly sat&faetcwy #©P ap-

plication to a lot of problems affecting our medium or better-class grasslands," said Mr Hudson. "It is not perfect, not do I think it is applicable to the solution of all our grassland problems, but for providing information on cartain matters it appeals to me as an accurate and comparatively cheap method." Mr Hudson dealt with the merits and demerits of observational trials and various experimental problems in their ratlion to technique. "In conclusion, I should like to refer to the not uncommon criticism that determination of yield in itself is not a satisfactory basis of measurement," he said. "This criticism, usually directed against fertiliser trials, generally arises out of the assertion that although a particular treatment may not increase the yield the improvement in 'quality' is sufficient to justify its use. My definition of a soil deficient in any constituent is one on which pasture- growth will be increased by its f application, providing uo other factor is limiting such effect. If the particular constituent is not a limiting factor I to production in the yield sense, I I know of no evidence which can justify its use on the score of 'quality* alone. Yield and improvement in quality may not be influenced in the same proportion when a deficiency is made up, but I am firmly of the opinion that, where a plant food is not so deficient as to limit plant production to an appreciable extent, any loss in quality from the ajiifnal production point of view is not a serious one. I consider, therefore, that increases in yield which do not take the quality factor into consideration err only on the side of being conservative in the estimate of their value, which is not a bad fault." Crested Dogstail. In his paper on "The Persistency of Crested Dogstail," Mr W. A. Jacques, of Massey Agricultural College, said that for a variety of reasons the seed had been neglected both by growers and selectionists. It come in for its strongest criticism at seeding time when the flower heads appeared, while in the remainder of the year any credit that ought to go to it was, owing to a resemblance of dogstail leaves to those of ryegrass, often given to ryegrass. It was safe to say that if these seed heads were not persistent there would be very little dogstail remaining in our pastures. It was to the exceptional power of re-establish-ment even under most adverse seedbed conditions and the power to produce viable seeds that enabled dogstail to persist in the pastures in the way it did. What was required, however, was a plant which would persist through its own vigour and one which would maintain that vigour for many years. This desire was legitimate if only to reduce the unproductiveness of this grass during the middle and late summer seasons. At present, where reseeding was general, the established plants weakened in January and either died during the dry- weather or recovered slowly in autumn with the advent of the rains. The casualties were replaced by seedlings which generally competed strongly for establishment on the available ground but seldom formed a close turf. There was thus a lag in production between the flowering season and the full establishment of the seedlings in late autumn, and this coincided with a critical season in. stock feeding. If this could be eliminated it would add considerably to the value of dogstail as a species suitable for serious inclusion in all seeds mixtures. Relative Values Tested. Mr Jacques described experiments which had been carried out to test the relative values of the dlflefent commercial lines of the sdlfecL in New Zealand in 1828 and 1830. The dogstail position in New Zealand at present was very unsatisfactory, *' ne said in conclusion. "All the New Zealand commercial seed has been tried, and of the two districts which supplied it, Southland-produced the|better article.

There are uo outstanding lines whiGh can be immediately used as a basis of improvement. This lack, of outstanding samples or regional, strains on which to concentrate makes mass selection impossible, and the slower patU by individual selection has to be tra"Dogstail is by nature short lived, but an early improvement in the matter of persistency is being sought by selecting the best plants from the survivors of the test plots, grouping tliem according to growth form, and increasing the amount of seed. It is considered that a more rational method, of seed production will be requlred itt order to maintain any improvement that is brought about." . Bush-Sickness In Stock. The results of investigations bushsickness Were described by Mr T. XMgg and Mr H. O. Askew, of the Cawthron Institute, in a paper on "Sojl ajid Sijaeral Supplements In of Bush-Sicjmess." The paper discu*ped a series of field trials held at Glei&iMMfc, Nelson, in the spring of 1931 a**d |SS2 to secure further information concerning the value of soil and Other iron compounds in overcoming the disease. "The most outstanding feature - these experiments is the great which has attended the use ofNelGOtt soil," said the paper. "It is reasonably to expect that many other New Zealand soils will prove equally valuable. Soils, therefore, may be just as iin* portant as the pastures growing thereon in supplying certain essential constituents required by stock. "The failure of Onekaka limonite in the Glenhope experiments suggests that the supply solely of suitable ironcontaining compounds is not sufficient for the prevention Of the ailment. NO suggestion at the present time can be offered concerning the value, of other —possibly minor—constituents in overcoming 'bush-siekness' at Glenhope but it must be emphasised that our knowledge of the exact role of eje« meats such as iron, copper, and ganese in the formation of haemoglobin is incomplete, and the presence of veiy small quantities of certain elements may have a profound effect on tp« proper functioning of the animal sy»* tem."