THE RESULTS of cutting trials which have been designed to provide information on grazing frequency and intensity in pasture rotations have, in both temperate and tropical regions, often shown that lax and infrequent cutting promotes higher dry matter production than does more intensive and frequent cutting, except on prostrate rhizolmatous and stoloniferous pastures These results have, however, seldom been successfully translated into increased animal production where the negative association frequently observed between dry matter production and both herbage quality and the degree of utilization of the dry matter produced often negates the increased production resulting from lax and infrequent grazing. Added to this are the longer term effects of spelling interval and grazing intensity on sward density and botanical composition, these effects varying through the season as the morphological condition of the pasture species changes.
The seasonal and annual production of New Zealand perennial ryegrasses were compared with that of a number of overseas cultivars. Several imported tetraploids established much more quickly than the New Zealand standards. R.V.P. Melle, Barlatra, S23 and New Zealand Mangere showed good summer drought resistance. At Waimate Mangere gave the h,ighest seasonal and total production while at Timaru, where Mangere was not included, Grasslands Ruanui and Grasslands Ariki gave the highest autumn, spring and total yields. White clover was usually higher yielding when with the less productive ryegrasses. This often meanst that ryegrass plus clover yield differences were less than those of the ryegrass cultivars alone.
The results of three annual ryegrass cultivar trials showed that, of seven cultivars, the Dutch tetraploid Western Wolths Tewera Barenza established first and made good autumn growth. Three tetraploid Western Wolths cultivars including Grasslands Tama were observed to give the best early spring growth. In contrast, the two later maturing Dutch tetraploid Italian ryegrasses gave the highest late spring and early summer production, Poor maximum total yields, the tetraploid Western Wolths ryegrass Billion was the most consistent cultivar. In addition, the tetraploids, whether Italian or Western Wolths, tended to be more productive than the New Zealand diploid Grasslands Paroa (Ralian) or Gramlands Manawa (short-rotation) ryegrasses.
T HE EARLY SETTLERS and their stock moved into the inland South Island tussock grasslands in the 1850s. It was an area of rich pasture and the official estimate of the time (1857) was that the superior grasses could carry one sheep to two acres, good grasses one sheep to three acres, and inferior one sheep to four to five acres (Beettie, 1947).
Pot experiments have shown that browntop is more efficient in utilizing scarce phosphate than is white clover when white clover is obtaining nitrogen either from fixation or from the soil. There is evidence that browntop can reduce the amount of phosphate available to clover both by direct competition and by decreasing the soil moisture and hence ,the availability of phosphate. These effects are probably not peculiar to (browntop which, however, does have a mat that can effectively shade clover stolons thereby reducing #the activity of clover stolon nodes and the ability of clover to regrow leaf. Reduced phosphate availability and stolon shading exert a powerful control on clover growth and this control is likely to be strongly expressed on set-stocked hill country, particularly if the soil has a high P fixing capacity and easily dries out.
A PROPERTY of 484.2 ha at Broladlands South, 22 km north-east of Taupo, was purchased in July 1964. The soils of the farm are derived directly from the Taupo ash shower, and there are four clearly defined areas on the property.
In two experiments carried out at Massey University it was shown that ‘Massey Basyn’ Yorkshire fog gave similar dry matter yields to Ruanui, Ariki, and Manawa ryegrasses and promoated lamb liveweight gains similar to those ,obtained on Ruanui ryegrass pastures. Lamb birthweights were significantly lower on Yorkshire fog than on ryegrass pastures. Yorkshire fog was relatively slow to establish, but low grass production in the early stages was balanced by increased clover growth. The seasonal production of Yorkshire fog was well distribumted. Yorkshire fog suppressed white clover and volunter species more than did the ryegrasses, particularly in spring, when Yorkshire fog plots gave lower yields than ryegrass plots.
Two pot experiments compared the yield response and uptake of N and P by five New Zealand, two exotic ecotypes and one bred cultivar of Yorkshire fog and Ruanui perennial ryegrass under varying levels of applied N and P. One experiment was conducted in a heated glasshouse and the other under controlled climate conditions. Of the Yorkshire fog strains examined, the bred cultivar 'Massey Basyn’ and an ecotype from Rotorua provided highest yields of dry matter. Their superiority was attributed in part to their ability to extract greater amounts of N and P from the soil. The former was more efficient under high levels of applied N and the latter under high levels of applied P. Under two distinct climatic environments, ‘Massey Basyn’ Yorkshire fog gave similar yields and uptake of N and P to Ruanui perennial ryegrass. Under a third climate, with higher temperatures and moisture stress, ‘Massey Basyn’ outyielded Ruanui. This was associated with a greater ability by ‘Massey Basyn’ to utilize absorbed P.
MY PROPERTY consists of 301 ha of hill country, one-third steep, two-thirds medium, shed 18 km west of Piopio in the rain shadow of the Pomerangi Ranges, with an annual rainfall of about 2540 mm. It is all in grass except 16 ha of rocks and patches of scenic bush, and is well fenced with 22 main paddocks anfd 8 small holding paddocks. All paddocks have adequate natural water and access to the farm is very good because of county roads radiating from the woolshed. This is a very real advantage in one-man farming oif hill country. The longest drive for a mob of ewes and lambs would usually be less than one hour, depending on variables such as dog behaviour.
Farming patterns of the Te Kuiti district. are described. Progress is reviewed, and comments are made on significant trends and problems.
The challenge to management in producing milk, meat and wool profitably from pasture is briefly described and the role of various management manipulations of feed and stock in meeting this challenge is discussed. Feed budgeting is helpful in the making of decisions about some of these manipulations. The construction of a management feed budget is described, two examples are given of its use, and the implications of possible inaccuracies in the data used in feed budgeting are discussed.
Parent materials such as volcanic ash and sedimentary siltstone and sandstone form soils which differ markedly in their physical and chemical properties. In stocking x fertilizer rate trials on two families of soils, Te Kuiti-Tumutumu (volcanic ash) and Mahoenui-Mangatea (siltstonesandstone) , the former showed marked response to increasing rates of superphosphate in terms of pasture availability and animal production but -the latter showed negligible response above :the lowest rate (250 kg/ha). Responses to superphosphate were apparent on Te Kuiti-Tumutumu only at the high stocking rate. Sward composition showed no measurable improvement with the application of superphosphate. Manage ment practices were undoubtedly important in this respect. Differential ‘topdressing should be practised where feasible. When soil test levels for phosphate are medium to low, Te Kuiti-Tumutumu soils should receive at least 500 kg/ha/yr of superphosphate, Mahoenui-Mangatea soils 250 kg/ha/yr. Stocking rates and management practices must be such as to allow full utilization of the additional pasture grown.
Field experiments conducted on soils derived from Mairoa ash beds showed that they respond markedly to phosphate and require heavy phosphate applications for the maintenance of high pasture production. Thus, on Dunmore and Otorohanga silt loam annual rates of 375 and 750 kg/ha of superphosphate were needed for maintenance of 85 and 95% of maximum production, respectively. After cessation of phosphate dressings, the decline in pasture production was dramatic, even on plots with high initial dressings. In cases where soil test values for potassium were below 10, moderate and statistically significant potash responses were measured. Small annual applications of carbonate of lime (312 kg/ha) gave a slight but statistically non-significant increase in production (3%). However, heavier applications (625 and 1250 kg/ha) significantly decreased production on Dunmore silt loam, at pH of 5.8, after the sixth and seventh annual applications.
THE FARM, situated 56 km south of Te Kuiti, is of 300 ha of which 285 ha are in grass. There are 33 paddocks mostly watered by natural streams. Good access to the farm is by a county road which runs 2.5 km through the centre of the property.
Grazing experiments at Armidale have shown variable reiponses in sheep production to fodder conservation. (1) Responses to conservation vary with stocking rate. At low stocking levels, responses are very small. At very high stocking levels, conservation practice may result in a lower production. The greatest response occurs at an intermediate stocking rate. (2) Results depend on rainfall. (3) Wool production may be increased by conservation but reproduction and growth are much less respoilsive in the Armidale environment. These findings can be explained by a simple energy flow model. The model provides additional insights on factors such as the timing of feeding, Ihe importance of hay quality and the relatively low potential of fodder conservation for increasing meat, production.
Yorkshire fog (Holcus lanatus L. var. ‘Massey Basyn’) pastures were grazed almost continuously by sheep at high stocking rates for five years. The surviving tiller or paddock population was compared with the original seed population, and with the nine original parents of the variety, by growing the populations as widely-spaced plants and measuring plant size, erectness, leaf size, leaf strength, and heading date. In general, there was a slight genetic shift in the paddock populatmion towards {the mean of the parents and away from the mean of the seed population. Differences in the frequencies of esterase isoenzyme bands between the seed and paddock populations provided further evidence that a genetic shift had occurred. However, the magnitude of the shift was small, particularly by comparison with the range of variation observed wit,hin each population and between the parents. ‘Massey Basyn’ is therefore considered to possess an acceptable degree of genet,ic stability under continuous grazing.
Aftermath recovery of ‘Massey Basyn’ Yorkshire fog (Holcus lanatus L.) following seed production and the retention of this species as a dominant within the sward can be aohieved without the need for post seed harvest cultivation or cutting. However, where a late seed crop has been taken, nitrogen should be applied to the area to encourage the rapid recovery of ‘Massey Basyn’ Yorkshire fog at the expense of other grasses which may be present.
Pasture on north aspects of steep hill country (Waingaro steepland soil) produced more dry matter than on south aspects (7100 kg/ha cf. 6400 kg/ha) owing predominantly to a significantly higher growth rate during winter and early spring. Pasture species composition differed between aspects and changed during the year, especially on north aspects where Paspafum dilatatum and pasture dead matter content varied inversely with the amount of legumes and other grasses. A highly significant negative relationship Ibetween land slope and production accounted for 22% of the variability in pasture growth rate on both north and south aspects over the major part of the year excluding late autumn and winter. Soil moisture and grass temperature differed with aspect and also in their individual effect on pasture growth during the year. Temperature level and difference between aspects was found to be affected to a large extent by cloud cover, especially during winter on the south aspect (warmer than in clear weather) and during summer on the north aspect (cooler than in clear weather).
IHUMATAO FARMS comprised a town supply farm at Mangers (No. 2 farm) until six years ago, when a sheep farm situated 32 km away at Karaka was purchased (No. 1 Farm).
The liveweight gain of young sheep set-stocked on browntop and ‘Grasslands Ruanui’ perennial ryegrass pastures was compared during the main periods of pasture growth over two years. During spring there was no difference between the two species, but in early summer, although flowering was suppressed by grazing, the higher liveweight gains on ryegrass were attributed to greater stem and stolen development and poorer leaf growth in the browntop pasture. In early autumn an outbreak of staggers in the ryegrass sheep apparently reduced liveweight gain relative to browntop where no staggers occurred. These differences are discussed in relation to the closer grazing of ryegrass than browntop at this time of year.
TUSSOCK GRASSLAND SOILS contain abundant coarse and fine VA endophytes. Rhizophagus tenuis is more prominent in high-altitude soils. This species is an effkieat symbiont with ‘a variety of grasses but only under extreme phosphate deficiency; otherwise this endophyte may depress growth, probably by competing with its host for phosphorus.
BEFORE discussing grassland, it would probably be useful to put Unheld Kingdom agriculture into perspective, and compare total land and its utilization with New Zealand figures.
The operator of an economic unit of North Island pastoral land describes some of his current practices in order to define areas in which progress is being made, as well as areas where he meets distinct problems. Some thought is given to directions where management and more importantly thinking may be able to move in future.
The evidence available on pasture production in the King Country is reviewed and compared with stock requirements. A potential carrying capacity of 19 stock units/ha in the Waitomo County is estimated. It is shown that, when product prices are high, the economic optimum stocking rate is near the point beyond which stock will be seriously underfed. Management techniques aimed at producing and utilizing pasture feed efficiently and also allowing flexibility in stocking rates to meet varying economic conditions are outlined.
The case for feed budgeting on intensively stocked farms is briefly discussed, and a summary is given of the information required to draw up a meaningful feed budget. Therefore, after describing the procedure followed at Ruakura, particular attention is given to the problems and pitfalls in accurately assessing pasture cover, both before and after grazing. Photographs are used to illustrate many of the situations encountered in the day-to-day use of the pasture assessment technique.
Forty-five lines of 11 species of Poa were introduced and grown as spaced plants in winter and spring plantings at four locations. Visual assessment was made of growth habit, relative vigour and inciidence of disease. Establishment of P. trivialis, P. palustris and P. nemoralis was good, but subsequently all Pea lines were markedly inferior to the controls, being either small or prostrate or very erect and stemmy. Many lines were very suscept,ible to Puccinia poae-nemoralis Otth., a rust which is frequent among local populations of P. pratensis. It was concluded that introduced Poa species arc unlikely to Ibe of agricultural importance in New Zealand although P. pratensis may be valuable in areas of dry summers and cold winters such as the Mackenzie Country. It is suggested that further trials be carried out in this area including local ecotypes of P. pratensis.
The paper discusses the components of feed budgeting. The main possibilities which can be considered as useful alternatives to equate feed supplies with stock requirements are described. Comments are also made about the interaction of stock with pasture production, the quantitative approach to feed budgeting, and the use of a clear objective to avoid confusion when discussing the application of the technique.
CUTTING TRIALS designed to simulate lucerne defoliation by grazing animals were conducted in stands of irrigated Wairau lucerne over two seasons.
The occurrence and distribution of soil moisture deficit days in the Waikato were determined for 43 years (1930-73) by calculating day-to-day changes in soil moisture for four soil types. The calculations were based on actual daily rainfall data and an estimate of mean daily potential evapotranspiration. Seasonal distributions of the number of deficit-days are given. On three soil types with 87, 102 and 117 mm of available soil moisture there were more than 20 such days in at least 15 of the 43 years. January to April inclusive are the “high-risk months”. A significant negative correlation was obtained between the number of deficit-days and pasture production from a non-irrigated, “rate-of-growth” trial, such that 20 deficit-days gave a 21% reduction in expected annual pasture production (below that expected with no deficit-days).
The soil pattern of the King Country is dominated by soils developed on volcanic ash. The ash mantle is made ump of three broad groups: old ashes (Kauroa Ash and Hamilton Ash); middle age ashes (Rotoehu Ash, Oruanui Ash and Mairoa Ash) and young ash (Taupe Pumice). In the western part of the district the most extensive soils are yellow-brown loams formed on Mairoa Ash; in the eastern part, yellow-brown pumice soils on Taupo Pumice. It is only where erosion has partly or completely removed the ashes from the steeper slopes of the hill country that soils (mainly yellowbrown earths) can form on the underlying greywacke, sandstones and mudstones. Recent soils from alluvium, in association with swamps and peat bogs occur in the valleys of streams and rivers. Although the underlying rocks do not contribute extensively to the soils of the district, ‘they do give rise to characteristic landscapes - e.g., greywacke gives steep, narrow valleys and ridges: mudstones give hummocky, slumped slopes; limestones give bluffs, isolated towers, dry valleys and tomos and sandstones and ignimbrites give prominent bluffs.
A VISITOR to New Zealand gains the impression that the farmers have developed a highly successful integration of grassland and livestock, obtaining high outputs of animal products for the minimum of inputs - the ultimate in low cost production.
A METHOD was developed in which plant material was fractionated by a successive extraction technique for calcium and magnesium.
THE USE of commercially coated or pelleted grass seed may improve establishment of oversown grasses. In this study, the effects of seed treatment on ballistics and on the physical and chemical environment during germination were examined.
A WARD of white clover was defoliated by sheep at two grazing pressures (high and low), each over three grazing durations (3, 6 and 9 days) on three occasions during the summer period af 1972-3.
Results are presented from a survey of the frequency of occurrence of pasture species in the different topographical and soil type areas of the Manawatu. It was carried out in the early spring of 1967 and again in the summer of 1968. The survey indicated a high frequency of occurrence of browntop on hill country (81 and 87% in early spring and summer, respectively) and terrace country (46 and 40%, respectively) and moderate amounts on flat land and sand country. Lowest occurrence was recorded on flat country dairy farms (15 and 17%, respectively). Marked differences in species frequency of occurrence were recorded between farms on hill country. These ranged from farms in which pastures were dominantly browntop, sweet vernal, and moss, to farms where relatively high amounts of white clover, ryegrass, and dogstail occurred in association with other less productive species. These differences have been related to produotivity levels possible from such extremes in species composition. Results are discussed in relation to current hill country farming practices. Factors considered to be significant in altering hill country botanical composition and hence levels of productivity are also discussed.
Results from trials at Te Kuiti in 1971 and 1972 substantiated for the better fertility Mairoa Ash soils the results obtained from nitrogen trials elsewhere in New Zealand. High responses (24 to 39 kg DM/kg N for applications of 2.5 kg N/ha) were obtained from early spring applications. Substantial carry-over responses (up to 65% of total response) were measured for applications made in the cold winter months of 1972. Evidence from overseas and New Zealand is reviewed which suggested higher residual responses to applied nitrogen in grazing trials than in mown plot trials. An economic analysis based on the Te Kuiti trial results investigates the profitability of hay versus nitrogen, and optimum rates of nitrogen application for two cattle fattening policies. Some practical aspects of using nitrogen on King Country farms are considered.
Browntop invasion into hill country sown to ryegrass-white clover showed rapid vegetative spread over 2 years followed by dense tiller development. Initially a distribution mosaic formed, ryegrass and clover being positively associated with each other, but negatively associated with browntop. Subsequently, ‘browntop spread into the ryegrass-clover microsites. Browntop ingressed under close, continuous grazing but not under lax, rotational grazing. Competitive interactions of clover and 'Grasslands Ruanui’ and ‘Grasslands Manawa’ ryegrasses ,involved were partitioned. Browntop was markedly suppressed by interspecific shading under infrequent cutting, but survived to spread into spaces provided by nonpersistent ryegrass. Management to modify competition for light to control browntop is considered.
YORKSHIRE FOG probably has its origin in the Iberian Peninsula (Vinal and Hein, 1937) but, as a result of continued colonization since the end of the ice age, is now found throughout Europe from the limiits of northern Scandinavia and Iceland to the Caucasus Mountains and North West Africa (Beddows, 1961; Hulten, 1950; Bother and Larsen, 1958). Under the influence of human pastoral activities, the species has spread to all of the more recently developed farming areas in the temperate regions of the Americas, South Africa and Australasia.
RAPID ESTABLISHMENT and aggressive spread of plants, normally regarded as weed qualities in lowland pastures, are desirable qualities for pioneering eroded mountain slopes.
Seed production by ‘Massey Basyn’ Yorkshire fog (Holcus lanatus L.) was greatest (mean 323 kg/ha) with early closing (June 30), but lodging occurred on these plots and commercial harvesting would be difftcult. With later closing (July 31 and August 31), lodging did not occur and average yields of about 250 kg/ha were obtained. Very late closing (September 30) resulted in a severe yield depression. Application of nitrogen fertilizer either at closing or at inflorescence initiation increased seed yields by an average of 30%. Peak seed yields occurred later at harvest time as closing was delayed. With the optim8um combination of treatments, yields of 400 kg/ha were achieved and it is suggested that yields of at least 200 kg/ha could be obtained commercially.
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