|dc.description.abstract||By far the greatest proportion of the 1,150,000 acres of light land in
Canterbury is found on the Canterbury Plain. This plain, originally covered
by "low tussock" and of easy contour, was enticing to the early pioneers and
became one of the earliest areas in New Zealand to be settled and farmed.
Over the years it has developed into one of the most intensively farmed and
productive areas of New Zealand.
The dominant characteristic of the light land of Canterbury is undoubtedly
the climate. The rainfall is reasonably evenly distributed over the year, but
because of the low humidity, high temperatures and warm winds experienced over
the summer in association with a free draining soil, the effectiveness of the
rainfall over this period is drastically reduced. Consequently active plant
growth is severely restricted for several months over the summer, and occasionally
extends into the spring and/or autumn periods. The uncertainty as to the length
and severity of this restricted growth period and the associated problem of
equating the variable feed supply to the stock requirements, both within and
between years, is the basic problem confronting the light land farmer.
In spite of the environmental difficulties the productivity of the light
land has increased several fold since early settlement. The original holdings
on the Canterbury Plain were large with their boundaries on the rivers so as
to provide access to water. Fine wool sheep were extensively grazed. However
the introduction of refrigerated shipping and the extension of the water race
system in the 1880's brought about a reduction in the size of holdings and a
change in the pattern of farming. Dual purpose sheep were run and by the 1930's in response to favourable crop prices the system of diversified farming
was firmly established. Unfortunately this system placed excessive emphasis on
cash cropping, particularly on the light soils. Soil fertility was drained,
structure severely damaged and subsequent pasture establishment and survival
poor. In the late 1940s and early 1950s, with declining crop yields and with
more favourable prices being obtained for fat lambs and particularly wool, the
emphasis shifted from cropping to livestock farming. The carrying capacity
however, was restricted by the reduced soil fertility and poor quality pastures
and an environment in which climatic uncertainty tended to inhibit the rapid
expansion of stock numbers.
The results of research work carried out at the various institutions in
Canterbury over the years have undoubtedly promoted a greater understanding and
appreciation of the problems confronting the farmer and the limitations of the
particular environment in which he must operate. For example, pasture species
more suited to the low fertility conditions and climate were introduced with
spectacular results. The most significant of these was subterranean clover
(introduced in the 1930s), noted for its ability to withstand the summer droughts,
to regenerate in the autumn, and to provide an increased bulk of feed in the
spring. Research work had shown that both lime and phosphate were necessary on
the light land soils, if high pasture production and persistency was to be expected.
Soil fertility increased subsequent to a reduction in the emphasis on cropping and
with the higher levels of fertiliser application. High fertility pasture species
(e.g. white clover and lucerne), were introduced and not only gave higher and
more reliable total production but exhibited improved seasonal spread of
production. Investigations into pasture diseases and stock health provided
answers to specific problems. Research into flock management generally and in
comparisons between the productivity of various sheep breeds indicated the most
suitable type of flock and breed for the light land farmer. From this and other research work (in conjunction with the observations of
leading farmers in the area), an efficient system of light land farming has
gradually evolved in which many of the basic problems have been overcome and
which has resulted in a raising of the carrying capacity of the light land from
¾ stock unit per acre in the 1930's to 3½-4 stock units per acre at present.
A central feature of this system (particularly at high stocking rates), is the
high degree of flexibility incorporated in both the stock policies and feed
supplies. Where the objective function is to maximise productivity over a
period of years, it is essential to utilise the available spring feed efficiently
while maintaining the ability to destock when confronted with feed shortages in
the spring and early summer. Because of the fluctuating feed supply, which is
characteristic of light land, the need to maintain feed reserves and to incorporate
a high degree of flexibility in the stock policy is evident if the feed supply
and demand are to be equated.
In summary, the increased productivity can be attributed to two factors:
(1) The ability to grow a greatly increased quantity of herbage
per acre with an improved seasonal pattern of production.
(2) A more efficient utilisation of the herbage produced.
Unlike his counterpart in more reliable farming districts, the light land
farmer operates in an environment of uncertainty. Yield uncertainty, particularly
at high stocking rates, is the major problem to be overcome and this dictates
very largely the system of farming adopted. Price uncertainty is also a significant
aspect of light land farming because of the reliance on a limited range of products
and the inability to diversify.
In an analysis of physical and financial data collected from a sample of light land farms in Canterbury (1) there was no evidence to suggest that any one
particular pattern of output was superior to all others. This result was
surprising, but may reflect the uncertainty inherent in the environment.
(1) For a full discussion on this, see Section 3.3.2(a). Alternatively it may infer that the actual patterns of production are less
important than the managerial skill with which they are implemented.
These results pointed to the need to explore more fully the following
facets of light land management:
(1) Given a developed farm, is there any one optimal pattern
of production which (a) generates increased profit under
average seasonal and price conditions, and (b) is subject
to only small variations in profit under changing seasonal
and price conditions?
(2) Given the potential for the development and expansion of light
land farming, how profitable is this from the individual
If, in an evaluation of the first problem, high levels of productivity
are shown to be profitable on existing well developed farms, then a reallocation
of resources to obtain the desired combination should be recommended. An optimum
combination of enterprises shown by such an analysis might well serve as the goal
where an undeveloped potential still exists on a farm and where a reallocation
and intensification in the use of resources is necessary if productivity is to
In this study of light land farming two case farms have been used and
although the results refer specifically to these particular farms, some
conclusions of a general nature are possible.
In Chapter II the physical characteristics of the area are described.
In Chapter III a review of the research into specific problems relating to
the management of light land is presented. This is followed in Chapter IV
by an explanation of the technical principles of light land farming which
have evolved. Chapter V is devoted to the comparison of some of the production
possibilities open to the light land farmer using linear programming. An analysis of light land development 1s presented in Chapter VI, while Chapter VII
presents the conclusions and summary of the study.||en