Lucerne

New Zealand Journal of Agriculture, Volume 71, Issue 2, 15 August 1945, Page 165

Lucerne

T UCERNE is a forage crop of such outstanding merits over a wide range of conditions that it should be used much more freely in New Zealand farming than is the case at present. The area under lucerne in the Dominion is, relatively small, the statistical returns for the past 16 years being as follows: —

This is in marked contrast with many countries where the area in lucerne has been trebled over the same period.

New Zealand Experience

Experience with lucerne in New Zealand has extended over very many years. It has covered a wide range of conditions, and it has been sufficient to provide reliable evidence that more extensive use of lucerne is well warranted throughout the greater part of the Dominion. At times authorities seem to incline to the belief that lucerne is suited only for relatively dry climatic conditions, such as would occur, for example, in localities with less than 30in. of annual rainfall. This belief that the usefulness of lucerne is restricted to relatively dry conditions probably is partly due to the fact that the merits of the crop are apt to be particularly emphasised under dry conditions. For instance, when droughty conditions prevail in Canterbury, Marlborough, or Hawke’s Bay, then it is that the special value of an area of lucerne becomes particularly apparent, for under such conditions it is likely to be the only crop making fresh vigorous growth. But New Zealand experience has definitely shown it is unsound to hold that the use of lucerne should be restricted to the drier farming areas. In proof of this it need only be mentioned that for years lucerne has given markedly

1 profitable returns in parts of South Taranaki, and that highly-profitable areas are to be found in parts of the Auckland and Wellington Provinces in which the rainfall is well in excess of 30in. New Zealand experience has further shown conclusively that lucerne is not at all as exacting in its requirements as some seem to believe. Indeed, it has been grown successfully on practically all types of well-drained soils except peaty soils. Our experience in this connection does not differ from that of other countries. As evidence of this we find Wm. Lawson in the “Journal of the Ministry of Agriculture” (England) saying: “Lucerne is suited to a wide range of soils; drainage is most important, and a well-drained soil and subsoil are absolutely necessary.” Again, Bulletin 1283 of the United States Department of Agriculture, states: “The wide distribution of alfalfa (lucerne) in the world indicates a remarkable adaptability to climate and soil.” Valuable Features The excellence of lucerne as a forage crop arises from a combination of factors, including its high yield, high nutritive value, reliability during

crucial seasons, low cost of production, and its capacity to improve soils. High Yield .—Over a wide range of conditions in New Zealand lucerne suitably managed will provide three to five “cuts” annually for a series of years. Each cut will contain on the average from 5 to 7 tons of green forage per acre. Hence an acre of lucerne will yield annually in the vicinity of 25 tons of green forage. Frequently the annual yield is in excess of this. .As 25 tons of green forage represents a yield of about 6-1 to 7 tons of hay per acre, the annua] production of lucerne is high. High Nutritive Value.lnvestigational work in New Zealand agrees with similar work overseas in showing that the lucerne herbage is exceptionally nutritive, and that it is especially rich in those substances most apt to be lacking in the rations of stock, particularly of the . highest-producing animals. It is rich in phosphates, lime, and protein, all of which are of practical moment in animal production and particularly in body-building. The nutritive components of lucerne are also highly digestible, especially when the crop is utilised before it has become woody. Hence, green lucerne is very valuable in dry seasons during late summer and autumn, when other succulent material is scarce, to pro-

vide the necessary fresh digestible material required by cows in milk. Lucerne hay, because of its high nutritive value, may also be suitably used to supplement feeds which are inferior or low in their content of substances in which lucerne is relatively rich. For example, lucerne hay and roots may be made to constitute a wellbalanced ration, the lucerne supplying the deficiencies of the roots. Reliability During Crucial Seasons.— .One of the most valuable features of lucerne arises from the. fact that established lucerne, because of its deeplypenetrating root system, is well fitted to withstand periods of drought. Hence, lucerne may safely be relied upon to make vigorous nutritive growth when practically all other crops fail. Lucerne is outstanding in respect to the quantity and quality of its yield, but if it .

were not so, and if it were only normal in these respects, its reliability during crucial seasons would be a weighty factor in its favour in comparison with other forage crops that compete with it. in popular usage. One is more likely to undervalue than to overvalue the reliability of lucerne during crucial seasons. . The relative values of a lucerne crop which may be relied upon for forage during unfavourable seasons and other crops which may not be so relied upon . cannot be ascertained merely by comparing the ‘ crops in respect to the annual yield of nutritive matter. Hence, even if it were true to say that an acre of, say, grass, would under certain circumstances produce annually as much nutritive matter as an acre of lucerne, it would not follow neces- . sarily that the products of the grass

and of the lucerne were of equal cash value. The reliability of the lucerne during critical seasons would almost always swing the balance in its favour. Low Cost of Production.— Forage from lucerne is ordinarily characterised by low cost of production. Low cost arises as the combined effect of > three factorsthe heavy yield of the crop, its reasonably low cost of establishment, and its relatively long life as a producing unit. The matter of yield has already been discussed. For'some obscure reason it is frequently assumed that it is a very costly matter to establish a crop ' of lucerne. In view of all the facts it is difficult to know why this idea is held. Under ordinary circumstances, apart from the cost of lime, it should be no more expensive to establish an acre of lucerne than to sow down the same land in permanent pasture. The preparatory cultivation and manuring needed for the one would serve equally well for the other. The only difference would be in respect to > cost of seed, and 15 or 161 b. of lucerne seed is not substantially different in cost from the pasture seeds for an acre. Normally lucerne lasts as a profitable crop for many years fact, at times it becomes practically permanent. But should its life be limited to five or six years, as sometimes happens, it will even then usually have' proved a handsomely profitable proposition. This is because the initial cost of establishment, when spread over so many years

of good production, represents but a slight overhead charge on the gross returns.

Capacity to Improve Soils.— The fact that lucerne, being a legume, has the power of utilising the nitrogen of the atmosphere is a feature which commends it. This fact means that usually lucerne, instead of calling for the use of expensive nitrogenous manures, actually builds up the content of nitrogen in the soil. This, together with its deeply-penetrating root system, means that lucerne tends to build up rather than to exhaust soil fertility.

Soil and Situation

Deep, fertile, open, well-drained loams are undoubtedly best for lucerne. On account of the deep habit of its root system lucerne does not thrive on a soil which because of bad drainage or impervious subsoil does not allow of deep root penetration. Good surface drainage and under-drainage are both necessary. Land selected for lucerne should be. either of high productivity naturally, or made so artificially by the application of suitable dressings. . The marked success which characterises lucerne in Central Otago may definitely be linked with the fertility of the soils.

In selecting land for lucerne it should be remembered, also, that lucerne is not well fitted to battle against weeds in its early life. Hence it is not advisable to select land which is known to be infested with seeds of annual weeds, or with parts of twitchy perennial weeds, unless these have been weakened by previous cultivation or cropping.

Because of the injury weeds may cause lucerne in its early delicate stages, it is at times good practice to select for a new area land which has been down in grass for many years, and to plough it deeply once only. A preliminary skim ploughing, or alternatively, a severe discing, to secure disintegration of the turf may often with advantage . precede the deep ploughing, but a second deep ploughing is inadvisable, because it would bring to the surface again the numerous weed-seed population which was buried by the ; first ploughing and which will remain dormant and harmless provided it is not brought back to the surface. Apart from weed considerations, the establishment of lucerne on a soil freshly broken up from old pasture is at times of advantage because such a soil possesses a certain amount of accumulated fertility likely to be of value to the lucerne. A pasture infested with twitchy weeds should as a rule be avoided when it is intended to sow lucerne immediately after grass.

It is almost courting disaster to sow lucerne on land which recently has been under the plough unless the crops preceding the lucerne were kept

free from weeds, or unless some way of freeing the land of weeds, such as suitable cultivation, has been adopted. Provided lucerne can become reasonably well established it will frequently battle successfully even against persistent vigorous weeds. For instance, at times lucerne successfully combats Californian thistle, but for this to happen the thistle must have been weakened sufficiently by previous cultivation to allow of the satisfactory establishment of the lucerne. On very light soils deficient in humus it may be advisable to precede lucerne by a crop such as lupins, red clover, tares, or oats, which, used for green manuring, builds up the soil fertility. Because of its better surf ace . drainage, land which is slightly undulating is at times preferable to that which is quite level. It is also of value to have a lucerne field sheltered from the prevailing wind. Preparation of Seed-bed Lucerne seed being relatively small the preparation of the seed-bed becomes of prime importance. To enable the seed to be sown at . a uniform depth and not too deeply, a fine, firm seed-bed is necessary. To obtain this a liberal amount of preparatory cultivation, commenced well ahead of the time of seed sowing, must be carried out. Fortunately, the cultivation which will most readily produce a suitable soil tilth will also tend to destroy weed seedlings that develop on the surface layer of the soil during the period of preparation. If lucerne is to follow old pasture it is usually advisable to skim plough the land in the autumn or early winter,

and to plough the land in the late winter or early spring to a depth of sin. or 6in. For this deep ploughing, if autumn ploughing has not been carried out, it is as a rule advantageous to use a skimming attachment designed to remove the surface slice and place it in. the open furrow. This not only buries surface weed seeds, but also assists 'in the production of the desirable firmness in the seed-bed. Where lea land has been ploughed the furrow slices should be rolled with a Cambridge roller to ensure satisfactory consolidation to a reasonable depth. Subsequent preparatory • cultivation should be fitted to produce a fine, firm seed-bed without disturbing the original surface layer.

Radio Broadcasts

RADIO talks to farmers will be given from Station IYA, Auckland, at 7.15 p.m. on . the following dates :— September 3. —“Young Farmers’ Club Session,” to be given by a member from the King Country clubs. . September . 10.“ Control of Cress in Pastures in the Bay of Plenty,” by Mr. A. V. Allo, Instructor in Agriculture, Department of Agriculture, Tauranga. September 17.“ Why the Farmer Should Use Certified Seed,? by Mr. J. H. Claridge, Seed Certification Officer, Department of Agriculture, Wellington. September 24.—-“ Young Farmers’ Club Session,” to be given by a member from the Eastern Bay of Plenty clubs.

When lucerne is to be sown in land not newly broken out of pasture the previous crops should be fitted to minimise the danger of weeds. Over wide areas mangolds or potatoes followed by a green crop may be utilised to leave the ground in suitable . condition for lucerne. To obtain this result the root crop must be kept thoroughly clean, and it is desirable that the following crop, such as rape, kale, oats, or barley, with or, without tares, used as greenfeed, should be a heavy one, as a result of liberal seeding and manuring, in order that it may smother any weeds that appear. Such a crop would need to be consumed early enough to admit of ploughing of the land in October. As in the case of lea land, the purpose of cultivation subsequent to ploughing should be the production of a fine, firm seed-bed. As a rule, for several weeks prior to seeding, all land being prepared for lucerne should be frequently cultivated to a depth of about 3in. Such cultivation brings batches of weed seeds to the surface, where they germinate and are

then easily destroyed by the following cultivation. Further, such cultivation keeps the land bare of vegetation, the presence of which might lead to the eggs of the grass-grub being deposited on the land to the eventual detriment of the lucerne seedlings.

Liming Probably no other crop responds so well as lucerne to a liberal supply of lime in the soil, and it is safe to

assume, unless there is definite evidence to the contrary, that profitable returns will be obtained from liming land for lucerne. Central Otago is an exception, to this rule, and there liming for lucerne generally is not justified. Lime may as a rule be applied with advantage before the final cultivation preceding seed sowing. It is customary to apply about 1 ton of ground limestone to the acre, but smaller

amounts are also used. If price warrants it, or if cost of transport is substantial, burnt lime used at' half the above-stated rate may suitably replace the ground limestone. In many places periodical liming of established fields of lucerne is considered advisable, and there is a tendency to favour dressings of a few hundredweights per acre at relatively frequent intervals instead of dressings of a ton or more at longer intervals.

Sowing the Seed

To secure the required firmness, of seed-bed the land should as a rule be rolled prior to seeding, but it may be necessary to roll more than once.

'Under cold conditions vigorous development of seedlings does not occur, so as a rule there is nothing to be gained by early sowing while the soil is still cold. Generally, best results are obtained by sowing during the latter part of November or December. At times in favourable seasons really good results are obtained by earlier sowing, but there is as a rule no justification for' taking the risk, unless it is expected that dry conditions will be experienced in the late summer before a crop sown late in November or in December has become securely established. At times autumn sowing is practised. One reason for autumn sowing is the avoidance of the competition of annual weeds which germinate in the spring. . Another is the avoidance of the risk of damage due to a dry summer spell while the crop is still in the seedling tender stage. While such special considerations may justify autumn sowing, generally the results from it are not as good as from November-December seeding. Whenever autumn sowing is adopted it should be carried out as early as possible, so as to admit of the» development of strong' plants before the dormant season of the plant commences.

Over wide areas good results are obtained by sowing the seed at the rate of 121 b. to 181 b. per acre through every coulter of a grain drill. By drilling half the seed in one direction and the other half across the other way any misses are avoided, and a very even stand usually results. The amount of seed used needs to be increased when the' tilth of the seed-bed is poor. . Drilling ensures the sowing of the seed to a more uniform depth than broadcasting; the latter, however, usually gives good results, and calls for the use of a slightly larger amount of seed. The seed should not be sown at a greater depth than lin., and if broadcast it may be covered by lightly harrowing it, a brush harrow being suitable for this purpose.

The merit of the Marlborough strain of lucerne has been established, and it may be generally recommended. Most striking claims are at times made in respect to other strains of lucerne, but conclusive evidence to substantiate such claims has not been submitted.

Inoculation

Many of the past complete or partial failures with lucerne are now known to have been due to absence from the soil of a particular micro-organism with which lucerne collaborates in an important manner essential to its thrifty development. There is no way which could be used in farm practice of discovering, before growing the

crop, whether the soil is inhabited by sufficient numbers of these microorganisms. Hence, although the organism is present in some soils in ample supply for the needs of the most successful lucerne, yet the safest course is to supply the organism artificially, this being termed inoculation. By carrying out inoculation one may at times supply the organism when it is already present in sufficient numbers to meet all needs, but one at least ensures its presence, and this is well worth while, as any other available course involves the risk of a failure attended by considerable outlay in seed,' manure, and cultivation. Supplies of the necessary organism are called “cultures,” and are obtainable from seed merchants, together with explicit instructions regarding the use of the culture. The charges, which must be prepaid, for cultures are as follows: For any quantity of seed up to 301 b., 2s 6d (minimum charge); for 301 b. to 601 b. of seed, ss; for 601 b. to 901 b. of seed, 7s 6d; for 901 b. to 1201 b. ,of seed, 10s; and so on. Treatment of seed with suitable cultures may subsequently be nullified if the seed is brought into contact with soluble fertilisers such as superphosphate, sulphate of . ammonia, nitrate of soda, kainit, and other potash salts. When treated seeds are mixed with any of .these fertilisers the inoculating organisms on the surface of the seeds are destroyed. However, excellent results have been obtained when inoculated seed has been sown with superphosphate and carbonate of lime mixed in equal proportions for about a week before the seed was brought into contact with the mixture. Evidence that the required organisms are present in adequate numbers is provided by the development of curious

growths known as nodules on the roots of the lucerne. Excellent nodule formation also occurs when seed sowing is effected by mixing inoculated seed with rock phosphate and basic slag. If desired, superphosphate can be used with safety, provided it is broadcast or drilled before seed, sowing. The cultures remain viable on seed for some days after treatment, but sowing immediately after treatment is recommended. Manuring On the basis of experience in many districts it has become the practice of successful growers of lucerne to apply 2 to 4cwt. of phosphate at or about the time of sowing the seed. Superphosphate, unless carefully used in the manner already described, may have a detrimental effect on the germination of the seed and on the inoculating, organisms. Hence, for safety, some favour the use at this stage of serpentine superphosphate, basic slag, or a mixture of equal parts of superphosphate and lime. In most districts it is very advisable to dress lucerne

at least annually with 2 to 3cwt. of superphosphate, which is at times successfully replaced by basic slag in the wetter climates. In some districts, such as in parts of Central Otago, there does not appear to be a profitable response to phosphatic manuring, but in other districts failure to apply phosphates has been a primary cause of past failures with lucerne. A number of successful North Island growers of lucerne advocate two phosphatic dressings annually, and the amount of mineral matter absorbed from the soil by a really productive crop supports such a practice, except in case of unusually fertile soils. Under conditions of relatively heavy rainfall, in which grass is prone to invade lucerne as a serious weed, phosphatic dressings should not be applied in the winter while the lucerne is still dormant. If applied at this stage the fertiliser would stimulate the grass and make it a stronger competitor of the lucerne —an effect the reverse of what is desirable. The manurial dressing may be applied with good results as soon as the lucerne has definitely made appreciable new season’s growth, or after the first cut of the season has been removed, if this occurs early, as is usually the case when the first cut is utilised for silage. When a second dressing in a season is practised it is usually applied after the second cut. In relatively dry districts —e.g., Canterbury— usual practice is to apply ■fertilisers during the winter months. Available evidence does not indicate any general need for the application of potassic or nitrogenous fertilisers to lucerne.

Treatment During First Year

The practice that should be adopted during the first year will vary greatly with circumstances. If annual weeds .such as fat-hen and thistles have developed rapidly, and threaten by their competition to weaken or even destroy the young seedlings, then it will probably be necessary to mow the •crop earlier than otherwise in order

to give the invading weeds a setback, but if weeds are not threatening to give trouble it is harmful to mow the young, plants until they are blooming or fresh young shoots have appeared at the base of the plants. The delaying of the first mowing until this- stage favours the growth of an extensive root system, whereas a relatively early first mowing diverts the energy of the plant to a renewal of the aerial portion, with -a resultant check to root development. In the warmer, districts lucerne sown in November will usually be at a suitable stage for a first mowing, in early February, and often a second cut will be available in April. In the cooler districts the first cut may not be obtainable until late - February or March, and unless the season is a favourable one a second cutting may not be advisable, although generally a second light cutting will be possible about the middle of April. The final cutting for the season should be carried out before the commencement of the dormant period of the crop; some growth on the plants during the winter is desirable, for it fosters the stronger development of the root system, and to

some degree competes with and checks the invading weeds.

Management At the end of its first winter a

lucerne stand may contain a heavy population of weeds; indeed, on this account the lucerne crop may seem to possess every promise of a failure. The next few months probably constitute the most critical period in the life of the crop. . However, provided the lucerne plants are present in satisfactory numbers and have been able during the previous months to develop strong root systems, there is no essential reason why with suitable management a weedy crop should not become a success. When the new growth coming from the crowns is approximately 2in. high, which frequently will be the case about September, the vegetation that has been standing during the winter may be removed by mowing, which should be adjusted so as to leave 3 to 4in. of stubble. Mow-

ing in this manner may with benefit be made an annual practice, and if mowing is not carried out at this stage then at times light grazing is advantageous, but a field should not be grazed in its first year. Further, the heavier the soil .the less likelihood is there of benefit from such grazing. At this stage topdressing could suitably be carried out. Generally the new growth, which should be allowed to grow unchecked, provides a cut towards the latter part of November. It is likely that year " after year this first cut will contain a substantial proportion of weeds, inclusive of plants which ordinarily are . useful, but . which when invading lucerne are weeds. Partly because of its weed content and partly because the weather usually prevailing at this period is unfavourable to haymaking, the first cut of lucerne is as a rule most advantageously used for silage. Further, because of the weeds in the first cut it should be made, early enough to avoid ripening of the weed seeds.

If lucerne is mown in November, as suggested, it ordinarily should again be - at a stage suitable , for mowing early in January. The time and number of subsequent cuts will be determined principally by the rate of growth of the crop, but at least two other matters should be taken into consideration: In the first place, the crop should not be mown so late in the season that some fresh growth will not develop from the stubble, since it is against the welfare of the crop for it to pass the winter in the bare

stubble state. In the second place, mowing should be done only at a particular. stage of development of the herbage. This stage is reached when new shoots are just starting from the crowns or bases of a considerable number of the plants. Usually when fresh shoots have so developed about a quarter of the plants will be in the early flowering condition, but as this does not always occur reliable guidance as to the time to cut is not provided by observation of the flower development. If the herbage is cut too late feed of unnecessarily low nutritive value is obtained—it is unduly fibrous, and the proportion of leafage as distinct from

stems is small. This is of importance.,, as the leaves are the most nourishing" portion of the crop. Further, if it becomes the rule to mow the crop at a later stage than that previously advocated, then the number of cuts obtainable each year will very likely be reduced with consequent loss in total annual production. Unduly delayed mowing of the first cut of the season is a fairly common fault when it is not utilised for silage. It is a fault which is very likely to lead to serious injury to a crop which is fairly heavily infested with weeds which started growth earlier in the season than did the lucerne, and which by this earlier

development . have an advantage over the lucerne in the vitally important competition for direct sunlight. The longer the first cut is delayed, the longer are such weeds depriving the lucerne of direct sunlight and thereby weakening it.

Mowing before the crop is mature enough is not such a common fault as mowing when it is too mature, but is prone to occur when a farmer is specially seeking succulent leafy forage in the summer, or when an endeavour is made to secure at the end of the growing season an additional cut, even though it is only a light one and possibly should not be harvested. Cutting lucerne at an immature stage provides highly nutritious herbage, but, if persisted in, rapidly leads to a weakened stand of decreased production. This results from the fact that the root system is drawn upon for the production of leaves and stems immediately after each cutting, and the more frequently this occurs the more heavily is root development reduced. To cut an immature growth at the close of the growing season is likely to be particularly injurious, because it results in a weakened stand to carry through the winter and compete with weeds in the spring.

Cultivation

Principally as a means of ■ reducing the competition of weeds, cultivation of lucerne is at times well worth while. For' such cultivation to be of value it is essential first that the lucerne be not greatly damaged, and second that the cultivation be done under the conditions which will most greatly reduce the competition of weeds. In view of these requirements it follows that the implement employed should be fitted with tines designed for lucerne cultivation, that . the use of disc harrows is generally too. severe, and that dry summer or autumn conditions should be chosen for the work. As a rule a suitable time for such cultivation is after the second or third cuts;

the dry weather which then is commonly experienced assists in the destruction of the weeds. Cultivation of lucerne has proved of value, most commonly on open porous soils on which weeds may be disturbed effectively without : at the same time materially injuring the deep-rooting lucerne. It is certain, particularly on the heavier types of soils, that cultivation has at times resulted in more harm than good, because it has led to a 'gradual thinning-out of the lucerne plants until eventually they become so sparse as to make the area unprofitable.

A method that is proving a useful modification of simple cultivation of lucerne which is being invaded by weeds is practised widely in parts of the North Island. This consists in sowing in late April or early May from | to 1 bushel of Algerian oats on stands which have been well cultivated shortly after having been mown or grazed. The cultivation injures the weeds and provides a seed-bed for the

oats, with which about 2cwt. of superphosphate to the acre is usually applied. The oats furnish good feed in the spring, if required, and subsequently there will be available a heavy cutting of a mixture of oats and lucerne. It is as a rule highly advisable to use for silage the material thus provided. ? If it is not mown at. an early stage the oats by shading the lucerne will unduly weaken it and thereby more than counterbalance the good they have done by checking persistent weeds. The success of the practice •of growing oats with lucerne in this manner will depend to some extent on the texture of the soil; the practice is followed almost wholly on friable soils.

Cultivation under relatively wet or cold conditions is an unsound practice; it merely injures some of the lucerne plants without leading to a useful reduction of the weed competition. . Suitable cultivation can be carried out by use of , the tine harrows or of a light spring-tooth cultivator possessing specially narrow teeth.

If stem-rot (Sclerotinia trifoliorum) has appeared in a stand of lucerne, cultivation is most inadvisable, as it assists in the spread of this disease by tending to scatter infected soil. In order to enable crops infected with stem-rot to survive in a useful condition as long as possible the aid to weed suppression provided by cultivation must be replaced by specially good management in respect to such matters as time of mowing and adequate manuring.

Irrigated Lucerne

The following statement relative to lucerne under irrigation is an extract from Department of Agriculture Bulletin No. 120, “Irrigation Practice

for Central Otago Conditions,by R. B. Tennent and J. R. Marks: — “Under irrigation frequent cultivation of lucerne is a great necessity. One of the commonest causes of a lucerne stand rapidly going out is the intrusion of weed plants. Of these probably the grasses are most aggressive, and it is only by repeated cultivation that their invasion can be arrested. By cultivating during the winter months at least twice with a strong spring-tooth cultivator the bulk of the weeds can be kept under control. Where it is possible a cultivation after each cutting is desirable. Not only will cultivation of this description check the growth of weeds, but its secondary effect of breaking up the consolidated soil, thus separating it and lessening the rate of evaporation, will' be of great advantage in maintaining the vitality of the crop. Any damage likely to accrue from this practice may be considered as negligible' in contrast with the benefits conferred on the crop.” Unfortunately, even with a maximum amount of cultivation, couchgrass (.Poa pratensis) gradually asserts itself, until in the course of from five to eight years the lucerne stand becomes a mixture of probably 50 per cent, grass and 50 per cent, lucerne. .Experience has shown that it is practically impossible to renovate a stand of this mixture without ploughing and resowing, and probably the most practical method of dealing with a field in this condition is simply to treat it

as a grazing paddock and establish fresh, lucerne elsewhere. Grazing To secure for lucerne a long life of maximum production grazing of the crop should as a rule be avoided. The consolidation caused by grazing favours grass, and thereby increases the competition with the lucerne. But at times despite this it is not practicable; or desirable that the farmer should abstain totally from grazing of the stand. Provided the conditions are favourable to lucerne, grazing, if carried out carefully, may not do much

harm to established stands, but grazing of lucerne in its first year is not advisable. Close and continuous grazing of a lucerne crop may be expected to lead to a permanent reduction in the yield from it. On the other -hand, successful lucerne fields have been grazed first in the spring to remove coarse growth present from the winter, and second in the autumn when an intermediate amount of growth not worth mowing is available. Particularly is close grazing of lucerne during its dormant winter period productive of harm, as also .is grazing when the land is so wet that it is subject to poaching by stock. Grazing at times has the effect of introducing viable weed seeds in the dung of animals fed on herbage which has been allowed to ripen seed, and because of this, and apart altogether from its direct harmful influence on the lucerne plants and on the soil, it may shorten the profitable life of a stand.

Grazing of green lucerne by dairy cows calls for care in order to avoid hoven or bloat in the animals. ' The lucerne should be fed sparingly at the beginning, and not when it is wet. To avoid the danger of the stock eating it greedily they should not be grazed on lucerne until they have had an opportunity of partly satisfying their appetites on other feed. Hence, as a rule they should not be given access to the lucerne until late in the day, and then only for half an hour or even less in the early stages; and when the stock are in the lucerne they should be watched carefully for signs of hoveri. Gradually as the stock become accustomed to such feeding the period may be extended from half an hour to an hour and a half, and at the same* time the danger from bloat will lessen,, although . there is always danger if hungry animals are given access to green lucerne. / Field experience shows that the danger of bloat is greatest when succulent, immature lucerne is concerned.

As a rule the care necessary with dry stock in grazing lucerne is not as great as that called for with dairy cows, but particularly during the first few days the danger should not be overlooked, and precautions should then be taken to avoid such causative conditions as empty stomachs and wet lucerne. Grazing of lucerne has been carried out satisfactorily not only with cattle but also with sheep and pigs; these call for greater care than cattle in order to avoid injury of the plants. When a weed is viewed as a plant in a place where it is not desired many highly-productive plants, such as ryegrass, cocksfoot, and clovers, may be weeds when considered in relation to lucerne. If a lucerne field has become badly invaded by plants which provide useful feed, or if much cultivation is needed to prevent the invasion of lucerne by large numbers of such plants, then it may be sound practice to utilise the lucerne area chiefly as a grazing field from which probably it would be possible to obtain not more than three cuts in the year, in the first of which lucerne would be a minor constituent. The relatively small amount of mown material obtained from such a practice would be balanced by the increased grazing secured and the absence of any need for cultivation. If thinning-out of a lucerne stand due to such a cause as repeated or excessively severe cultivation has occurred to such an extent as to make the stand of doubtful value, it is at times well worth while to , cultivate it in April sufficiently to provide a seedbed, and on this bed to sow Italian ryegrass or prairie grass. By this practice the field may be made highly productive for another year or two'. Mowing Lucerne Lucerne is of outstanding value when utilised by mowing. Indeed, the highest production may be expected from lucerne when it is treated essentially as a hay, silage, or green crop to be mown and carted out to stock. Used

as a mown crop it is fitted to serve as an exceedingly valuable companion crop to pastures, in that it may readily

be made to supplement their feed in those seasons in which pasture growth is scant.

The first cut of lucerne, which usually should' be made in November, is as a rule most conveniently and effectively utilised in silage. This is partly because in localities where mild weather favours the growth of grasses and weeds in early spring, it is generally so mixed with other herbage as to provide material well suited for silage production, and partly because the weather usually prevailing when the first cut is made is very unfavourable to the production of good hay. The amount of green material available from the lucerne area may not be sufficient for economical silage. Then, to provide the required bulk, material from the pastures may usually be saved with that from the lucerne area or the lucerne may be saved with such a crop as green oats. •

Apart from the first cut of the season lucerne may be used either in a green condition as a summer supplementary

crop to grass or as a hay crop. When it is being fed as a green crop care must be taken to use it before it has reached a woody or stemmy condition. This is particularly advisable in the feeding of dairy cows. As a means of supplementing the feed from pastures green lucerne has given excellent results when fed together with soft turnips. Calves, pigs, horses, and sheep have all fared well on green lucerne.

The making of good lucerne hay calls for care designed to avoid the loss of leaves which readily occurs if handling is faulty. The mown crop should not be left in the swathe to dry sufficiently to allow of carting in. If this were done the leaves, which are much more nutritious than the stalks, would become dry and brittle, and would fall off readily before enough sap had been removed from the stems to allow the herbage to be stacked. Because of this, cocking should be practised in saving lucerne hay. Lucerne hay is at times stacked before it is dry enough. This probably arises because the stems do not become dry enough as quickly as the leaves. Hence in the making of lucerne hay the condition of the stems should receive special attention.

Well-made lucerne hay is particularly nutritious, its content of protein and mineral matter as a rule being notably high. On this account lucerne hay is of special value for feeding to cows in milk in the winter or spring, if fresh leafy grass is then scarce. Lucerne hay is also fed to horses with excellent results.

Diseases of Lucerne Although several fungoid diseases

have been found attacking lucerne in New Zealand, none of them, with the exception of stem-rot, is of great practical moment. The following are the most common ones: —

(1) Stem Rot. The fungus Sclerotinia trifoliorum (which is synonymous with Rhizoctonia) is a serious disease of lucerne in this country and can

easily be seen if plants which have been attacked recently are examined during a spell of wet, warm weather. Then a whitish, soft, cobwebby growth will be found attached to the infected plants. The following statement prepared by the Mycological Laboratory relates to stem-rot:—

“The disease becomes readily noticeable on account of the rapid manner in which it induces wilt, followed by death, of attacked plants. Examination of such plants shows that ■ the stems near the crown are infected, these carrying discoloured lesions, which are commonly concealed by a weft of coloured mycelium. Embedded in this mycelium may often be found sclerotia of the fungus, for the species differs from Sclerotinia sclerotiorum in producing these bodies externally, whereas in the latter they are invariably produced within the cavity of the stem. Field experience has tended to show that this disease is carried with the seed, and this evidence has been strengthened by recent laboratory investigations. Consequently, it is advisable to have seed tested for the presence of the disease, and to recommend that only lines found to be free should be sown in new stands. Where the disease has become established in an old stand, it may be held in check by the following treatment: —

“(a) Remove infected plants and those showing signs of wilt, as it is by means of sclerotia produced on these that the disease is able to persist.

“(b) Lime the soil at the rate of 1| lb. per square yard with freshlyprepared hydrated lime. Soil fungi of this type are intolerant of alkaline conditions, and can be held in check by lime dressings, provided the lime is of the type specified, since experience has demonstrated that carbonate is practically worthless.”

If possible, a lucerne area infected with stem-rot should receive no cultivation which tends to spread the infection. Moist conditions favour the disease. Hence drainage of wet patches in a field should receive attention, and

diseased areas of the crop should be mown to enable the stems of the plants to be as dry as possible. Grazing of fields infected by the disease tends to spread the disease to healthy portions of the crop. (2) Leaf-spot, due to Pseudopexiza ■ medicaginis, is characterised by small dark-brown or black spots on the surfaces of the leaves. The disease is common on lucerne especially in stands which are suffering from drought, from poor drainage, or from competition of weeds. In fact, any unfavourable condition will induce attack. The 'spots are accompanied by yellowing of the leaves, and in severe cases yellowing is followed by the fall of the leaves. Improvement of crop conditions where these are inferior will tend to reduce the disease. Generally a troublesome attack of the disease may be checked by mowing the crop. (3) False Mildew, due to Peronspora trifolii, results in the development of a downy yellowish-grey or purplish

mould on the undersides of leaves. Infected plants are usually' stunted, and they are generally found on wet, low-lying portions of a field. To control the disease it is necessary to bring about dry conditions of both ground and crop. Hence wet areas should be drained and infected patches should be mown close to the surface. i Summary (1) The area of lucerne in New land is relatively small' and is increasing but slowly. (2) Experience in New Zealand and overseas has’ indicated definitely that lucerne is not specially exacting in its requirements, and indeed that it may be grown with success over a wide range of soil and climate. Drainage and fertility are important factors in success with lucerne. (3) A successful lucerne field is of remarkable value because lucerne is characterised by high yield, high nutritive value, reliability during crucial dry periods, low cost of production, and a capacity to increase rather than to exhaust the soil content of nitrogen. (4) During the period of its establishment lucerne is unable to compete successfully with many common weeds; hence for the sowing of lucerne clean ground should be selected. (5) A fine, firm seed-bed, which is highly desirable, calls for early and ample preparatory cultivation. (6) Usually liming of lucerne areas is highly profitable. A dressing of 1 ton per acre -of ground limestone at the time of the establishment of the crop is the general practice of successful growers of lucerne, and. the initial dressing is supplemented by subsequent and usually smaller dressings at regular intervals.

(7) Sowing of the seed usually is not 'advisable until late in November or early in December, when warmer conditions obtain. Under special circumstances autumn sowing is at times justified. From 12 to ■ 181 b. of seed per acre, drilled in rows 7in. apart or broadcast, gives good results. Marlborough seed may be recommended for general use. (8) Inoculation of the lucerne stand is often essential, and as a safety measure should be carried out generally. (9) Topdressing of lucerne with phosphatic fertilisers is very advisable, and at times governs the failure or success of a crop. (10) In its first year lucerne should not be grazed, and unless weeds are shading it excessively it should not be mown until young shoots have appeared at the crowns or bases of the plants. (11) Care should be taken to mow established lucerne at the correct time. The first cut of the season should be removed early, usually in November, and subsequent cuts when fresh shoots at the crowns of the old plants have developed a length of lin. to 2in. (12) Particularly when a lucerne stand is being invaded by other plants, surface cultivation of the lucerne may be-of considerable value, provided it is done at a suitable time and in a suitable manner. ,It at times proves advantageous to grow antumn-sown oats in lucerne as a means of suppressing more persistent foreign growth. When this is done the first cut of the season should be removed at an early stage. Excessive or drastic cultivation may thin out a lucerne stand to an undesirable extent. Cultivation may also spread stem-rot.

(13) Grazing of lucerne is not to be generally recommended, and when practised special precautions are necessary. • (14) As a mown, crop lucerne is of very great value. The first cut of the season should generally be • saved as silage. Usually other cuts should be saved as hay or fed in summer in a green condition. (15) Lucerne is attacked by several fungoid diseases, but only stem-rot is of considerable moment. The ravages of stem-rot may be reduced by suitable management. Conclusion Lucerne has outstanding merits, and deserves a much more important place than it holds in our livestock farming. It has had a place in New Zealand farming for many years, but the area devoted to it is small and is expanding but slowly. This will probably continue to be the case until the true facts regarding lucerne are more generally known. Lucerne is not an expensive crop; it is not a difficult crop; it is not an exacting crop; it is not an exceptional crop to be grown with success only under very particular circumstances on a limited range of soils.

MAKING THE MOST OF SILAGE r I 4 O ensure that stock get the best out of silage it should be fed as fresh from the stack as possible and not allowed to deteriorate by lying out in the paddock for a lengthy period prior to the stock having access to it. Once silage is exposed to the air it dries out and spoils fairly rapidly, and the feeding value and palatability are reduced.

In opening a stack of silage for feeding out there are two methods that can be employed. J First, the whole of the stack can be uncovered by removing the soil, and the whole face fed from day by day, or, second, a section can be uncovered and fed right to the ground before a second section is uncovered. Both , methods have their supporters and their critics. Either method can, be right, depending upon the relative size of the silage stack and the herd. With a small to medium size stack and a large herd it is all right to uncover the whole surface and feed it right down, but where the herd is small and the stack large only a section should be fed out before a second one is opened. The amount of silage that should be removed each day should not be less than 4 to 6in. in depth, for if only an inch or two is removed, the stock are getting a driedout, inferior fodder.

» Acres. 1927-28 Acres. 29,257 1928-29 30,808 1929-30 31,690 1930-31 32,561 1931-32 34,867 1932-33 35,370 1933-34 : 37,350 1934-35 39,087 1935-36 40,857 1936-37 38,802 1937-38 38,691 1938-39 37,023 1939-40 39,614 1940-41 41,665 1941-42 42,211 1942-43 42,842

Mares .. 340 days i from date of service date of service Cows . , . 283 ” 99 99 »» Ewes .. . 150 ” 99 99 99 99 99 Sows ., . 116 ” 99 99 99 99 Bitches . 63 ” 99 99 99 99 Rabbits 28-30 ” 99 99 28-30 ” 99 99 99 99

Gestation Table