FARMING IN NEW ZEALAND

New Zealand Journal of Agriculture, Volume 79, Issue 5, 15 November 1949, Page 421

FARMING IN NEW ZEALAND

HpHE pastoral industries of New Zealand have been asked to accept' the task of endeavouring to produce an extra 50,000 tons of meat and 30,000 tons of butterfat within 7 years. This can be achieved only if most existing farms are made more productive through land improvement and more efficient livestock management. This article by P. W. Smallfield, Director of the Extension Division, Department of Agriculture, Wellington, is the first of four dealing, with proved land-improvement practices, some of which, if more widely adopted, will help to fulfil the immediate task of increasing food production, while others are concerned more with the long-term improvement of farming. These articles will deal with land classification and the general fertility-building and conservation methods appropriate to each class and with some of the more important variations imposed by certain soil types within each major land class.

KJEW ZEALAND’S first duty should ’ be the preservation and improvement of the fertility of the land. Apart from labour, the land is the country’s only real asset and must be the basis of its future well-being and wealth. The land of New Zealand has been farmed for just over 100 years, during which time fertility has been improved over little more than a tenth of the land and not a great deal has been done to mitigate fertility depletion on the remainder. Early farm practices conformed to. the demands of nineteenth-century industrialism for cheap food and raw materials demands which despoiled large areas of the virgin lands of the New World and caused the growth in the Old World of vast congregations of people unable to provide their own sustenance. In common with those in other new countries New Zealand settlers burnt and over-grazed natural pastures, exploited the stored fertility of forest

lands, and started on the path of improvement only when forced to take in hand land of such low natural fertility that soil-fertility building was necessary before the land could be farmed. From the latter lands grew the practices of intensive grassland farming which are the basis of the country’s present prosperitypractices which the Dominion must aim to adopt for the improvement of a much wider area of land so that the fertility and production of the major part of the pastoral areas may be improved progressively. The task of land improvement is not easy, and it is a collective as well as an individual responsibility. : If the task of the individual land improver is hard, his reward is great, for what satisfaction can compare with the satisfaction of land improvement (quite apart from the profit which normally accrues from such work)? To the nation the collective responsibility and the rewards are just as great, for

no nation that does not sustain the productivity of its land can long endure. Land and Wealth “Wealth,” says the economist, “consists of all potentially-exchangeable means of .satisfying human needs.” New Zealand obtains its wealth and well-being by exchanging the products of the land chiefly, for the products of industrial Britain, and the exchange is generally approved on . the grounds that each country concentrates on a low cost of production. However, New Zealanders may ask themselves: “Are our costs really low or are we exchanging our land (our capital) rather than the products of the land?” If soil fertility is not being maintained or improved, whence will come the wealth necessary for the well-being of a greatly-increased population?such a population as may be necessary to maintain the security of the country. The history of man’s domination of the land shows far more instances of destruction of soil fertility than. of improvement or even of maintenance. His destruction of the natural plant covering (which under Nature normally has given back to the soil as much as it has taken from it) has generally resulted in fertility depletion, and unless this path is changed the world in future will not be able to feed its peoples, for there are now no New Worlds to exploit. From areas where man has succeeded in maintaining or imi proving fertility certain lessons may be learned, and the lessons, are that methods of land improvement and soil-fertility building must be such as can be carried out by the occupiers of the land and will be of tangible benefit to them.

LEGUMES AND FERTILITY

Land improvement depends largely on the use and improvement of the growth of legumes. White clover is the fertility builder on pastoral land which does not suffer unduly from summer dryness; on land whidh is unduly dry in summer subterranean clover takes its place. Lotus major is useful on moist land in the warmer districts where the soil phosphate level is below that required for white clover. Strawberry clover has its place on rich moist land (particularly reclaimed saline flats) which

is too moist for white clover.

Works imposed by authority of Acts of Parliament or fostered by subsidies are net as likely to succeed as those arising spontaneously from the occupiers or induced from a sense of gaining ultimate well-being for themselves and their country. z Coercion, where it may be necessary, should be a social sanction imposed by the decision of local communities.

The occupiers of the land are the only people who can maintain or improve soil fertility, and they will embark on improvement practices if results are tangible. If the results of their first efforts are successful, other practices or works which may be necessary for soil conservation are likely to be undertaken, perhaps not so ■ much for further tangible benefits as for the protection of the improved asset given by the primary works. '

Soil Fertility Composition and situation are the factors determining the natural fertility of soils, and each is capable of infinite variety. Parent rock and method of formation, rainfall and temperature, age and slope, vegetation and animals all contribute to natural fertility which Man may exploit, conserve, or improve through the management methods he adopts. Thus, though the fertility factors concerned in even one soil are of infinite complexity, the general farming practices which exploit, conserve, or improve fertility are capable of fairly precise definition.

Apart from the modern application of fertilisers and the ages-old use of animal manures and lime, fertility maintenance in the history of farming has really rested on two major practices —the fallow and the use of legumes. The use of both is very old, for Pliny commenting on Virgil noted “ . . . that alternate fallows should be made and that the land should rest entirely every second year. And this is indeed both true and profitable provided a man have land, enough to give the soil repose. But how if his extent be not sufficient? Let him sow next year’s wheat on the field where he has just gathered his beans, . vetches, or lupins or such other crop as enriches the land. For it is indeed worth notice that some crops are sown for no other purpose but as food for others, a poor practice in my estimation.” The real advancement in recent years has been the development of fertility-building and highly-productive pastures, containing clovers and allied plants through .the use of fertiliser and lime. Mixed pastures of grasses and clovers have lessened the necessity for annual legume crops for soil-fertility maintenance.

Wherever people are few and land abundant men rely on the fertility of virgin soils; they take natural pastures, forest, or scrub land, graze or burn and cultivate the land until it shows signs of exhaustion, and then move on, allowing the land to regenerate grass, forest, or scrub. Nomadic peoples, ancient and modern, primitive and highly civilised, have followed this method. The nineteenth- and twentieth-century practices in the New World were possibly more destructive of fertility than those of primitive nomads, for both cropping and grazing were'more intense and sustained.

Settled communities, have had to devise methods which maintain fertility. The basis of medieval European farming was the restorative fallow (the summer fallow for nitrogen, the winter fallow for potash and phosphates) , assisted by hardly-adequate supplies of dung. Backed by sanctions of custom and local authority, the general adherence to a rigid system of crop, pasture, and livestock management did produce a constant but low level ■of fertility maintenance on arable land throughout the Middle Ages.

The- next stage (exemplified particularly in British farming) was the development of modern mixed farming in the eighteenth, nineteenth, and twentieth centuries. Fertility was raised through the inclusion of clovers and turnips in crop rotations, the introduction of fertilisers, and the intimate combination of livestock and crop production. With security of land tenure and freedom of action no sanctions were necessary to enable occupiers to improve land. Each new practice gave tangible results: Improved rotations and fertilisers gave higher crop yields, heavier crops enabled more livestock to be reared and fattened, and the increased number of livestock produced larger quantities of manure, which benefited succeeding crops. Crop and livestock production were increased and farming was made more profitable.

However, these advances did not cover the real scope of land-fertility maintenance, for even at present most highly-developed mixed-farming areas draw on the fertility of extensive pastoral areas where the livestock for fattening are bred and reared. No community can flourish indefinitely on a fixed area of land unless fertility maintenance is reasonably complete on all areas devoted to the production of food. The exhaustion of extensive pastoral areas for the benefit of arable and intensive pastoral areas must in the end contract production.

The extensive pastoral areas of the New World now contribute largely to the meat (through the rearing of store and breeding stock) and wool supplies of the crowded . dependent populations of industry, and these pastures in general are not increasing in productivity. The extensive grazier, commonly merely leasing natural grassland, has done little or nothing to increase fertility; rather, the general experience has been that he has repeatedly burnt and over-grazed and depleted fertility. This depletion of fertility usually has not been deliberate, but has been forced by economic conditions. Many of the normal methods suggested or enforced for conservation example, spelling and cessation of burning—give no immediate tangible results and have to be enforced by coercion..

Commonwealth countries have a fairly common story of depletion and erosion of soils. “In Canada there was evidence of a general decline in soil fertility. Yields were falling, traceelement deficiency, diseases were increasing; the present widespread tendency to soil drifting had not been foreseen when x the land was first cultivated. ... In Australia . . . much depletion of soil fertility had resulted from over-cultivation and over-graz-ing. . . . The increase in population in India was producing a very serious

situation with regard to depletion of soil resources. Nobody had a clear picture of how much damage had been done by. erosion. . . . South Africa was mainly pastoral and most of the pastures were natural. It was essential to discover conservative systems of intensive farming. Legislation had been enacted putting the responsibility for proper land use on the farmers. The State assisted with subsidies and only intervened by expropriating the land in the last resort. . . .In parts of Kenya large areas of fertile forest land had reverted to desert conditions within living memory. ...” (1) . In New Zealand settlers burnt and over-grazed (or allowed rabbits to over-graze) the natural pastures, exploited the fertility of the forest lands, and started on the path of fertility building only when it was necessary to take in hand land of low virgin fertility, and the practice of topdressing grassland was developed. Topdressing is one of those practices that adequately fills the requirements for land improvement: It can be done by the occupiers of the land; it gives immediate tangible results; its development requires no coercion; and from it flow other desirable farm practices and improvements. ■

BENEFITS OF TOPDRESSING

1. From a summary of discussions on problems of land utilisation and conservation, the Royal Society Empire Scientific Conference, 1946, Volume 11, pages 217 and 218.

So far topdressing has been confined mainly to 4 to 5 million acres of flat and undulating land, and this land has provided the great increase in supplies of meat, wool, and dairy produce in the past 25 years. Very little has been done to mitigate the depletion of fertility on the 10 million acres of surface-sown grassland and 13 million acres of native tussock grassland. Experience has proved that in the higherrainfall areas topdressmg accompanied by the oversowing of clovers will improve the carrying capacity and fattening ability of large areas of surface-sown grassland. On such areas ‘Xa'rv'stVm fertJitv bS MiSg and P™ ar y step From it will flow Ither necessary conservation methods in the con t rc j o f erosion, but without the nritnarv ■npartiop to pivp tancfible results the secondary practices will be “SsTdie? Fo/thTl qiihqirh’pq and coercion For the 13 m jijj on acres of native pasture the best that can h oped f or a t the moment . g conserva tion through rabbit destrucregulated grazing and burning, and ’ spelling. None of these will start upward spiral of fertility building and they can secure only conservation, path to improvement may be found later in suitable pasture species which will conserve or increase ferfiiifv arir i ofTpp increased ■ carrvinE W the reward for their introcapacity as the re war a lor t e r miro duction.

FARMING SYSTEMS OF THE NORTH ISLAND

Dairy farming in the North J Island is confined mainly to flat i and undulating land in the \ higher-rainfall areas where I permanent pastures of the peren- ; nial ryegrass-white clover type J I have been established after ■ I ploughing. Fat lamb production ( I (intensive sheep farming) is ) carried out on similar land, but J dominates dairy farming in the 1 lower-rainfall districts. The j more extensive types of sheep j farming are found on the surface- I sown hill country. Extensive i sheep farming (producing wool I I and store and breeding stock) I occurs on pastures of browntop I and danthonia where clovers are I absent; semi-extensive sheep ; farming (producing a proportion I of fat stock as well as store and I breeding stock) occurs on hill I country where clovers accom- I pany grasses in the pastures f which have been surface sown. |

|* » * | Dairy farming ) | Fat lamb raising KgO Extensive pastoral farming (store sheep and cattle) [<ttl Orchards, gardens, L —"and specialised crops I 1 Undeveloped land (bush, scrub, *— 1 and mountainous areas) and lakes

In the past the increase in population in New Zealand has followed fairly closely increased primary production, and if for security or other reasons the development of a population two or three times as great as at present is desired, it is only logical to assume that the volume of primary production must be increased in similar proportions.

At present about 30 per cent, of total meat production, 20 per cent, of butter production, and 5 per cent, of cheese production are consumed in the country, and half the wheat requirement is imported. With three times the present population only a small volume of food exports would be available to exchange for necessary imports unless the production of primary products kept pace with the increased population.

There is no doubt that the Dominion’s lands are capable of giving ultimately twice the present flow of food, fibre, and forest products, provided fertility building is widened to embrace gradually all the potentially-productive lands in the Dominion.

Land Under Occupation New Zealand is a pastoral country. Of the 43 million acres under occupation, about 31f million acres consist of pasture lands of various types and only a little more than 1 million acres grow annual crops, of which about half are cereals and half fodder crops. The detailed classification of occupied land as at January 31, ' 1947, given in the following table excludes areas within cities and boroughs and holdings smaller than 1 acre:—

LAND UNDER OCCUPATION, 1948-47 (thousands of acres) Sown pastures .. .. .. 18,077 Tussock grassland .. .. 13,827 Annual crops . . .... 921 Fallow land . . . . .. 124 Orchards and gardens .. 113 : Plantations .. .. .. 870 Phormium tenax .. .. 34 Fern, scrub, and forest .. 7,425 Barren and unproductive .. 1,709 Total area occupied .. .. 43,100

Sown pastures consist of land sown to grass after being ploughed or after being surface sown following the burning of natural forest, fern, or scrub. Though no recent data are available of the areas sown by each method surface-sown pastures probably cover 10 million acres and pastures on cultivated land 8 million acres. :

The pastures sown after ploughing are used chiefly for meat and milk production and are on flat and undulating land. In the higher-rainfall districts the pastures are permanent or long rotation and in, the lowerrainfall areas short rotation. A feature of these pastures is that the swards generally consist of a mixture of grasses and clovers, and the clovers are essentially the fertility-building constituent. Where ploughable lands in the higher-rainfall areas are not naturally fertile enough to grow clovers the custom has been to topdress with fertilisers, lime, or both to raise the fertility to clover level, thus providing for the subsequent rewards of clover fertility in increased carrying capacity.

The surface-sown pastures, on the other hand, are generally deficient in

clovers and most of the area is devoted to the production of wool and of store and breeding stock which are transferred to the flat and undulating lands for meat production. However, where the land is naturally fertile or has increased in fertility through being topdressed the pastures consist of a mixture of grasses and annual or perennial clovers and fat as well as store stock are produced from them. Situated generally on steep and hilly land, these surface-sown pasture lands have suffered from sheet and slip erosion over fairly large areas, and gully erosion is a problem on certain restricted areas. In the high-rainfall areas the tendency for the land to revert to secondary growth is strong, and a constant struggle must be maintained to suppress it by grazing management, cutting and burning, and resowing to grass.

The pastures of tussock and other native grasses are on the hilly and mountainous country in the lowerrainfall areas east of the main divide in the South Island and are used for extensive pastoral farming. These pastures evolved in the absence of grazing animals and in the natural state were not particularly palatable to sheep. However, the grazier found that the fresh growth which followed the burning of the tussocks was eaten readily by sheep, and in the earlier years of settlement indiscriminate burning, overstocking, and the destruction of plant cover by rabbits led to serious deterioration and in places to depletion of vegetation. The development of methods for the improvement of the plant cover and regeneration of the native tussock remains a major problem.

The production of field crops is restricted mainly to the flat and undulating land in the lower-rainfall and colder districts where summer or winter fodder crops or both are required to supplement pastures for livestock feeding. The common crop rotations include cereal, pulse, fibre, food, and seed crops, as well as summer and winter fodders. After 2 or 3 years in crop the land is sown to pasture, which may remain down for 3 to 5 years, or longer on heavier soils or in higher-rainfall areas, and while under grass the land regains the fertility lost during the period under crop. Systems of Farming The 18 million acres of sown grass, 13J million acres of tussock grassland, and J million acres of root and green fodder crops support nearly If million dairy cows in milk and 3 million other cattle as well as 20f million breeding ewes. Systems of farming conform to the productivity of the pasture lands and comprise the following types: — Type of Farming Very extensive sheep farming Extensive sheep farming Semi-extensive sheep farming

Semi-intensive sheep farming

Intensive sheep farming (a) Permanent grass (b) Grass and fodder crops (c) Grass and fodder and cash crops Dairy farming

There are, of course, farms which combine more than one type of management. Dairying may be combined with sheep farming, and on a sheep farm intensive pastoral farming may be practised on one section and extensive farming on another.

The general locations- - each type are given in the maps on the opposite and following pages. Very extensive sheep farming is carried out on the high mountainous tussock grassland of the South Island and extensive pastoral farming on the lower tussock grassland areas and over the major part of the surface-sown grasslands of the North Island. As pastures improve, fat as well as store and breeding stock are produced, but really-intensive grassland farming is confined mainly to the flat and gently-undulating country. The term arable mixed farming is commonly used where intensive pastoral farming is combined with the production of cash crops.

The sheep farmer usually grazes cattle as well as sheep, particularly on the sown grasslands of the North Island, for cattle are necessary to maintain pastures in a suitable condition for sheep. Surplus summer growth must be eaten down in autumn to keep pastures suitable for sheep, and on hill country cattle are necessary to crush fern and other secondary growth.

The different types of sheep farming are closely integrated: The extensive sheep farmer supplies the breeding ewes, store lambs and wethers, and store cattle to the intensive grazier. The trend during recent decades has been toward a marked improvement in carrying capacity on the intensivelyfarmed areas and a stationary or declining carrying capacity on the extensively-farmed areas. This tendency is so marked in certain areas that intensive pastoralists have had to turn to breeding at least part of their replacement stock.

Land Classification

A discussion of methods of land improvement is facilitated if land is first classified. Unfortunately, there is no general uniformity in methods of classification because of the diversity of emphasis which classifiers have placed on the physical, social, and economic factors involved in the definition of land classes. For the land improver the most useful classification is one based on the plants which the soil will produce and which may be converted into marketable products. In New Zealand pasture plants are a useful index of fertility and intensity of farming, and of pasture plants clovers are possibly a better index than grasses. The pastoral lands of

Products Wool Wool and store and breeding stock Wool and store and breeding stock, plus a proportion of fat stock Wool and fat stock with a proportion of store and breeding stock Wool and fat stock

Whole milk, cream, pig meat, and store and fat cattle

[jxj] Dairy farming' |=j Fat lamb raising iwwm Extensive pastoral farming Wla (store sheep and cattle) ■ Very extensive pastoral farming (principally for wool production) ]| Htiil Arable and mixed farming i f . t t 'i Orchards, gardens, I T tJ and specialised crops r- —I Undeveloped land (bush, scrub L—— and mountainous areas) and lakes

Native tussock pastures occupy more than 13 million acres of land in New Zealand. Very extensive sheep farming . (for wool production) is carried out on the high mountainous tussock pastures of the South Island and extensive sheep farming (producing wool and store and breeding stock) on the lower areas. On flat land in the higher-rain-fall areas intensive sheep farming (for fat lamb production) and dairy farming are based on permanent or long-rotation pastures; in the lower-rainfall areas short-rotation pastures take the place of permanent or long-rotation ones, and fodder and cash crops (arable mixed farming) figure largely in programmes of farm management.

New Zealand may be divided broadly

into the classes set out in the table on this page, depending on the use to which they are put, certain pasture plants they support, and the topography of the land. (2) Clovers have been used as the basis of classification, for land improvement depends mainly on using and improving the growth of legumes. Though advancement in the science and practice of farming has provided the means of doing this on an ever-increasing variety of soils, the replacement of legumes' with cheap synthetic nitrogenous fertilisers has not yet been found practicable, though that may be the next stage in advancing pasture production beyond that at present attainable with a combined sward of grasses and clovers. Each of the land classes outlined is composed of numerous soil types, and each soil may require some modification to be introduced to a general land improvement method . applicable to the land class. Topdressing with fertilisers and lime is a general landimprovement practice, but soils differ in their need for phosphates, potash, lime, etc., and the details of the practice must be made to suit soil requirements. The main soil types in New Zealand have been named and mapped and their natural fertility level studied, and land improvers should discuss their plans with local instructors of the Extension Division of the Department of Agriculture, who are in a position to advise on details of soil and land treatment.

2. “Land Classification in New Zealand,” a paper by L. I. Grange and P. W. Smallfield delivered to the Seventh Pacific Science Congress. ■ .

USE CHIEF PASTURE CHARACTERISTIC TOPOGRAPHY Meat and milk I. Water grasses , Flat; subject' to periodical flooding 2. Strawberry clover Flat; reclaimed tidal 3. White clover permanent Flat and undulating 4. White clover permanent when land is top- Fiat and undulating dressed and/or irrigated or drained Meat 5. White clover permanent, but not vigorous Hilly and steep 6. White clover permanent only if topdressed, (a) Elevated, flat and , and improvement work more costly than rolling, or hilly and on 4 because of topography (a) or special steep; (b) flat and soil condition (b) rolling 7. White clover lasts only 3 to 5 years with or without topdressing (a) Subterranean clover with topdressing Hilly and steep (b) Low yields of annual crops and sub- Fiat and roiling terranean clover more suitable than white clover ' (c) Medium yields of annual crops Flat and rolling (d) High yields of annual crops Flat and rolling Meat, store stock, and 8. Annual grasses and clovers \ Fiat wool ■ . . ' Store stock and wool 9. Clovers absent and topdressing not feasible z . (a) Danthonia-browntop . Hilly and steep (i) With no erosion - (ii) With erosion (b) Native pastures : Hilly and steep (i) With no erosion , . (ii) With erosion ' ~ Wool , 10. Native pastures Mountainous

Class 1: Land Subject to Periodical Flooding (Water Grasses) The land improver should be careful to assess the value of the pastures which land subject to periodical flooding will produce naturally against the changes in vegetation which may occur if the incidence of flooding is altered. Many attempted improvement works on such, land have resulted in making conditions unsuitable for water grasses and still not suitable for moist- or dry-land pastures. . Attempts to change natural ponding areas from floating sweetgrass to perennial ryegrass and white clover may result in a waste of tall fescue or manuka if the drainage or stop- ‘ banking works are inadequatethat is

if, though winter flooding is prevented, the drainage outfall is not sufficient to reduce the water level in the soil. Land subject to periodical flooding is present in the lower reaches of rivers and streams of all sizes. Large areas of such land exist in the lower Waikato and Manawatu, but the average farmer is concerned mainly with small areas in stream valleys, in which flooding may vary from periodical floods of short duration to total submergence for 4 or 5 months. Conditions are too wet for clovers, but soils comprising this class of land are naturally rich in organic matter and with a high summer water-table are capable of providing abundant? summer grazing from water grasses. The

common species of water grasses used are reed sweetgrass (Glyceria aquatica), floating sweetgrass (Glyceria fluitans) , mercer grass (Paspalum distichum), and reed canary grass (Phalaris arundinacea) where winter flooding is prolonged. On areas where winter flooding is not so prolonged meadow foxtail (Alopecurus pratensis), rough meadow grass (Poa trivialis), Yorkshire fog (Holcus lanatus) , and paspalum (Paspalum dilatatum) are frequently associated with the former grasses. „ . „ , ~ ~ , Each grass has its own particular - requirements. Mercer grass and paspalum are confined mainly to the warmer areas in the Auckland Land Districts. Floating sweetgrass grows in areas where the flood waters keep moving gently, and reed sweetgrass thrives where the flood waters are more or less stagnant. • Mercer grass, grows most abundantly in the flooded areas of the' lower AVaikato, where it survives several months of complete immersion. The grass is extremely palatable, but as it is a shy seeder it must be propagated by cuttings. The grass is cut by frosts and survives only when winter floods give a complete cover to the plants. Pasp alum dilatatum will stand comnlete immersion for onlv relativelvshort periods and is really a dry-land rather than a water grass. ... Floating sweetgrass also will g not . stand at severe flooding as mercer grass or reed sweetgrass; it thrives particularly when the water is moving and the flooding not so severe as to prevent the plant’s long, trailing stems reaching the surface of the water. Over wide areas of winter-flooded land reed

sweetgrass is quite suitable; it is not as palatable as mercer grass or floating sweetgrass, but produces a great bulk of summer fodder which is eaten readily. All these water grasses will grow in drains, and in certain situations may cause considerable interference with the free flow of drainage water.

There is little doubt that utilisation of flooded areas with water grasses is frequently more economical than improvement through costly stop-banking and drainage and pumping works, particularly where the flooded area is merely a portion of a dryland farm and through the introduction of water grasses can be made to produce valuable summer feed at slight expense.

Class 2: Wet or Saline Land (Strawberry Clover) , Strawberry clover (Trifolium fragiferum) is a most valuable clover on land which is too wet or too saline for white clover and is * used most advantageously in the reclamation of the tidal estuary lands of rivers and harbours. ' The reclamation of tidal land is a long-term project and requires the erection of fairly costly works, consisting of stop-banks, floodgates, drains, and, frequently pumping plants, but the land usually is highly productive when grassed, and more tidal reclamation works could add many thousands of acres of useful grassland to the pastoral area of the Dominion. In the reclamation of a tidal flat stop-banks must be erected and are raised from material obtained from a

ditch which runs parallel to and on the inside of the stop-bank and which ultimately serves as the main drainage canal for the reclaimed area. The material for the ditch is moved forward a few feet and built into a bank, the height of which depends on . the maximum rise and fall of the tide but should be at least 2 or 3ft. higher than the level of maximum tides. The stopbank may require revetting with stones or brush to prevent wave erosion in exposed positions and should be planted with earth-binding grasses. in the northern districts buffalo grass and kikuyu grass are very suitable for this purpose. Drainage outlets through the stop-banks must be provided by flood-gates with concrete or timbered supports or by concrete pipes The rapid removal of drainage water is greatly facilitated if flood pumps are installed to lift water away between tides. After the tidal waters have been excluded from the area the next step j s t o provide adequate internal drainage by open and covered drains so that the rain may wash through the so and carry away the surplus salt, Three to 10 vears mav nass before reclamed tidal land “ fit for grassing The first indication that the salt content is being lowered is the appearance of sea aster (Aster subulatus) plants, and when these are followed by a fairly general growth of Canadian fleabane (Erigerori.canadensis) the land is usually fit for grass, Strawberry clover is the essential pioneer plant in pasture establishment; bas tremendous powers of spreading over the ground by means of long stolons, and one plant ultimately will cover many square yards. The usual

pasture mixture consists of perennial .ryegrass and strawberry and white clovers, with the addition of paspalum in the warmer districts and cocksfoot .and timothy in the colder. Grass growth depends on the successful -establishment of strawberry clover and normally is not satisfactory until strawberry clover has colonised the whole area, but when this has •occurred very highly productive milkand meat-producing pastures are secured. * As well as on tidal flats, on large areas of moist land in river bottoms and swamps strawberry clover grows •exceedingly well. Where such areas occupy tire major part of a farm the tendency is to drain the land so that all-year-round stocking is possible and to change the sward from strawberry clover dominance to white clover ■dominance. However, where such flats are a minor part of a farm it may be more desirable to leave the land moist and use it for late-spring and summer .grazingfor instance, on sand-dune country where moist flats suitable for .strawberry, clover are interspersed with higher land suitable only for subterranean clover. Class 3: Flat and Undulating Land (White Clover Permanent) Land on which white clover is permanent and vigorous without special soil treatment occurs chiefly •on alluvial river flats and terraces and •consists of moist, fertile soils, generally used for dairying and fat-lamb production. Excessive winter soil ■moisture is usually the limiting factor in stocking and pasture utilisation, and -most areas require thorough drainage, -either with moles or tiles or with a

combination, to reduce winter poaching and to control rush growth. Without such improvement large areas, such as the Hauraki Plains, cannot be utilised to full advantage unless the rich alluvial land is used in conjunction with dry winter run-off country. Winter poaching is responsible for reducing production over large areas; poaching not only destroys the pasture turf and allows the ingress of weeds, but also is destructive to the soil structure and causes the land to harden and crack in dry summer weather. Rolling the sward after winter poaching to revivify the turf is a practice worthy of extension, but it is. only a palliative and cannot replace thorough drainage as an ultimate necessary work for land improvement. Over large areas rushes occupy a considerable proportion of the land surface; they are encouraged by . wet winter conditions and close and continuous grazing. Thorough drainage, the re-establishment of a vigorous sward, and controlled rotational grazing usually are x necessary for rush control. The conditions which occur in soils on which white clover is permanent and vigorous are worth close study, for the chief task of the land improver is to raise low-fertility soils to the fertility status required by white clover. The brief comments made about white clover land have stressed the necessity for fertility and moisture; the soils are rich in plant food and are moistfrequently too moist in winter for the full utilisation of the feed produced. Moisture and high fertility are necessary because white clover is a very shallow-rooted plant

and is intolerant of summer dryness or winter flooding. When the white clover plant germinates it has a taproot, as red clover has, but after a year or 18 months the taproot disappears and the plant depends on shallow roots which spring from' the plant’s stolons. Hence soils rich in plant food but dry in summer do not maintain permanent white clover, and when white clover is used in the pasture it remains vigorous only for 1 or 2 years, as is common on the wheat-growing lands of Canterbury, though it may be maintained through lax summer grazing to allow annual reseeding. Providing the rainfall is sufficient (as it is in most parts of New Zealand) and the soil retains moisture in summer, the fertility may be raised to white clover standard through the application of fertilisers and lime. The treatment required will depend on the soil: It may require lime, it may require phosphates, or it may require. potash either alone or in combination. However, if the soil is dry in summer, it cannot be made to carry permanent white clover without irrigation, and subterranean clover must replace it as a pasture clover. Class 4: Land which Requires Fertility Building- to Maintain Permanent and Vigorous White Clover The application of fertilisers and lime and the provision of drainage works and in certain areas of irrigation may be necessary to bring land to a fertility level suitable for the permanent . and vigorous growth of white clover. The most important improvement method has been liming and phosphatic topdressing, and this practice has raised the carrying capacity of millions of acres of pasture land

sown after being ploughed. The total area of grassland topdressed in the Dominion has risen from 1J million acres in 1927 to 4| million acres in 1947.

FERTILISER AND LIME USAGE, 1927-1947 Total Total area production topdressed Total fertil- of agricul- with fertilisers iser usage tural lime and/or lime (thousands (thousands (thousands Year of tons) of tons) of acres) 1927 .. 292 1,521 1928 .. 392 183 1,952 1929 .. 465 222 2,758 1930 ..526 205 2,651 1931 .. 403 171 2,871 1932 .. 360 202 2,454 1933 .. 403 192 2,438 1934 .. 376 262 2,249 1935 .. 373 289 2,684 1936 .. 426 317 2,882 1937 .. 503 411 3,326 1938 .. 611 482 3,874 1939 ... 614 391 4,017 1940 .. 673 594 4,187 1941 .. 699 728 4,649 1942 .. 502 613 4,212 1943 .. 362 753 3,470 1944 .. 285 904 3,370 1945 .. 430 813 3,646 1946 .. 507 930 3,653 1947 .. 620 1,021 4,259

Topdressing with phosphatic fertilisers began in the early 1880’s in the Waikato, where the rainfall is high and the soils are of good moistureholding capacity but naturally deficient in phosphates. Conditions generally were unsuitable for the production of cereals and rotational farming was unprofitable. Intensive grassland farming was impossible, without the raising of the fertility level of the soils. Experiments showed that topdressing with superphosphate, bone-

dust, and phosphatic guanos brought about a vigorous white clover growth which might be used as the basis of milk- and meat-producing pastures. Basic slag became an important fertiliser for topdressing in the - early 1900’s, but was largely displaced by superphosphate, after 1920. Most soils, except the most immature, require lime in addition to phosphates, and lime usage rose from less than 200,000 tons in the 1920’s to more than 1,000,000 tons in 1947. Theoretically, liming where necessary should precede or accompany phosphatic dressings, but in the history of land improvement phosphates generally have been used first and have provided the revenue for liming. Young and unleached soils are very responsive to superphosphate, but on mature and leached soils liming is necessary before superphosphate is effective; it was on such soils that large quantities of basic slag and rock phosphates were used effectively in the absence of liming, though on most soils they would have been more effective with lime. Even if not fully efficient, they gave very payable results in increased clover growth, and part, of the revenue earned was then reinvested in liming and more phosphatic topdressing. In addition to lime and phosphates, potash is required by certain soils to maintain vigorous white clover growth; important potash-deficient areas are Waihi and parts of Taranaki and the Waikato. Potash has an effect similar to that of phosphates and lime: It enables white clover to grow vigorously, and if white clover grows vigorously, the grasses will also grow.

Thus, on most soils of this land class a study of both fertiliser and lime requirements and the mois-ture-holding capacity of the soil is necessary. Therefore the land improver must study carefully the soil he intends to improve and first he certain that the quantities of fertilisers and lime required for improvement will give an economic return and that the mois-ture-holding capacity of the soil is satisfactory. Locality experience (amplified by the results of Departmental trials) is the best guide in this direction.

Apart from the lands capable of improvement through irrigation, the two main areas of land in class 4 awaiting the hands of land improvers are, first, land now carrying pastures below the production level which is possible through the use of improved strains of grasses and clovers and not excessive applications of lime and fertilisers; and, second, land in scrub and fern.

Very large areas of the Dominion’s 8 million acres of grassland sown after ploughing were established before supplies of Certified pasture seeds were available, and large areas (up to a third in intensively-farmed districts) are not capable, even under regular topdressing, of maximum production unless the swards are renewed and high-producing strains of perennial ryegrass and white clover are introduced. It is from these pasture lands that an immediate increase in primary production might be obtained through pasture renewal.

There are three main renewal methods: Surface cultivation followed by the broadcasting of seed and fertiliser; ploughing and direct reseeding; and sowing to grass after a fodder crop. Again the type of soil largely determines the most satisfactory method. Surface cultivation and seeding succeeds only where the surface soil when lightly broken affords a satisfactory seed-bed; it is most successful in light, moist soils, but may not be at all satisfactory on pastures with a complete turf which the surface cultivator does not open up sufficiently or where the surface soil is hard and cultivation is inadequate. Direct reseeding after ploughing is quite satisfactory if the work of seedbed preparation has. been thorough and the seed-bed has consolidated sufficiently to allow a good strike of white clover. If the seed-bed is not consolidated, white clover will not establish, and without white clover perennial ryegrass will not be vigorous; where the white clover strike has been poor the pasture may require 2 or 3 years to regain its former productivity. On light land seed-bed consolidation is assisted greatly by rolling of the land on the furrow after ploughing and rolling well before and after sowing; on heavy land natural consolidation must be allowed and a complete summer fallow is usually necessary to bring this about.

The most general and satisfactory method is to plough and take a fodder crop for winter and early-spring feeding and either to spring sow (where conditions are suitable) after surface working, or to plough, summer fallow, and sow early in the autumn.