Forage Cropping in Matamata County

New Zealand Journal of Agriculture, Volume 98, Issue 4, 15 April 1959, Page 347

Forage Cropping in Matamata County

By

B. A. GUNNING,

Instructor in Agriculture, Department of Agriculture, Matamata

THOUGH forage cropping is undertaken principally as an adjunct to pasture renewal, to cash in on the period under the plough, it can play an important part in filling in gaps in pasture production. In Matamata County two main periods of inadequate pasture growth occur—in the dry months of January to March and in winter. By raising carrying capacity in these crucial periods forage crops can raise production for the whole season. MATAMATA County is an intensively farmed district. The 260,000 acres farmed are about equally divided between dairying and fat lamb raising. About 8,000 acres are cropped each year, almost all being in forage crops for cattle and sheep.

There are two main soil and climatic zones in the county. North of Putaruru the soils are all free-draining yellowbrown sandy loams of volcanic origin. This zone has a long farming history, and soil fertility has been raised to a point where pastures of ryegrass and white clover thrive with only a small proportion of other constituents.

South of Putaruru and on the Kaimai Hills and the upland Mamaku Plateau these soils have been overlain by the much more recent pumice soils from volcanic material of low natural fertility. Though these soils respond well to phosphatic and potassic manures, development of the region into a prosperous farming area was delayed 50 years, pending the discovery of cobalt as the solution to bush sickness. A lesser build-up of soil fertility here means that only some ryegrass is found in the pastures, which at certain seasons are notably clover dominant. From Putaruru (530 ft.) there is a rise of altitude to Tokoroa (1,100 ft.) and a marked deterioration of the winter climate is noted as one moves south. Cooler temperatures and poorer pastures cause spring growth to begin at Tokoroa a month later than at Matamata. Many dairy farmers at the southern tip of the county feed out for nearly 6 months over the colder months. The saving of autumn pasture for winter and spring use is not the complete answer to the winter problem of this area. Saved pastures of cocksfoot and clovers tend to frost burn, and though Yorkshire fog supplies much useful feed, it soon becomes unpalatable and deteriorates as a milking feed for dairy cattle and ewes. To compensate for the long winters, however, there is generally satisfactory growth from pastures during summer in this south zone. The three factors responsible for this condition are the better summer rainfall than in the north zone, the water-retentive, vesicular nature of the pumice soil, and the suitability of soil and climate to the growth of such summer growing species as cocksfoot and red and white clovers. In the north zone the position is reversed. Perennial ryegrass-dominant pastures, usually with a high proportion of short-rotation ryegrass, and often with a considerable amount of prairie grass, provide excellent winter

feed. An extension of the practice of saving autumn pasture to as much as three-quarters of the farm area on dairy farms, and large proportions also on sheep farms, has meant that the supplying of winter feed has been relatively easy in this zone of mild winter climate. Owing to the ability to grow winter feed the carrying capacity of many dairy farms in the Matapaata region has been raised to almost a milking beast per acre, with all herd replacements also carried on the farm. . As carrying capacity has risen the summer feed position has become more difficult. Place of Forage Crops Forage crops are capable of relatively high yields in a short growing period. White-fleshed turnips, for instance, are the lowest yielding of the crops commonly grown in Matamata County. Even so, an acre of turnips yielding 30 tons will produce sufficient feed for 10 dairy cows for 6 weeks, supplying all the animals’ maintenance requirements and their requirements for the production of J lb. of butterfat per day. To maintain production of 1 lb. of butterfat per day this ration would need to be supplemented by a limited amount of pasture, or pasture and silage. Approximately threequarters of the animals’ feed, however, is derived from the crop, so that over the 6 weeks total production from the crop can be reckoned as three-quarters of 420 lb. of butterfat (10 cows at 1 lb. per day for 42 days), or 315 lb. of butterfat per acre. In growing the crop the paddock is out of grass for about 6 months. The yields from most of the other commonly grown crops compare favourably with that of turnips. The average per acre yields and dry matter contents of some commonly grown summer forage crops are: Yield Dry matter Crop per acre percentage tons Turnips .. 25-30 8 Chou moellier 30-40 12 Maize .. .. 40-50 15 It is easily seen, therefore, that theoretically the high yield of forage crops should make them a sound proposition for raising farm production. Unfortunately, however, the matter is more complicated than appears at first sight. Three main factors detract from the profitability of forage cropping in Matamata County: 1. Regrassing the cropped paddock is costly and is in fact the greatest single cost of the cropping programme. In addition to the outlay for grass seed and cultivation there is the cost of extra manure on the young pasture,

which in Matamata County, if a firstclass pasture is to be obtained, must amount to almost a ton of superphosphate per acre over the first 18 months. When an old run-out pasture is cropped all the regrassing cost can be attributed to pasture maintenance, for in any case such a pasture must be ploughed and regrassed, and here the crop is “free”. When a good pasture is ploughed for a crop, however, the cost of regrassing is part of the cost of growing the crop. More important, when a good pasture is ploughed it is possible that the new pasture established after the crop will be inferior to the original, and the lower production from the new pasture can more than counterbalance the value of the crop. There are few farms, ' however, with no pastures warranting renewal. 2. Farmers are generally unwilling to cash in on the extra feed provided by the crop by putting on extra stock to utilise it. There is consequently a tendency for pastures to grow rank and unproductive over summer or winter when the crop is -being fed. This means that the crop merely substitutes for pasture, and there is no net gain in production. 3. Unwillingness to stock up certainly stems largely from the general unreliability of forage crops in Matamata County. Soil fertility generally is high enough to grow any crop, but weeds, pests, and diseases are such a hazard that crop failures and half successes are almost as common as successes.

However, with correct choice of the crop to be grown and proper weed and insect control most of these hazards can be overcome. • In the author’s opinion the county’s general need for pasture renewal warrants far more forage cropping than is at present being done. It is hoped to show how forage crops may be reliably produced, so that extra stock may safely be carried to cash in on the extra feed grown. Requirements Dairy farmers in the zone north of Putaruru require a crop that will keep cattle milking over January and February and part of March. Silage certainly helps maintain production over this period, but the amount of silage that can be conserved in November is insufficient to carry' all the burden for the whole of the 2 to 3 months’ drought period, unless stock numbers are sacrificed. A winter crop is not required. A few years ago it was common for a paddock to be ploughed in November for a crop of swedes to be sown in December and fed in June and July, after which the paddock was sown to white-fleshed turnips or chou moellier for summer feeding. With regrassing in autumn two crops could conveniently be squeezed into an 18-month period. This practice is relatively uncommon now for two main reasons: First, the winter crop is not now generally required, and secondly, the growing of a winter crop means that

weeds such as redroot (Amaranthus retroflexus') and willow weed (Polygonum persicaria) grow and seed in the crop. . The growth of weed seedlings in the following spring makes the growing of a second crop difficult, and it should be remembered that it is the summer crop which is important. Indeed the two weeds named have become so troublesome that it is now difficult on many properties to grow even a first crop of turnips. The more pasture renewal that is done, and the higher the soil fertility is, the more troublesome do these .weeds become. There are, indeed, pre-emergence weed control measures, . which will be described later, but these measures are difficult and depend on obtaining the right weather at the time of sowing. White-fleshed turnips are the crop most easily smothered by these weeds, and where these are troublesome a change could well be made to a crop better able to cope with competition. Chou moellier is the first obvious choice, but even this crop often succumbs to competition from vigorous weeds like redroot. Maize, however, is very rarely defeated by weeds, and even if there is a chance of this, there are relatively foolproof post-emergence methods of weed control applicable to maize crops. Maize also does extremely well under the high fertility conditions where weeds are most troublesome. Further, since maize is a heavy yielder, smaller areas need to be grown, a condition which well suits the farm where a fair amount of pasture renewal has already been done. Yet a further advantage is that maize is sown at the end of October, a month later than turnips or chou moellier. This means that there is still plenty of time to sow maize after it has become obvious that a previously sown crop of turnips or chou moellier has failed. For the sheep farmer in the north zone the requirements are more complicated. First and foremost, a crop is required on which ewes may safely be flushed and tail-end lambs fattened in a facial eczema outbreak. Secondly, a crop is helpful (though not essential) for wintering cattle and carrying hoggets safely through autumn. Unfortunately, the eczema period extends beyond the time when resowing of pasture is successfully done. At present most sheep farmers compromise by taking their chances with eczema and providing a winter crop only in occasional seasons. It is felt that a cropping rotation of as little as 3 per cent of the farm area would provide relative immunity from facial eczema for ewes and lambs, minimise hogget losses, and help winter cattle as well as provide for pasture renewal. Eczema-safe feed must be a leafy crop able to smother- out all traces of ryegrass, and lamb-fattening food must be palatable.

The weeds which make cropping difficult on dairy farms are not generally as troublesome on sheep farms. A suggested rotation actually now used by a few farmers is as follows: . A paddock is ploughed each September and sown to thousand-headed kale or chou moellier. This is used for flushing ewes during an outbreak of facial eczema, but if not required then, it can be kept for wintering cattle and hoggets. If chou moellier is chosen, it can be used also to help fatten lambs, whereas thousand-headed kale, being relatively unpalatable, is not suited to this. Facial eczema, however, may make it necessary to feed the crop heavily to ewes in autumn, in which case there would be better winter recovery . from thousand-headed kale, which is consequently thought the better crop. The crop is cleaned up by cattle in June and July, and the. paddock sown to a catch crop in September, which is fed before regrassing in March. The catch crop should provide - the lambfattening food, and it may be chou moellier. If the above routine were adopted, each paddock ploughed would be out of grass about 18 months and provide two crops— winter and a summer one—sharing the cost of pasture . renewal. Two paddocks would thus be under the plough each summer, one producing its first crop for autumn and winter feeding and the other its second for summer fattening feed. In the south zone, it will be remembered, summers are relatively favourable, but winters are long. Dairy farmers here need a crop to help them through winter, and the growing of such a crop is indeed almost universal. Swedes and chou moellier are admirably suitable. The problem of weed competition with the growing crop is of little consequence here, where crops are in fact .easily grown. Swedes in. particular yield much more heavily than elsewhere in the county. In this region of cooler and moister summers pastures can be sown in spring following the winter crop of swedes or chou moellier. Most farmers agree, however, that though spring sowings of pasture are reasonably successful, autumn sowings are usually a little better. They also believe that though a summer crop is not essential, it is still a help and is worth while for the slight extra expense. Turnips are the usual choice for the summer crop, with chou moellier a fairly close second. As an alternative to the above rotation some farmers in autumn sow oats or ryecorn, which is grazed in winter and then allowed to recover for spring and summer use before ploughing and

resowing pasture in autumn. The lower cost of such a system is offset by the lower yields. The requirements of sheep farmers in the south zone are much the same as those of the north zone. Eczemasafe feed and winter feed are necessary. Requirements differ, however, in that the feed deficiency in winter is much greater. Most sheep farmers here winter cattle on swedes, but there is little attempt to provide crops for the period of facial eczema danger. The rotation suggested for sheep farms in the north zone could advantageously be applied here. However, larger areas would need to be cropped than in the north because of the severe winters. Chou moellier could be used in preference to thousand-headed kale, for, as large areas are sown, autumn feeding would be light and recovery better. Alternatively, the suggested rotation could be applied on a small scale, with the growing of a swede crop exclusively for winter use. In this region pastures can be resown quite successfully in spring if a summer catch crop is not desired. Individual Crops The crop species mentioned are the only ones which are extensively used in Matamata County. Some . species which are a feature of other districts are seldom if ever seen here. Rape is never grown in the Matamata district, because it cannot be relied on to ripen under the humid conditions. Lupins are low yielding by local standards and very prone to fail because of stem rot diseases. Millet is grown to a very limited extent on dairy farms where a quick catch crop is required, but the yield is disappointing in an area where soil fertility will grow better crops. Carrots, mangels, fodder beet, and sugar beet are never grown as forage crops for cattle or sheep, though they are occasionally grown for wintering pigs. The labour required for growing these crops on a large scale is not available. Green-feed Crops Green-feed crops of oats and ryecorn have been mentioned briefly above. These crops are used to some extent at the south end of the district, in place of swedes, but their main use is for sowing in areas where resowing of pasture has been delayed beyond the end of April. Turnips White-fleshed turnips are the most favoured crop for all purposes. Apart from susceptibility to weed invasion, turnips are easily and cheaply grown and easily fed. Cows milk well on them and there is little waste when they are fed off. As well as being used for summer feed turnips are often established as late as the end of March

to provide winter feed. Yields of over 30 tons per acre have been recorded from turnip crops sown at the begin-, ning of March. They are a useful crop to establish where previously sown swede crops have failed, and the practice of sowing them in autumn is increasing. Indeed, some farmers who have had difficulty in getting swede crops established in December because of weed competition plough in January or February and sow turnips in March, when germination of redroot seed is not aggressive. The varieties Green Globe, Red Globe, and Purple Globe have all been extensively used in Matamata County, the normal practice being to sow a portion of each field in Green Globe and another portion in one of the other two varieties for early feeding. Recently, however, York Globe has increased in popularity, not only as a hardy, quickgrowing, good-lasting autumn-sown turnip, but also for spring sowing. It seems probable that York Globe will eventually replace the other varieties in the county. Chou Moellier Where soil fertility is reasonably high chou moellier is a heavieryielding crop than turnips, and it competes with troublesome weeds a little better than turnips. However, the cost of chou moellier seed, the difficulty of feeding the crop off, and the waste of large proportions of it in feeding make it less popular than turnips for summer feed. As a winter crop chou moellier is a close second to swedes. In Matamata County, however, chou moellier must be grazed before the beginning of August, as experience has shown that grazing during this month is liable to precipitate an outbreak of red-water disease in the stock. Giant chou moellier is usually chosen for cattle and the medium-stemmed variety for sheep. Thousand-headed Kale Thousand-headed kale is not a popular crop partly because its yield is poorer than that of chou moellier and partly because it is unpalatable. Where winter recovery of an autumn-grazed crop is desired, however, thousandheaded kale is superior to chou moellier. The latter appears also to be more susceptible to soft-rot disease after damage during autumn grazing. Maize The practice of growing maize for summer dairy cattle food is growing year by year, and the suitability of maize for this purpose has already been referred to. There appears to be little to choose between the various maize varieties. Swedes The swede varieties Superlative, Grand Master; and Crimson King considerably outyield all other varieties in Matamata County. As Superlative,

the quickest-maturing variety, appears to go off quicker than the other two, its use is decreasing. Seedbed Preparation and Sowing of Seed The plough, discs, and harrows are the main implements of seedbed preparation, though some farmers use rotary hoes or giant discs. It is unusual for pasture to be broken up for a summer crop before the middle of September, because pasture growth rate does not usually catch up to the requirements of the dairy herd until this date and few farmers are willing to sacrifice a paddock until feed becomes plentiful. As turnip or chou moellier crops need to be sown before mid October for best results, there is little time for seedbed preparation for these crops. For winter crops of chou moellier, normally sown in November, or for maize crops sown late in October or early in November the position is not so acute. Swede crops, however, are sown at the end of December, and since many of these are sown on paddocks from which silage has been harvested in late November, there is again little time for weathering of the seedbed.

There are few drills in the district, and it is consequently, more usual for the seed to be broadcast mixed with the manure through the topdresser. Brassica seed is usually covered by brush harrows and maize seed is usually disced in. Rollers are also very scarce, and broadcasting seed on a rolled surface is uncommon. The manure sown with the seed of brassica crops usually consists of 3 to 4 cwt. per acre of serpentine superphosphate. Potassic or nitrogenous fertilisers are seldom used on crops, and indeed limited experimental work in the Matamata district on the use of these manures on brassica crops appears to indicate that they are not warranted except perhaps when exceedingly poolpastures are ploughed to grow the crop. Maize crops are usually sown with 3 to 4 cwt. of superphosphate and some blood and bone manure, usually 1 to 2 cwt. Maize is sown at 100 to 120 lb. of seed per acre, and turnips and swedes at 14 to 16 oz. Most chou moellier and thousandheaded kale crops are sown at 2 lb. of seed per acre, but for some chou moellier crops up to 5 lb. of seed is sown to produce a leafy feed for dairy cattle.

Utilisation The method adopted for the feeding of the crop to stock varies somewhat with circumstances. Generally, utilisation is good on dairy farms but rather poor on sheep farms. For dairy cows the electric fence is usually used to feed the crop. With turnips usually one break is fed daily, but in some cases two breaks are fed daily, namely, after milking night and morning. With this crop it is necessary only to erect the fence, but when maize or chou moellier is fed it is necessary to cut a swath through the crop . with the mower each time the fence is re-erected. A new break is then allowed only every second or third day. Sometimes, however, the mower is used each day to cut the day’s ration of crop. The electric fence is then erected on the edge of the mown area to prevent stock wandering into the standing crop. This method greatly reduces the waste which occurs when a standing crop is fed. Care must be taken to erect the fence so that the cows are unable to reach over it and short circuit it by pulling standing stalks on to the wire. Some farmers use fingerwheel side-delivery . rakes to move heavy chou moellier or maize crops clear of the standing plants. Few farmers now harvest a crop by hand for feeding to stock. A measurement was made near Matamata of the amount of waste occurring when a crop of turnips was fed to dairy cows by daily breaks with the electric fence. The loss of about 12 per cent of the crop by weight left by the animals is not very great. There was very little leaf left, most of the waste consisting of small bulbs or deeply embedded ones. Small bulbs constituted 40 per cent of the waste, and probably these would not be pulled if the crop were hand fed. Waste could be reduced if the field were disced after grazing to lift embedded bulbs, which would then be readily eaten. Therefore the labour required for hand feeding of turnip crops, and of maize and chou moellier crops fed out under dry conditions, appears to be unwarranted, as these may be efficiently fed by the mowing and electric fence method. Winter crops of swedes or chou moellier are more normally fed on dairy farms by using the electric fence for breaks designed to last about 3 days when the herd is allowed access to the crop for a specified period each day. On sheep farms usually the crops are divided into two or, at the most, three breaks by temporary wire-netting fences. Under these conditions there is much waste of the feed from trampling of leaves into the soil. It is also not uncommon for a crop lightly grazed by this method to go off very quickly owing to soft-rot disease, which quickly attacks damaged tissue in a mild wet season. More attention

to methods of utilisation would enable sheep farmers to grow a smaller area of crop with the same results as from a large area badly utilised.

Weeds Controlled in Forage Crops SINCE this article was prepared, the sodium salt of monochloroacetate ("Monoxone" and "Stantox MCA") has been used effectively to control some weeds in chou moellier and swedes and should now be used in preference to TCA. "Monoxone" and "Stantox MCA" at up to 15 lb per acre, preferably when the weeds are small and the crop has three or more leaves, control such weeds as redroot, wireweed, redshank, and black nightshade. They also control young spurrey. The chief disadvantage is that the salt does not control fathen and is too damaging for use in turnip crops.

Weed Control The only two weed species which are sufficiently aggressive to cause complete crop failure in the county are

redroot and willow weed. These two weeds have caused many farmers to forsake forage cropping, and others have modified their cropping technique. Certain methods may be used to combat weed invasion: 1. Dairy farmers in the more fertile northern end of the county, where the weeds are more serious, have the best weapon for. combating these weeds in the growing of maize. The competition of this crop , with the weeds has already been referred to. 2. On many farms weed competition can be reduced to insignificant proportions by avoiding the growing of two consecutive crops on the one paddock. The first crop is usually relatively weed free, except on some of the higher fertility farms. 3. Early sowings of brassica forage crops have been helped by allowing the crop to cover the ground before large-scale germination of weed seedlings has begun. In the northern parts, of Matamata County redroot seed does not germinate in large quantities before October in an average season. Turnip and chou moellier crops established in the last week of September appear to have a better chance of success.

4. It has already been stated that generally insufficient time is given to seedbed preparation. When crops are to be sown after the first week in October in the north zone the seedbed should receive at least three light chain harrowings at 5- to 7-day intervals to destroy surface-germinating weed seeds. Heavy harrows, which bring fresh seed to the surface, should not be used.

5. Redroot and willow weed seedlings can be destroyed when TCA at 15 lb. per acre is applied to the soil as the last operation immediately after the crop is sown. This treatment is extremely effective when the soil is wet or when light showers follow application within about 3 days. Under dry' conditions the treatment is useless. Under the correct weather conditions many Matamata farmers have used the treatment successfully, and anyone who is prepared to wait for suitable weather before sowing his crop could apply this treatment with reasonable expectation of success. 6. Seedlings of redroot and willow weed in maize crops can be destroyed with 2,4-DB hormones at 1 to 2 lb. acid equivalent per acre. After sowing and up to about the 6 in. stage of growth maize may safely be harrowed to control seedling weeds. This should be done during, the hot period of the day, when the maize plants are not turgid with water. From the foregoing it can be seen that weeds pose a problem on many farms where forage crops are desired, but the problem can be, and in many cases known to the author has been, solved. Pests and Diseases Forage crops are liable to be attacked by a variety of pests and diseases not all of which warrant control measures. One of the worst pests is the springtail, and many brassica crops have been destroyed while in the seed leaf stage by this insect. Where a crop has been lost to this pest resowing is more likely to be successful if J lb. of lindane per acre is sown with the seed. The springtail is a tiny insect smaller than a pinhead and difficult to see. If there are no springtails, but crops are lost in the same growth stage, especially in early November, the grassgrub beetle may be responsible. This is one more reason for early sowing of crops so that they are past the seed leaf stage by November.

Another pest which does its worst damage in the drier seasons, when crops are more vital, is the cabbage aphid. This insect sucks the sap of members of the cabbage family, including turnips, swedes, chou moellier, and kale. Under humid conditions the insects multiply rapidly and can destroy crops within days if the soil is dry. Aphids can be checked by

| lb. of lindane per acre, but high pressures and fine jets must be used to contact the insects, which accumulate almost entirely on the undersides of leaves. Other insecticides also show promise in aphid control and further development in such control can be expected. In Australian literature malathion at 2 fl. oz. of 50 per cent emulsion per acre is recommended in preference to lindane.

If swedes are being, grown, the aphid-resistant varieties Calder and Sensation may be tried. White butterfly, diamond-backed moth, shield bug, and a species of cut worm are also commonly found on brassica crops in the county, but crop damage is seldom severe.

On maize crops cut worm and army worm caterpillars can cause severe damage. Several cases have been noted where 7 ft.-high maize crops have been completely defoliated by these pests in less than a week. If the caterpillars are noticed among seedlings of maize, the area may be treated with 1 lb. of 100 per cent DDT per acre. Usually, however, it is in the semimature crop that the caterpillars are first seen, generally about the end of January. The spreading of baits by hand is then the only feasible method of control. Baits have been used with spectacular success in mature maize crops in the Matamata district. The baits used are 30 lb. of bran and | lb. of 10 per cent DDT per acre, or, 30 lb. of sawdust, 5 lb. of molasses, and | lb. of DDT. All the major soils in Matamata County are liable to produce mottled

heart disease of swedes because of the marginal state of soil boron supplies. Turnips are less likely than swedes to suffer, but chou moellier sometimes produces internally cracked and discoloured stems owing to the same, cause. Though not universally practised, the application of 8 lb. of commercial borax per acre a few days before seed is sown is usually warranted. In mild autumns and winters softrot diseases, locally known as collar rot, stem rot, etc., sometimes cause heavy losses in swedes and in chou moellier crops which have been lightly fed off in autumn for winter recovery. Aphid and shield bug damage of chou moellier also appears to predispose the crop to soft-rot diseases. No fully effective preventives or cures are known for these diseases, but they can be reduced by sowing later-maturing crop varieties. Club root disease is common in most parts of the county, but seldom produces crop failures. Where it does a club root-resistant crop such as chou moellier should be grown. Other pests and diseases are common, but since they are not usually of great economic importance, discussion of them is not warranted here. There are, however, answers to almost all the pest and disease problems and all other growing problems of forage crops, and the application of these solutions will make the growing of forage crops fairly reliable in Matamata County.