Table 4 compares the percentage of fluorescent seedlings for Ariki, with short rotation and N.Z. The Tasmanian is undoubtedly the best of the introductions, but shows any advantage only at Lincoln, where it is superior to the N.Z. In Table 6 a comparison is made of chickens per square foot from a hard grazing trial at Kaikohe by Lambert, and from strong grazing and poor grazing trials at Lincoln by O'Connor for Ariki, short rotation and N.Z.
The author wishes to acknowledge the intense interest and encouragement of the late Dr P. Almost all trials in the farm-scale series involved a comparison between perennial ryegrass and Ariki ryegrass, while half of the trials involved a comparison between short rotation and Ariki. grains (see table 4). To date, the new hybrid has resisted damage in three trials by the Argentine fungus (Hyperodes bonariensis) when adjacent fields of short-rotation rye were stripped.
The only conclusion possible at this stage appears to be that palatability is a factor linked to growth stage or soil fertility and more management experience will be needed before assessing the relative palatability of ariki ryegrass and its parent types under different conditions can be made. assessed. A lamb fattening trial conducted at Wakanui (Ashburton) last spring resulted in a 1.1lb live weight gain (significant at the 5 per cent, level) over five weeks in favor of mobs grazing perennial ryegrass. Clear evidence of the superiority of ariki ryegrass over short-rotation ryegrass has been obtained in northern districts or where Argentine knotweed infestations occur.
Productivity
The most satisfactory evidence of livestock performance on Ariki ryegrass pastures has been obtained at the Ruakura Livestock Research Station. Twelve sets of identical twins were assigned to the experiment: one herd of 12 grazed 10 one-hectare plots of perennial rye, and their 12 co-twin pairs grazed the same plot of Ariki rye. The results during the first year are included in the appendices, but briefly there was an increase of 10 lb or 4 per cent of butterfat per cow and an increase of 11 lbs of butterfat per acre for the Ariki group, despite a reduction. in the lactation period compared to their husbands in perennial rye.
Grass production has been measured in this experiment (according to the electronic method developed by A. G. Campbell) and has shown a net gain of 8,900 lb. of dry matter per acre for perennial and 9,500 lb. dry matter for Ariki ryegrass, representing almost 7 percent difference in growth, which is roughly consistent with the livestock numbers. The season as a whole was notably free of metabolic disturbances in the Waikato, only one case of milk fever occurring (on the perennial block). No cases of milk fever or grass swings have occurred in either group during the just completed calving season (winter 1963).
Over three years, the new selection has been as hardy as perennial ryegrass and has shown faster recovery after drought or grazing.
Adaptability
Compatibility
Suitability for Livestock
Other Factors
ESTABLISHMENT TRIALS ON RYEGRASS AND CLOVER MIXTURES
Only a small amount of data obtained will necessarily be presented, and opinions are deliberately omitted. Half of the plots received urea at 2 cwt per acre at planting and an additional dressing of 2 cwt per acre was applied to these plots on July 15. Higher yields were obtained from short-rotation rye than from plots of the new hybrid.
The white clover yield was higher in the new hybrid plots than in the short-rotation ryegrass plots. The white clover yield was higher in the new hybrid plots than in the short-rotation ryegrass plots. The results presented above are very similar to those obtained from an experiment with the same layout carried out in the previous year.
In fact, because new hybrid seed is lower than short-rotation seed in the first six months from planting at comparable seeding rates and grazing heights, it establishes successfully. The most successful clover establishment is achieved when early competition is reduced by reducing the seeding rate of the grass component in the mixture. Dr Barclay had examined the characteristics of the new variety, Mr. Bascand had reported on field performance from trials across New Zealand and Dr Brougham had reported on establishment research.
It had resulted first in the breeding of short-rotation rye (from crosses between perennial and Italian rye), which was actually an improved Italian ryegrass, and now Ariki (from crosses between perennial and short-rotation rye), which was an improved perennial grass. After a dry summer, there was a much greater dominance of clover in the area in short-rotation dry grass than in Ariki. In the evidence that Mr. Bascand reported, total dry matter yields appeared to be the same; apparently Ariki's percentage was greater.
The total dry matter yield in the grassland sown with A r i k i was 5: percent above the perennial grassland and 8 percent above the short rotation ryegrass field. The ryegrass content of the Ariki meadow was 25 percent higher than that of the perennial and 35 percent higher than that of short-growing ryegrass.
A REVIEW OF ADVANCES IN TUSSOCK GRASSLAND
It was the use of the plane for poisoning the rabbit rather than for seeding and topdressing that made possible the truly dramatic changes in herd pastures. Without the "killing and debilitating" policy of the Rabbit Extermination Council, aided by the technique of aerial poisoning, advances in the stripping economy must have been inevitably slow and laborious. Warner (1956) made a study of the effect of rabbit destruction accelerated by the use of the new aerial vehicle.
Some idea of the effects on a national scale is provided by export data. He showed that “the present climate pattern can easily be related to the pattern of vegetation zones. Our knowledge of the biology of at least three shrubland grasslands was greatly enhanced by the publication of a series of 18 articles in the New Zealand Journal of Agricultural Research between 1958 and 1960.
An outstanding contribution to our knowledge of the soil microflora was made by Robinson (1962) as a result of his studies of a virgin grassland Craigieburn soil in the Castle Hill Basin, Canterbury. In the period under review, the Soil Conservation and River Management Board introduced the US system of soil capacity classification. It is widely applied by land conservators of the Land Conservation and River Control Council (since 1955 of the Department of Agriculture) and of catchment area authorities.
It also provides objective land evaluation tools in the land evaluation process. Range condition is the health or status of the range, and a range in the strongest or highest health condition is one that has. Now one wonders how much of the disappointment was due to the rabbit and the lack of fertility.
Connor's work on the development and growth of flowering stems of plants from the tussock grasslands (Connor 1963) is one. The great advance in mechanical aid, the use of the flying machine, has already been mentioned. Of particular value has been their study of tuft grassland soil sequences based on the genetic classification of the Soil Bureau.
1962b: A field experimental assessment of soil fertility in the highlands of the South Island, New Zealand.
A pot experiment showed that the level of available phosphate in these soils was well evaluated by the Truog test of the Depart-. Although the amount of phosphate applied to the Mod-P soils is of the same order as that on the High-P soils, the level of available phosphate did not build proportionally. The high application rate on the High-P soils kept the level of available phosphate well ahead of the losses in farm products and through phosphate fixation p r o c e s e s .
The objective of the trial was to compare the effectiveness of phosphate two and three years after application (residual effect) with the effectiveness of phosphate in the first year of application. The soil-pasture-phosphate relationship in fast-growing spring and early summer pastures differed greatly from those in slow-growing fall and winter pastures. The phosphorus content in the pasture was the highest in the spring, but fell to the lowest values overall.
Some of the differences between second and third year phosphate are not statistically significant, but there still remains an unexplained difference. Summary: In the period of rapid pasture growth (spring and summer) the response rate to phosphate was lower, the phosphorus content of the pasture was higher and the effectiveness of residual phosphate was greater than in the growing period slow grazing. . These differences between the two periods of the year indicate that soil and residual fertilizer phosphorus is more available to pasture in spring and early summer than in fall and winter.
However, the demand from the fast-growing spring pasture was 0.14 lb P/at/day (23 oz superphosphate/ac/day). In addition, these processes are influenced by the moisture content and temperature of the soil. The availability of soil and fertilizer phosphorus at any time of the year involves the integration of soil and plant factors.
Since there appears to be a very high residual effect in spring and summer, it is probably better to carry out all annual top dressing at once in early autumn to compensate for the lower soil phosphate availability in autumn and winter : the residual effect would meet the needs of the spring pasture. A transition to phosphate fertilization only in the autumn and to low doses on phosphate-rich soils should occur without affecting the potassium requirement of the soils.
