This paper is confined to a discussion on farming in two counties, Southland and Wallace. In this territory is comprised some 5,000 square miles of occupied land, which represents ‘7.8 per cent. of the Dominion total. In the Southland County there are 4,241 holdings averaging 476 acres, and in Wallace 1,514 averaging 793 acres. The combined figure of 5,755 holdings gives an indication of the number of farmers in the two counties.
Farmers throughout New Zealand agree that grass grubs, or the larvae of Odontria zealandica, are the most serious insect pests of pasture. Though damage is not conspicuous every year in established pasture, there is usually a certain amount of annual thinning out of valuable fodder plants and their replacement by weeds such as plantain, dandelion, mouseeared chickweed, and weed grasses such as sweet vernal and hair grass. It is difficult to estimate losses involved in this way except by close inspection of pastures or by a fall in farm returns. For example, one dairy farm in the Waikato produced over 80001b. less butterfat this :year than last, and yet it was only after a careful mspection that it was found that these pastures-though they looked uniform from a distance- had deteriorated by approximately one third. Though no definite sequence of grass grub damage can be predicted, it is common for an infestation to build up over a period ranging from 1 to 8 years, with damage becoming progressively worse from an original patchy effect till the pasture is more or less uniformly infested.
When I took over the ownership and management of my farm of 285 acres of terrace land 29 years ago, there were four 50 acre paddocks and two 47+ acre paddocks, six in all, a stable with a lean-to on it, plenty of open, unfenced ditches, and in a lot of cases gorse hedges used as subdividing fences. However, under the old system of farming then in vogue when grain growing was the chief source of revenue, these paddocks were not unduly large. It was then carrying 450 ewes and a five-horse team. It took 25 acres of turnips to winter the ewes. The lambing percentage was much lower than today, and very few lambs were drafted fat off their mothers, and had anyone then suggested that in 28 years’ time one would start lambing with 1275 ewes, that 1500 lambs would be tailed, and that 70 per cent. of these would go away off the mothers, such a statement would have appeared fantastic, yet that was the capacity of the farm in the 1948-49 season.
In the field numerous factors operate to influence the germination and establishment of clovers, and Mr Sears, in the final naper in this series, shows how complex the problem is. It is impossible by field observation alone to disentangle the effects of all these factors and to decide in any particular case just which of them have been of importance in giving the observed result. It is thus essential for a better understanding of the behaviour of clover seedlings that certain variables, for instance nutrient supply, should be held constant while studying the effect of controlled variation in another, for example light intensity, and this is only possible under controlled conditions in a laboratory. This does not mean that the results of such findings will be of direct and immediate application in pract.ice, but rather t,hat. without. a knowledge of the fundamental reactions of seedlings to such factors as light, temperature, and nutrient supply, pro,gress in the field will be hampered.
Soil is the product of five soil-forming factors: rock, climate, vegetation, topography, and time. When one considers the wide range of each of these five factors, it is easy to visualise the large number of possible combinations. This is particularly true of New Zealand, where there are wide ranges in climate, vegetation, and, in some areas, parent material.
The farming of any particular region must be approached from the aspect of climate. My placing of Southland as a climate would be midway between the climate of the greater part of the North Island of New Zealand and that of the lower half of Britain.
The papers that follow in this symposium will deal with various aspects of the behaviour of clover plants, but mainly with the reactions of seed and seedlings to environmental conditions. It is reasonable therefore at the outset to consider the nature of the clover seed and the ways in which the properties of the seed may vary.
This paper will chiefly concern itself with a discussion of what are generally referred to as the low tussock ,grasslands of the high country, called by Cockayne the montane tussock grasslands. I wish to make it clear that I am not concerning myself with those areas of tussoek which can be brought in under the plough and which are usually known as lowland low tussock grassland.
As much of the better country has been developed, it has become increasingly necessary to turn to the improvement of the poorer types.
Detailed studies of single species such as have been given by the previous speakers provide an essential background for a full appreciation of the various combinations applying in the field
Until 1938 the Grasslands Division carried out all its critical studies at Palmerston North. A substation was then established on the Crop Research area at Lincoln, in Canterbury. In 1945 the Gore substation was established. A most important reason for the establishment of sub-stations is to be able to continue studies in different climates and to investigate any problems specific to a particular region. Climate is a reflex of many interacting factors such as temperature, rainfall,. length of day, wind, etc.
To maintain a high rate of production from pastures one essential is an adequate supply of nitrogen, and this supply can be assured most economically by introducing strong-growing clovers into the sward. Sufficient clover plants can be readily established on arable. land by employing a suitable seed mixture when the pasture is renewed. On unploughable land, however, there are no opportunities for the complete renewal of pasture, and other methods of introducing clovers have to be found.
Timothy (Phleum pratense) as a pasture species is well known as a late-maturing grass which thrives in damp situa%ions but also grows quite well in a variety of soils. It is a highly palatable grass requiring a relatively fertile soil and apart from growing well in temperate climates shows to advantage also in the colder temperate zones. Timothy has been most extensively used in the United States of America, and is regarded as an important species in Canada and in northern Europe. In Sweden it is considered to be the most important of the hay grasses. In each of these countries it has been grown either alone, or with red clover, to provide hay crops, but in recent years the increasing interest in grazing pastures has suggested the necessity to locate and develop varieties or strains of timothy specially adapted for use in pasture mixtures.
At the time colonisation commenced in New Zealand, about one hundred years ago, there were two main and distinct types of ve,getation. First, there was the tall-growing association of forest trees, shrubs, and fern, which was confined in the main to the North Island and to the higher rainfall areas of the South Island. Second, there was the xerophytic grass-dominated association, which was present in the lower rainfall areas on the eastern side of the main divide of the South Island. This association was able to survive under the conditions of low rainfall, high summer temperatures, and low winter temperatures, and the constant desiccating winds. This grass association extended from high altitudes to sea level and was, in general, present in all areas where forest was unable to survive. A similar association was also present in the high altitudes of the central plateau of the North Island.
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