The objective of land settlement operations of the Lands and Survey Department is to promote the settlement of unoccupied Crown lands. In carrying out this-objective it is our job to grass, fence, drain, water, erect’ buildings, stock, and finally sub-divide and settle areas into economic farming units. S u c h improveme.nts are expected to be sufficient only to allow the units to “tick.”
1. As a result of the use of strains of perennial ryegrass and white clover and varying applications of artificial fertilisers, pastures differing widely in total annual and seasonal production have been established. 2. No differences in the thrift and productivity of ewes and lambs grazed continuously and. fed to appetite on the different pastures could be observed under a management system aimed at keeping the sward between about 1 and 4 inches in height at all times. 3. In particular, pastures containing white clover of high prussic-acid glucoside content showed no ill effects on thrift or production in ewes confined to these pastures for four years. 4. The more productive the pasture, the more pronounced were the seasonal variations in production and the greater were the problems of efficient pasture control. 5. It is postulated that criticism of these pastures on the grounds that they promote ill-thrift in stock has its genesis in a general inability to effect adequate control at all times.
From quite early days in the colonization of New Zealand farmers began to search for satisfactory methods of grassing and farming the great areas of light volcanic soils in the central region of the North Island. Even the earliest land-improvers seemed to think that these pumice soils were suitable for pastoral purposes, but for many decades their hopes, engendered by the excellent red clover growth in the initial pasture sowings, fell as the pasture swards ran out and sheep and cattle pined from bush-sickness. This initial excellence of red clover was certainly a factor which kept people perpetually interested in the land, for although the land is easily cultivated, the virgin pumice soils appear infertile and unattractive. This. aspect was commented on as early as 1839 by J. C. Bidwell, who, in recording his travels from Tauranga to Taupo, remarked “ . . . the land is not bad . . . I have seen clover and grass growing in the garden of a Mission or I might perhaps have thought the land was worse than it is . . .” It was the intuition that really intensive farming was ultimately possible on these pumice lands that kept invigorated the faith of such men as Aston, Clifton, Carr Rollett, and Earle Vaile in their work of seeking methods which would overcome the problem of pumice land farming.
Of the 5 1/4 million acres of total occupied land in the Wellington district nearly 4 million acres are in sown pasture, the remainder being bush, natural tussock grassland, scrub and secondary growth. Of this sown area a large proportion comprises hill-country farms running sheep and beef cattle and carrying an average of 1 to 2 sheep per acre. From the sheepfarming point of view the Wellington district is of major national importance, contributing nearly 22 per cent. of the total sheep population and almost 19 per cent. of the total beef cattle. The region as a whole carries the heaviest concentration of stock of all New Zealand.
Grassland farming is the basis of our primary production and insetit pests constitute one of the factors which limit or decrease that production. A survey of the relative importance of different pest species and of the means available for their control should serve a useful purpose. Such a stocktaking will help in comparing the pasture pest situation in New Zealand with that in other countries, and in indicating some of the overseas pests whose accidental establishment in New Zealand could be potentially very serious.
Grassland farming is the basis of our primary production and insetit pests constitute one of the factors which limit or decrease that production. A survey of the relative importance of different pest species and of the means available for their control should serve a useful purpose. Such a stocktaking will help in comparing the pasture pest situation in New Zealand with that in other countries, and in indicating some of the overseas pests whose accidental establishment in New Zealand could be potentially very serious.
This research station has undertaken a study of the water requirements of pasture in connection with its investigation of the system of overhead irrigation. No work had previously been published in New Zealand regarding the loss of water and soil nutrients in drainage water.
In this paper it is not the hill-country on which cultivating implements can be used that we are concerned with; it is all that steeper country which has been regarded variously as “marginal” or “deteriorated land,” and which also is the really difficult country to manage and keep in a productive state.
The process of natural regeneration of pastures is one on which during the past 20 years there has been a deal of discussion and experimentation, but on which there has, in this country, been little enough action on a practical scale.
The need for clover in pastures is becoming increasingly well recognised and has been adequately dealt with, particularly regarding hill country pastures in the two papers already presented this morning.
Of the grasses used in sowing down pastures in New Zealand, those of the genus Lolium (the ryegrasses) are the most widely used, as one or other of them forms the basis of practically all seed mixtures. The characteristics of the ryegrass species and strains available to the farmer to-day are, in some respects, very different from those of strains available twenty years ago. So that a comparison between those and the present pedigree strains may be made, I shall deal briefly with the changes that have taken place over this period.
Perhaps the feeding value and the soil protection value of herbage plants has been appreciated more extensively in recent years, and it may have been realised, also, that the plants which have successfully resisted soil erosion and provided useful fodder, hay, or seed are those which have become completely adapted to the soil, and to the climate, of the region in which they have been grown. With all useful plants important ecological factors have been the habit of growth, resistance to extremes of temperature, the period of the year in which most growth has been made, resistance to plant diseases, relative palatability, and a prime consideration alwavs has been how much forage any particular plant will yield. For soil conservation work the type of root, whether deep rooting or surface rooting, and whether fibrous or rhizomatous, always is of special importance.
In the short space of five minutes it is difficult to review the place of short-rotation ryegrass under. the varied conditions of soils, climates, and types of farming which are to be- .found in the area to be covered, namely the land districts of Poverty Bay, Hawke’s Bay, Wellington, .and Taranaki. The opinions of the Instructors in Agriculture throughout the area as to t.he position in their districts was sought and this review is based on these opinions. It is interesting to note that while experience with short-rotation ryegrass in one or two districts extends back to 1942 in the majority, seed of this species has been sown only in the past two or three years, while in some localities as yet there has been no real experience with it. First of all let us have a look at the position of short-rotation ryegrass as it affects the farmer. This can best be done under two headings-seed production and in grazing pastures.
The paper presented by Mr C. E. Iversen has covered the field of experience with short-rotation ryegrass in Canterbury and I would like to compliment him on his paper.
The data presented cover results from shortrotation ryegrass established over a very wide range of climate, soil, and farming conditions, Reports are based on sowings commenced in 1943 under annual rainfalls from 15 inches ,in Central Otago to 40 inches in Southland, and on soil types varying from light gravels of relatively low fertility, to highly productive deep alluvial deposits.
Short-rotation ryegrass has been fairly closely observed since its introduction to the Auckland Province about seven years ago in farmers’ fields and ,in trials. To define its place on .farms in this province it must be compared with Italian ryegrass and perennia! ryegrass. These two plants have played and important part in the agricultural development of the province and high production has been obtained on those farms only where ryegrass is the dominant species in the pastures.
Over the whole of the Central North Island there is a mantle of volcanic ash deposited as a series of showers, each one generally only a few feet thick. Except on the steepest slopes the underlying rock is completely buried, and it is on the ash showers that the soils are formed.
In 1943 a new ryegrass appeared on the New Zealand market, known first as Hl, but later as short rotation ryegrass. This new grass was a hybrid produced by the Grasslands Division, Department of Scientific and Industrial Research, and combined some of the more valuable features of its parents Italian and perennial ryegrass. Since that time the grass has been tried over a wide range of soils and clima.te with varying management and utilisation, so that the picture of its sphere of usefulness is now fairly clear. The characteristics of the grass as first produced are as follows
The all-year-round feeding of stock on pasture without ,the aid of supplementary feed is an end greatly desired by New Zealand grass farmers. In some of the milder areas of the north this end is often achieved, but throughout the Dominion various factors operate against twelve months grazing. These factors are climatic, geographic, and edaphic.
The popular belief among many is that clovers will not grow in acid soils, and for this reason large quantities of lime are often used to make soil less acid in an attempt to increase clover growth. At the Grasslands Division of the Department of Scientific and Industrial, Research at Palmerston North there have been a number of .experiments over the past few years which serve to raise doubts about the truth of some statements normally accepted as axiomatic as far as clover growth and soil acidity are concerned. Our experiments have been conducted in a number of ways, and some of these will be dealt with in detail.
I cannot claim any originality in the title of this paper, since during the past hundred years dozens of papers have been written under the identical heading and hundreds -have been written on the same topic. In the hour that is allotted to me I propose to discuss, not the mineral status of pastures grown under all the environmental conditions possible in New Zealand, but one or two small trials which have been under “;~-v; in Palmerston North during the past 3 years. reason for this intense specialisation will, I hope, become clear as the lecture proceeds, but briefly we are concerned with principles which will be applicable regardless of the environmental conditions rather than with applications which relate only to one particular climate or one particular soil.
The essential study in this paper is the examination of seasonal and yearly changes in the growth rate of pastures and pasture species in different districts, on different soils, and over a number of ‘years. It is impossible to deal with all aspects of the subject adequately in the time available, and I have therefore not considered in detail how or why these growth rate changes occur, -but have confined: discussion to an analysis of the differences in pasture growth rate that exist in varioiib parts of New Zealand. Again, because the measurement trials of the”,Department of Agriculture’ have so far been restricted td the Iiat and easily rolling country, comparisons are available only between better-than-average pastures under better-than-average management in the more productive districts of New Zealand. With the possible exception of some of the trials in Canterbury, all the pastures concerned are or could have been made dominantly ryegrass and white clover.
The title of this paper is “The Respective Claims of Forestry and Agriculture for Ploughable Scrub Lands.” This title was not chosen by myself, and I find immediately that it presents certain difficulties.
NZ Grassland Association Inc.
11 Montrose Street, Mosgiel, Dunedin 9024 New Zealand | P: +64 3 477 0712 | F: +64 3 473 6495 | E: nzgrassland@gmail.com
© Copyright NZ Grassland Association Inc. 2011. All rights reserved
Refund Policy | Disclaimer | Privacy Policy | Terms & Conditions