The on-farm water supply on the Mid Canterbury irrigation schemes of 230 litre/sec for one day per week for every 80 hectares of farm area has traditionally been considered capable or irrigating only about one half or two thirds of the total farm area. Many farmers have border dyked about this proportion of their farms leaving the remainder dryland. In 1978 a farmlet with the whole area prepared for irrigation but still subject to the normal limitations of the rostered water supply was set up at Winchmore. Half of the area is in cash crop. Through a careful selection of crops and sowing dates each crop can be irrigated for maximum yield without exceeding the water allocation. On the remainder of the farmlet half the area is in grass clover pasture and half in lucerne. The water supply permits this to be irrigated at four weekly intervais or more frequently before and after the period of crop irrigation. Crop production on the farmlet has only been average. For instance wheat and barely have generally yielded between 3.5 and 5 tonnes per hectare. Soil moisture monitoring suggests that limitations have not been imposed by the irrigation regime itself but by such factors as late sowing the crop or undersowing with pasture. Over the three year stand life herbage production has averaged over 11000 kg/ha with annual yield of lucerne exceeding that of grass/clover pasture in the first season ex crop. Stocking rates between 13 and 15 ewes/ha measured over the whole farm area or 26-301ha on spring grazing area have been adopted with large variations in production. With recent changes in the relative economics of sheep and cropping it has been decided to increase the emphasis on the crop aspect of the farmlet. The cropping area has been increased to twothirds. The farmlet is still run under the limitations of the rostered water supply but water may now be transferred from the herbage to crop at critical times. At the expense of small losses in herbage production crop yields will be increased substantially by eliminating such practices as late sowing dates and undersowing. Keywords: Irrigation, roster, crop, stock.
The on-farm water supply on the Mid Canterbury irrigation schemes of 230 litre/sec for one day per week for every 80 hectares of farm area has traditionally been considered capable or irrigating only about one half or two thirds of the total farm area. Many farmers have border dyked about this proportion of their farms leaving the remainder dryland. In 1978 a farmlet with the whole area prepared for irrigation but still subject to the normal limitations of the rostered water supply was set up at Winchmore. Half of the area is in cash crop. Through a careful selection of crops and sowing dates each crop can be irrigated for maximum yield without exceeding the water allocation. On the remainder of the farmlet half the area is in grass clover pasture and half in lucerne. The water supply permits this to be irrigated at four weekly intervais or more frequently before and after the period of crop irrigation. Crop production on the farmlet has only been average. For instance wheat and barely have generally yielded between 3.5 and 5 tonnes per hectare. Soil moisture monitoring suggests that limitations have not been imposed by the irrigation regime itself but by such factors as late sowing the crop or undersowing with pasture. Over the three year stand life herbage production has averaged over 11000 kg/ha with annual yield of lucerne exceeding that of grass/clover pasture in the first season ex crop. Stocking rates between 13 and 15 ewes/ha measured over the whole farm area or 26-301ha on spring grazing area have been adopted with large variations in production. With recent changes in the relative economics of sheep and cropping it has been decided to increase the emphasis on the crop aspect of the farmlet. The cropping area has been increased to twothirds. The farmlet is still run under the limitations of the rostered water supply but water may now be transferred from the herbage to crop at critical times. At the expense of small losses in herbage production crop yields will be increased substantially by eliminating such practices as late sowing dates and undersowing. Keywords: Irrigation, roster, crop, stock.
Six lucerne cultivars (Wairau, Rere, WL318, AS13R, Pioneer 521 and Saranac) were evaluated in Mid Canterbury since 1979 under two contrasting management systems; dryland grazing and irrigated ‘cut and cart’. In addition, the effect of strategic aphicide application was examined on the irrigated system. Principal interest in both these studies centred on Rere, the N.Z. bred aphid resistant cultivar released in 1979. All the cultivars established well and for the first three years no consistent differences between cultivars in herbage yield were recorded under either system. However, in the third full production season (1982183) substantial differences in herbage yield began to develop between the cultivars, and the tvzd cnn!inued i:: the fGiiit:l arid fiiiai production season (1983/84). By the end of the fourth season Rere was clearly the lowest yielding cultivar under both systems, producing only 69% and 29% of the yield of the highest producing cultivar (Wairau) under dryland and irrigated conditions respectively. Application of aphicide gave no herbage yield benefit on any cultivar in any season. Keywords: Medicago sativa, irrigated, non irrigated, cultivars, aphicide, Wairau, Rere, WL318, AS 13R, Pioneer 521, Saranac
Herbage mass, moisture content and in vitro OMD of autumn saved ryegrasslwhite clover pasture grown on irrigated flats in the Upper Waitaki Basin were monitored over four winters from 1979-82. During the winter of 1981 and 1982 the effect of closing date and nitrogen application was examined. In addition Merino ewes were all-grasswintered from mid June to mid September without supplements on a feed allowance of 1.2 kg DMlhd.day to determine effect on liveweight. Mean herbage mass and OMD loss from mid May to early September were 25 and 13% respectively and the moisture content of the pasture decreased from 73 to 45%. Herbage mass by mid May was less for March and April than for February closing, although for March closing this deficit was offset through use of nitrogen. Approximately 50% of the sward was frosted by mid September with OMD of the f-m_.c-.tAcd rnwn,rti.nIVn.I IC,*“O”/.\ ,v, .-vrvrmlllnv-~-r~C~.ul-l~ +L-U k0-1.a.y. Ewe liVeWeightS initialiy ieii but recovered during the latter half of the winter despite the constant fall in herbage OMD. Sward desiccation exceeded loss in digestible herbage mass over the winter, suggesting increasing rather than decreasing food value. Keywords: High country, herbage losses, frosting, in-vitro OMD, irrigated pasture, autumn-saved-pasture, nitrogen, feed value, all-grass-wintering, Merino ewes
ocksfoot (Dactylis glomerata L.) is the second most commonly sown grass after ryegrass (Lolium spp.) in New Zealand. Some characteristics restricting its performance in pastures have been improved in a new variety ‘Grasslands Wana’ cocksfoot, released in 1980. A series of trials at Taupo, Woodville, Central Wairarapa and Eastern Southland showed that under sheep grazing Wana can be established as the dominant component of the sward. It was concluded that Wana has potential as both a dry and moist hill country pasture grass and particularly in dry environments may have advantages over the species currently present.
White clover populations from Europe and New Zealand together with ecotypes collected from old pastures in Southland-Otago were evaluated as spaced plants at Gore. Plants were screened for herbage production and morphological and flowering characteristics. The Southland ecotypes and North Island hill country material are adapted to active growth in spring and summer. Their dense growth habit ensures continued production of branched stolons from nodal meristems which is necessary for high clover yield and persistence under intensive sheep grazing. In this region flowering characteristics are unimportant in relation to agronomic performance. Some largerleaved Huia and French lines have high-yielding features which are evident during autumn under lenient grazing. Hybrids between superior plants showing adaptive and high yie!ding features are being screened in order to select new types with the desired characteristics. Keywords: White clover, Trifolium repens L., plant breeding, southern region, ecotypes, growth, morphology.
Hill country pasture was sprayed with low fates of the herbicides paraquat, sethoxydim or Dowco 453 in late November. Legume content of the pasture 6 weeks after application increased from 29 to 61%, and from 12 to 31% in January 1983 and 1984 respectively. The chemicals reduced dry matter yields by 16 and 45%, 6 weeks after treatment, but yields were not reduced in subsequent harvests. The chemicals reduced dead matter content, strongly suppressed grass seed head production, increased clover seed head density and increased in vitro digestibility. Sethoxydim at high rates 150 g/ha reduced perennial ryegrass (Lo/km perenne) content, but Dowco 453 increased perennial ryegrass and decreased browntop (Agrosfis tenuis) content. The effect of clover content and dead matter on sheep diet selection is shown and the implications of these results for management of hill country pastures in moist si;m.mers are discussed. Keywords: herbicide, paraquat, sethoxydim, Dowco 453, white clover, Trifolium repens, hill country, in vitro digestibility, perennial ryegrass, Lolium perenne ryegrass, Lolium perenne browntop, Agrostis tenuis.
Research into chemical pasture renovation was pioneered by NZ scientists in the 1960’s but the technique was not widely adopted at that time. Subsequent work has confirmed that white clover (Jrifolium repens L.) is a poor competitor against browntop (Agrostis capillaris L.) for phosphate. This has implications regarding nitrogen fixation. Pasture renovation also provides an opportunity to introduce preferred pasture grasses, free of competition from resident grass species. White clover is now recognised as a high-quality feed for livestock. Work is reviewed showing the correlation between liveweight of ewe hoggets and subsequent breeding performance and that white cloverdominant pasture was superior i0 ryegrass-dominant pasture for flushing breeding ewes. In field-scale testing, the plant growth regulator mefluidide suppressed seedhead formation in pasture grasses and gave substantial, though regionally variable, liveweight gains in lambs, beef cattle and deer. In limited evaluation with dairy cows changes in pasture herbage have not been matched by improved milk or milkfat yield. Keywords: Chemical pasture renovation, fertiliser utilisation, pasture quality, chemical plant growth regulator
Dairying on border dykes is proving to be a viable alternative land use in Canterbury and North Otago. This 1984-85 season will see 20 border dyked farms in Mid-Canterbury area now dairying that have been converted from sheep to dairy in the past 6 years. The reason for this is simple. All the theoretical advantages of dairying on free draining irrigated land are real. I quote the Chairman of the New Zealand Dairy Board when questioned at Ruakura Farmer’s Conference this year about the industry of growth in this region’. He said, “I wish I had never gone to see the area - it’s attractive land offering immense opportunity”. We are now in our fifth season of production. I am finding the challenge of increasing production every bit as exciting now as it was in the first year.
Persistency and productivity of irrigated ‘Grasslands Matua’ prairie grass pastures were measured under four sheep grazing regimes, frequent or infrequent (grazed 3 weekly or 6 weekly) coupled with lax or severe defoliation (grazed to 7.5 cm or 2.5 cm). Matua was also compared with ‘Grasslands Nui’ and Yates ‘Ellett’ perennial ryegrasses under frequent severe grazing. These are interim results from two experiments sown in successive years. There were few consistent differences among grazing treatments of Matua pastures. However, the Matua content of pastures tended to be less under frequent grazing. In the third year of Experiment 1, infrequent grazing to 2.5 cm resulted in significantly hlgher annual production than other Matua treatments. ‘Eiiett’ ryegrass tended to outyield ‘Grasslands Nui’ in the first year but subsequently there was little difference in yields. The dry matter production of ‘Ellett ryegrass was not significantly different from the best Matua treatment in any year. More herbage was lost through trampling and decay in the infrequently grazed Matua pastures than in the frequently grazed Matua or ryegrass pastures. After three years, all Matua pastures contained more weeds and more volunteer grasses than did ryegrass pastures. Keywords: prairie grass, Matua, ryegrass, Nul, Ellett, grazing management, lax grazing, severe grazing, irrigation.
To test the performance and nutrient requirements of Grasslands Maku lotus (Lotus pedunculatus) on high country acid soils under tussock grassland, the effects of phosphorus (P), sulphur (S) and lime on lotus and clover yields were measured in cut plots on sites ranging in altitude from 700 from 1200 m on the Remarkables Range (topsoil pH 5.5 - 4.8), and on the East Otago (Lammerlaw-Lammermoor) uplands (topsoil pH 5.2 - 4.4). On the Remarkables, mean annual yields for P + S treatments decreased from about 7000 to 3500 kg DMlha and on the Lammerlaw- Lammermoor sequence the decrease over the same altitude range was from about 2000 to 200 kg DMlha. Soi! !pSt va!lJes fgr S 2nd p were !c):l’ cu.+. -C1A1,* 1 LQU-lml,,-l-l‘r-l*I*~, ““-L’S-L-II-II-II-~-I^lll-”“-l sites: S-deficiency was so severe that there was very little response to P until S was added and in most cases there was little response to S in the absence of P. On the Remarkables soil test values were more variable and lotus yields were closely related to soil test values. Fertiliser requirements of lotus were generally similar to those of clover, but clover occasionally continued to respond to higher rates of P than lotus. In contrast to clover, lotus showed little or no response to lime, except at the highest altitude (i.e. lowest pH) on the Lammerlaws. In both Remarkables and Lammerlaw-Lammermoor sequences lotus and clover yields were similar up to 1000 m but above this altitude lotus production exceeded clover on the Remarkables. On the Lammerlaws yields dropped off sharply at the highest altitude but clover yields where lime was applied were significantly higher than lotus. Decreasing lotus yield with increasing altitude is attributed to increasing severity of climate (probably low temperatures). The lower yields and greater decrease on the Lammerlaws suggest that the limitations are more severe there than at corresponding altitudes on the Remarkables. Keywords: Lotus, high country, fertiliser, lime, climate
Observations of blocks oversown with Maku lotus in the Otago tussock grasslands have indicated that the potential yields are not being obtained as a result of low seedling establishment and limited spread of established plants. Satisfactory establishment is dependent on correct aerial oversowing techniques and suitable site preparation. Inoculation with rhizobia is essential for nodulation on most areas of the tussock grasslands and the present recommendation is to slurry-inoculate seed at up to 5times the normal manufacturers rate. The incorporation of 10% (w:v) gum arabic in the slurry improves viability of rhizobia and allows seed to be stored for 1-2 weeks before sowing. Vegetative spread of established plants depend on growth of rhizomes during the summer/autumn period. This rhizome growth is sensitive to time of defoliation of the sward. Defoliation as early as the start of January reduced the amount of rhizome present in April while early-February or early-March defoliation virtually eliminated rhizome growth. In sparse swards of Maku lotus where maximum spread of existing plants is required it is recommended that grazing be avoided over this critical period. Where adequate plant density has been obtained either through the use of correct seedling establishment techniques or earlier management for rhizome spread, it is not necessary to adhere to this recommendation and swards can be rotationally grazed over the summer/autumn period. Seed production of Maku lotus is limited, particularly at higher altitudes and on shady aspects, and the technique of natural reseeding has limited application in these tussock grasslands. Keywords: grazing management, inoculation, Maku lotus, rhizome, seed production
The development of irrigation on farms in Mid Canterbury has generally been carried out on a paddock basis, as cheaply as possible and with little thought to farm design leading to systems which are labour intensive and do not use the water efficiently. With increasing pressure on our water supplies and the need for farmers to irrigate extra land recent work has been directed towards increasing the efficiency of water useage. It has been found that by increasing the flow of water down the strip from 180 //s to 300 /Is that 11% extra land can be irrigated with the same volume of water, If the border-strip length is shortened from 300 m to 200 m the irrigation rate will increase from 0.73 ha/hour to 0.91 ha/hour when using a flow of 230 /Is and a group of four strips. When the increased flow rate and the decreased strip length are combined there is a greater effect than when the two are applied independently. iAlrtn better layouts and increased watering efficiency greater areas of individual farms are being irrigated and the irrigation level is being reduced. Keywords: Irrigation, border-strip, efficiency, farm irrigation
The wide diversity of soil, topography and climate enables South Canterbury’s 2300 farm holdings to produce a wide range of livestock, arable and horticultural products. The 3 counties (Strathallan, Waimate and Mackenzie) cover a land area of nearly 1.4 million hectares stretching between the Rangitata River in the north to the Waitaki River in the south and the coast in the east to the southern divide in the west. Approximately 75% or 1 million hectares are farmable falling into land use capability classes l-7 (Table 1). Of this approximately 200,000 hectares or 20% are in land use classes 1-3 and can therefore be considered as potentially arable. The bulk of this land occurs on the coastal plain and easier downlands in the counties of Strathat!an and Waimate. The balance of approx uuu,UUU hectares or 80% are in land use classes 4-7 being divided between 600,000 hectares of high country and 200,000 hectares of downland. Over two-thirds of the high country lies in the Mackenzie county while the downlands which can be further divided into wet and dry occur in all counties between the coastal plain and the inland high country.
In early 1970 the few pioneer deer farmers were being watched while they learnt the techniques of domesticating the wild deer. Deer farmers are still being watched though most are not now pioneers. The systems have been studied, learnt and basically understood. The last 10 years have seen rapid growth in numbers of farmers involved and animals kept. Local Mid and South Canterbury figures have increased dramatically (Table 1). Nationally 2,000 (plus) operators farm 200-250 thousand deer. Does that have 38,000 farmers still not involved? To those early into the business have come the financial rewards they deserve. For them, there was little information from research, less from advisory services and much sceptiscim from financiers and fellow farmers. Fortunately this has changed. Many MAF personnel, veterinarians, researchers and stock and station people are well qualified to assist the potential deer farmer
Finishing iambs to produce a bigger dollar sign is a challenge to all sheep farmers. Around the beginning of 1980 life had become a little dull and we thought a change was necessary. So, after some haggling a 620 ha property was bought. It tended to be a little bedraggled as we could only keep three mobs of sheep apart but after putting on sixty-five gates, digging in thirty-one strainers and mending fifty-four broken wires, we ended up with forty-three paddocks ranging in size from one to twenty-five hectares. The property lies on the coast some 8 kms north of where the Waitaki river flows into the Pacific Ocean. The soil is of the poorer Steward type, with a pH of 5.5 and phosphate reading of 5-8, and is situated at the lower end of the Morven-Glenavy irrigation scheme. The property had 230 hectares border dyked, with pasture quality ranging trom a good ryegrasslwhite clover to a very hungry looking browntoplhair grass/sub clover stony mess. The dryland had a lot of sub clover throughout, but did not produce unless it rained for three days or the irrigation water got loose. The first lambing in 1980, with 6300 sheep to the ram resulted in about 500 dry ewes and a 93% lambing. We did our best to fatten these lambs but because there wasn’t enough good pasture and we were hoping to make some hay, a lot of these lambs were killed around 11.5 to 12.5 kg returning some $14 to $16 per head.
Continuous stocking was compared with intermittent (two paddock) and rotational (six paddock) grazing at low, medium and high stocking rates equivalent to 1.0x, 1.5x and 2.0x conventional rates for oversown tussock country (500 mm annual rainfall). ‘By the sixth year liveweight gain/ha from Merino wether hoggets was improved 26% by intermittent and rotational grazing at medium stocking rates from that at conventional stocking rates. A strong interaction was demonstrated, with advantage in liveweight gain from intermittent and rotational grazing strengthening with increasing stocking rate. Total vegetative cover (75.8%) remained unchanged. Cocksfoot increased under low stocking while ryegrass increased under high stocking. A 60% overall loss in ryegrass during 1982 was attributed to unusually low winter soil temperatures. White clover cover was affected more b y climate than by grazing. A!!hough ?here *were interim differences, herbage production by the sixth year was similar for all treatments. Keywords: Tussock country, oversown, grazing, stocking rate, subdivision, pasture development, utilisation, Merino, liveweight.
The balance between the litter and animal excreta pathways was varied by imposing a range of sheep grazing intensities on a dryland ryegrass-white clover pasture for 3 years. In contrast to laxly grazed treatments, hard grazed treatments lost soil carbon and nitrogen. Greatest overall losses occurred in the driest year, and lowest losses occurred in years of greatest pasture growth. The importance of allowing some litter cycling, by avoiding continual hard grazing is discussed. Keywords: N-fixation, soil nitrogen, grazing, carbon, balance, litter, pasture.
Pasture production and water use data are presented for a border strip irrigation trial in the Upper Waitaki Basin. Pasture development on the shallow, poorly structured Mackenzie soil was slow and irrigated pasture remained clover dominant for 6 years. With irrigation at 25% awe pasture herbage production over 3 years of this initial development stage averaged 7.2 t DM/ha/yr, 5 times more than improved dryland pasture. Grazing days (12 - 19 month old ewes) provided during the September to April growing season were 960 under dryland conditions and 5940 under irrigation at 25% awe. Of the 3 irrigation treatments (irrigation at 0%, 25%, 50% awe), irrigating at 25% awe was the most efficient giving near-maximum pasture production and the greatest herbage response per irrigation, Mean annual water use efficiency at 25% awe was high (63%) and irrigation water requirement low (470 mm) for such a naturally, highly permeable soil and was probably due to soil compaction by earthmoving machinery during border strip preparation. Keywords: Irrigation, high country, Mackenzie soil
An indirect method has been used to estimate losses of nitrate nitrogen from sheep-grazed pastures on a free-draining soil. The drainage component of a soil water balance was assumed to move nitrate, at the concentration of the soil solution between 30 and 45 cm depth, to below the zone of uptake by plants. Losses of between 60 and 80 kg N/ha were calculated to be leached from control ryegrass-clover pastures in each of the winter drainage seasons studied. More than 85% was lost by early August, even though 40% of drainage occurred after this date. Extra leaching losses in the first season appeared to account for the equivalent of 45% of either the 110 or 450 kg N/ha added in the two fertiliser N treatments. In the second season losses were less than 25%. Removal of clovers from the sward reduced leaching estimates to little more than half those below the control pasture. Estimates confirm the large size of leaching losses under intensive grazing. These have implications for agricultural production and groundwater quality. Keywords: Leaching, nitrate, sheep-grazed, pastures, fertiliser, nitrogen, clover-free, water balance, drainage
The behaviour of Merino wether hoggets grazing an existing management experiment at Tara Hills High Country Research Station was studied during summer 198111982. The experiment compared three stocking rates and three management systems (continuous, two paddock intermittent grazing, six paddock rotational). The daytime distribution and activity of the hoggets, dung distribution, and Olsen-P levels of topsoils were recorded on ten altitudinal strata within each of the nine treatment areas. Dung frequency was more closely correlated to grazing distribution than to either resting or total animal distribution. This is contrary to the generally accepted belief that dung accumulation is associated with resting behaviour. Increasing stocking ra?e !ed ?o a more even grazing and dung distribution. Subdivision by itself did not improve the evenness of distribution although it may have enhanced the stocking rate influence. There was little correlation between dung frequency and soil Olsen- P levels, especially outside the night camp areas. This indicates the importance of factors such as plant uptake and herbage consumption in the phosphate nutrient cycle. Olsen-P levels were consistently higher in the high stocking rate paddocks relative to the low stocking rate. Levels in the medium stocking rate fluctuated between these two. The implications of these findings in regard to the effects of intensification of farming in the high country on nutrient cycling and fertiliser requirements are discussed. Keywords: animal behaviour, dung distribution, tussock grasslands, phosphate, grazing management.
This paper reviews the role Matua prairie grass can play on pastoral farms, and covers establishment and utilisation problems. A management package is presented based on recent practical experience. It is felt that finally, many years after its release, there is now a package which will enable most farmers to use Matua while avoiding the problems that have plagued users in the past. Keywords: Matua, prairie grass, dryland, pastoral farming
Infertile hill country grasslands are a vastly under-utilised pastoral resource in New Zealand. Three years of trial results on this class of land in eastern Southland are summarised. Five grasses (Grasslands Nui ryegrass, Wana cocksfoot, Matua prairie grass, Roa tall fescue and Maru phalaris) were oversown together with Huia white clover and subterranean clover. These were compared with a resident pasture, all under two fertility levels and two rotational grazing managements, and with unimproved pasture. The use of fertiliser and rotational grazing doubled the productivity of the unimproved rangeland to ca. 10,500 kg DMlhalyear. The addition of white clover increased yield to 12,000 kg, and improved grasses increased this further to 14,000 kg. Keywords: agronomy, fertiliser, grasses, grazing management, hill country, oversowing, pasture composition, pasture yield.
Pasture renovation using Conservation Tillage including herbicide is a fast, efficient method of improving low producing pastures. The advent of Glyphosate has enabled pastures to be renovated without the need for a break-crop and thus minimal loss of production. Because of the rapid and substantial increase in carrying capacity, the cost of renovation can be recovered within 1-2 years of sowing. For these reasons pasture renovation using Conservation Tillage is becoming accepted practice in the hill and high country. Keywords: Pasture renovation, conservation tillage, hill country, glyphosate.
An existing grazing trial on an irrigated Wakanui silt loam at Lincoln College, Canterbury, was sampled at five consecutive grazings (January to July, 1983) to determine the effects of pasture utilisation on herbage composition and in vitro digestibility of regrowth. Rotational grazing of sheep at two stocking rates, high (27.5 ewes/ha) and low (17.5 ewes/ha), resulted in different levels of utilisation. Low utilisation (27%) produced a sward with a high dead material content (44%) and low in vitro digestibility of the whole sward (<70%). The high stocked sward (utilisation, 60%) had a greater percentage of green material (83%) but total green yields were only half those at the low stocking rate. The in vitro digestibility of the sward under the high stocking rate was Z-70%, mainly as a result of only a small proportion of dead material with low (46%) digestibility. Keywords: pasture utilisation, herbage composition, dead matter, green herbage yield, in vitro digestibility, stocking rate
Maku lotus plants were grown in snow tussock grasslands at 1460 m altitude on steep ungrazed slopes. A total of 960 plants were transplanted in spring 1980 to five sites. In March 1984 survival was 72% and 68% on two NW sites and 66%, 56% and 46% on three ESE sites. Survival rates did not differ between 100 and 300 kg/ha sulphur enriched superphosphate applied in the transplant year, but dense native vegetation appeared to contribute to poorer survival on the eastern slopes. Mean lotus plant size, expressed as an index of ground spread was consistently larger on NW than on ESE, and in February 1984 was three times larger (1422 cm* cf. 429 cmZ). Mean DM yields per plant in February and March 1984 were from 1.3 to 3.0 times greater on NW sites. Ground spread indices and D.M. yields showed a response to the higher rate of fertiliser on some sites only. Higher air and soil temperatures on NW aspect, particularly in early spring and In autumn favouied a longer period of growth compared with E.S.E. The trials showed that Maku lotus could be a valuable herbage resource on warmer northerly aspects above 1000 m. In addition, the high variability amongst l.otus plants suggested that production for such cool environments could be improved by selection within existing populations. Keywords: Maku lotus, Lotus pendunculatus, aspect, high altitude, persistence, plant performance, plant selection.
Effects of two different fungicide seed treatments, inoculation of seed with teliospores of the head smut fungus (Ustilago bullata Berk.), and five different autumn sowing dates, on establishment of prairie grass (Bromus willdenowii Kunth cv. ‘Grasslands Matua,‘), were examined in a field trial. Seedling establishment was increased by thiram seed treatment and decreased by inoculation of seed with U. bullata. Greater numbers of seedlings established from early sowings, when soil temperatures were higher, than from late sowings. Suitable seed treatments to increase the likelihood of successful establishment of prairie grass are discussed. Keywords: Bromus willdenowii, seedling establishment, seed treatments, thiram, Ustilago bullata, sowing dates, soil temperatures
Keywords: seedlots, Lolium spp, germination, blind seed disease, heating damage, physical purity, weed seed contamination, seed certification.
On light soil in Canterbury, a Nui ryegrass/Matua prairie grass (area proportion 7030) irrigated farmlet stocked with 20 Coopworth ewes plus 5 ewe hoggetslha grew 15.0 t DMlha. From 190% survival-to-sale of lambs, mean lamb live-weight was 30.6 kg to give a calculated meat yield of 550 kg/ha. Ewe replacments grew to 59 kg in their second summer. On the same site in a later year and comparing NuilMatua (area proportion 50:50) with Nui only farmlets at stocking rates of 13 and 16 Coopworth ewes/ha, the pastures grew 11.2, 11.2, 10.2 and 9.9 t DMlha respectively. The highest yielding system was NuilMatua - 16 ewes/ha, where from 181% survival-to-sale of lambs, mean liveweight was 26.8 kg to give a calculated meat yield of 375 kg/ha. Nui alone - 16 ewes/ha provided for a calcu!a!ed meat yie!d of 326 kn,yfh,,r,-, with ewes in that system being 3.8 kg lighter than at their mating time. The features of Matua were its superior cool-season growth and, under dryland condition, its superior feeding quality in summer. Management was rotational grazing in a ten paddock system with short duration of grazing (about 4 days) for Matua pasture. Keywords: grazing system, lamb meat production, Lo/&m perenne, Bromus willdenowii
Swards under rotational grazing by cattle (RGC) and under set stocking by sheep (SSS) were sampled every 2 months for 3 years, and white clover stolon dissected into 3 vertical classes; aerial, surface and buried. Despite large differences in yearly herbage production, sward structure, white clover content, total stolon weight and proportioning of stolon among the vertical classes between the sites, the greatest differences in distribution of stolon among the vertical classes were associated with month of sampling and this was consistent among years at both sites. These results indicate that over a 3-year period, in both swards studied, the white clover component underwent an annual cycle of burial of stolons in winter, re-emergence of growing points in spring and surface stolon development over summer. Keywords: white clover, Trifolium repens, stolons, vertical distribution, seasonal variation.
Pasture production was measured on stony soils at Hororata, Canterbury, at various distances parallel to an established tree shelterbelt. Windrun and temperatures were recorded in a sheltered zone at 3 tree heights distant from the trees and in an exposed zone, 12 tree heights distant. A 60% improvement in dryland pasture production was recorded in the sheltered areas over 3 years. The sheltered zone was half as windy as the exposed zone and soils tended to be warmer at times from October to March. More soil moisture was probably lost from areas most exposed to wind, and this most likely contributed to depressed pasture growth. Keywords: wind, shelter, dryland pasture production.
Reduction in water content of a soil increased the concentration of ammonium and nitrate in solution, but had no effect on the concentration of phosphate. The corresponding reduction in the quantity of phosphate in solution caused an equivalent reduction in the response of ryegrass to applied phosphate. Keywords: soil solution, soil water content, phosphate, ryegrass, nutrition.
An automatic rain-out shelter and an oscillating sprinkler irrigator were used to give contrasting wet and dry soil moisture regimes during summer in ryegrass swards, which had been differentially mown (7.5 ems vs 2.5 ems) during spring to create differences in tiller density. Swards with a higher tiller density before drought had a higher tiller density after drought. Although there was no effect of spring defoliation on summer production, there was a trend for pastures with a higher tiller density to recover more quickly after drought. The effect of water stress was to reduce herbage yield to only 8% of that of irrigated treatments. This was attributed to reductions in tiller density and rates of leaf extension and -~rnrn---r=,.+.n.ce. Water stresa- also increased the kiieis of lamina soluble sugars. Rewatering after moisture stress resulted in compensatory growth which partly offset the yield loss incurred during stress. Keywords: Spring grazing management, dryland, water stress, perennial ryegrass, sward dynamics, lamina soluble sugars.
Because of the many problems experienced in Hawkes Bay with traditional ryegrass pastures - drought, grass grub, stem weevil, ryegrass staggers - a research programme to evaluate tall fescue was initiated. Four short term trials have compared the nutritive value for sheep of two tall fescue cultivars (Roa and Demeter) with Nui ryegrass, all sown with white clover. All pasture types had similar quality for finishing lambs, although regrowth after a silage cut was better than previously grazed pastures, especia!!y for Nui. In the droughts of 1982 and 1983, tall fescue pastures were superior to those of Nui in both quantity and quality of feed for ewes prior to mating. This advantage resulted in an average of 18 more lambs being born per 100 ewes mated. Provided it persists, continues to produce well, and does not cause serious animal health problems under intensive sheep grazing, these results show that tall fescue should have an important role to play in Hawkes Bay and similar environments. Keywords: tall fescue, perennial ryegrass, lamb production, ewe production.
Nine paddocks (0.85 hectares each) of ryegrass-white clover pasture were divided in half and one half of each paddock sprayed,with 0.15 kg ai mefluidide per hectare in mid-October. All paddocks were grazed 7-9 days after spraying and then rested for a further 14-20 days. A 7 week grazing trial using 8 pairs of idential twin cows was then conducted. All cows received an equal herbage allowance of 40 kg dry matter per head daily. Equal areas were offered to each treatment group and extra cows used to adjust the grazing pressure where necessary. Mefluidide depressed pasture growth rates by 29% for 3-4 weeks after spraying. Subsequent growth rates did not differ significantly between sprayed (S) and unsprayed (U) pastures. Pasture quality was similar for both treatments in the second round of grazing (late November and early December), but in the third round (mid-December) sprayed pastures were more leafy, less stemmy, had higher N concentrations and were more digestible than unsprayed. This was not reflected as differences in the yields of milk, milkfat or milk protein between treatments. The net effect of spraying with mefluidide was therefore to decrease the carrying capacity of the sprayed area used in the grazing trials by 76 cow days compared with the equivalent unsprayed area. This would have resulted in the production of approximately 59 kg less milkfat from 2.5 ha over a 7 week period. Keywords: Mefluidide, Embark 2-V , pasture growth, pasture quality, milk yield, dairy cows, milkfat, nutritive value.
The responses of pasture and lucerne to irrigation were compared in 2 series of trials (1976-1981 and 1980-1984) on 8 different Canterbury soils. Pasture responses were also measured on a further 4 soils. With unrestricted irrigation, pasture yields were similar (about 11 t DM/ha/yr) on 8 of the 12 soils. These soils ranged from stone free Wakanui clay loams to a very stony Balmoral silt loam. Two soils yielded at a higher level, and two very stony soils significantly less. Non-irrigated lucerne yielded more than pasture in “average” Canterbury seasons, but less in two exceptionally dry years. With irrigation, lucerne yielded more than pasture for the first 2 or 3 years but tended to decline thereafter. The paper discusses irrigation strategies for border strip irrigated pastoral farms in times of water restrictions. It concludes that maximum DM production is likely to be obtained by spreading the available water over all irrigated pasture untii the irrigation interval reaches 23 to 28 days on shallow stony soils and 34 to 38 days on higher water holding capacity soils. Keywords: pasture production, lucerne production, irrigation, irrigation interval, Canterbury.
The pasture and animal productivity of established high producing pastures in the Waikato has been compared with newly sown pastures based on recently released herbage cultivars. The established pastures were a mixture of Nui perennial ryegrass, Paspalum dilatatum and Htiia white clover. The new cultivars tested were Ellett perennial ryegrass, Wana cocksfoot and Roa tall fescue, each sown with Pitau white clover. The main advantages of the new pastures containing Ellett were in increased autumn and winter herbage production, higher stock carrying capacity and lower hay requirements. The Ellett pastures had higher ryegrass content and lower weed levels than the older pastures. Wana cocksfoot when grown with Ellett ryegrass increased in content over the experimental period, especially under less intense grazing pressure although some frost damage was evident in winter wi!h a possible lowering of herbage nutritive value of the mixture. Tall fescue pastures only showed occasional merit in summer-autumn periods under the less intensive grazing regime. Keywords: established pastures, Nui ryegrass, Ellett ryegrass, Wana cocksfoot, Paspalum dilatatum, Huia white clover, Pitau white clover, Roa tall fescue, steer liveweight gains, seasonal herbage yields, herbage yields, herbage botanical composition.
Nine white clover (Trifolium repens L.) cultivars were established in a field trial near Hamilton to assess their adaptability to high fertility, intensively managed dairy pastures in the Waikato. The data presented are for the establishment phase of a three-year trial on Horotiu sandy loam in which cultivars will be evaluated for their persistence, competitiveness and Nt-fixing ability in the presence of perennial ryegrass (Lolium perenne L.) and application of N fertiliser. Three entries from New Zealand were “Grasslands Huia”, “Grasslands Pitau” and the Grasslands selection G18. Six cultivars from Europe were Aran, Blanca, Donna, Menna, Nesta and Sabeda. The cultivars represent a range of leaf sizes from medium-small to large. Aran and G18 (large leaved) generally developed stands with fewer thicker stolons than the other cultivars. Visual ratings of clover stand vigour during January to March 1983, . i.n.d.1,~a !e d that GiB had the greatest rate of estabiishment and ground cover despite its low stolon density. Perennial ryegrass seedling establishment was the least vigorous in G18 and Aran, and the most vigorous in Sabeda swards. Clover dry matter yields were generally highest for G18, Aran, Huia, Pitau and Donna, and lowest for Sabeda, Nesta and Menna. G18, Huia, Pitau, Eilanca and Donna maintained a higher clover content in the sward during the weedy establishment phase than the other cultivars. Keywords: Trifolium repens L., pasture establishment, white clover establishment.
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