scholarly journals Agronomic performance of RPR fertiIiser in a grazed pasture

1992 ◽  
pp. 41-44 ◽  
Author(s):  
S.D. Mcbride
Keyword(s):  
Phosphate Rock ◽  
Optimal Level ◽  
First Year ◽  
Agronomic Performance ◽  
Pasture Production ◽  
Olsen P ◽  
The Third ◽  
Initial Application ◽  
Grazed Pasture ◽  
Reactive Phosphate Rock

The effectiveness of Sechura RPR (SPR) plus sulphur (S) as a development and maintenance fertiliser was compared with superphosphate (SSP) on an irrigated grazed pasture. In 1980, SSP or SPR plus S was applied at 71 kg/ha phosphorus (P) to pastures that had not received fertiliser for 22 years, but had been recently over-drilled with ryegrass and white clover. Annual maintenance rates of 250 kg SSP/ha and 175 kg SPRjha plus S, (supplying 22 kg P/ha and 27 kg S/ha), were applied from 198 1 to 1992. In the first year the SSP treatment restored pasture production to near optimal level and this level was maintained over subsequent years with annual topdressings. In contrast, the SPR plus S treatment did not restore pasture production until the third year. In the first two years production from this treatment was only 69% and 88%. respectively, of the 250 kg/ha/year SSP treatment. From year 3, annual applications of SPR plus S maintained pasture production. In the first 3 years P concentrations of pasture topdressed with SPR were lower than those of pastures topdressed with SSP. Herbage S concentrations were adequate on both fertiliser treatments. Soil Olsen P levels rose quickly in the first year after the initial application of SSP then decreased to the same level as the SPR plus S treatment. Olsen P levels have been rising steadily since 1983, from both forms of P, indicating that 22 kg P/ha/year is above maintenance for this site. Keywords development fertiliser, irrigated pasture, maintenance fertiliser, Sechura reactive phosphate rock, superphosphate

scholarly journals Comparison of phosphate fertilisers in a grazed hill country pasture

1990 ◽  
pp. 97-100 ◽  
Author(s):  
A.D. Mackay
Keyword(s):  
Phosphate Rock ◽  
Slow Release ◽  
First Year ◽  
Pasture Production ◽  
Hill Country ◽  
Grazed Pasture ◽  
Reactive Phosphate Rock ◽  
Small Plot ◽  
Second Year

A grazing trial evaluated the agronomic effectiveness of 3 different types of phosphate (P) fertilisers. The same fertilisers were also evaluated in a small-plot mowing trial located within the grazing trial. In the grazing trial, which covered 35 ha of summer moist hill country, the partially acidulated phosphate rock (PAPR) and reactive phosphate rock (RPR) were as effective as superphosphate in stimulating legume and pasture production in the first year. In the second year the two slow-release materials continued to perform as well as SSP. In contrast in the mowing trial, superphosphate was more effective than RPR in the first year. This trial technique clearly underestimates the initial effectiveness of PAPR and RPR in grazed hill country. The traditional small-plot mowing trial technique, and the role of PAPR and RPR fertilisers in hill country, both need re-evaluation. Keywords hill country, superphosphate, slow release fertilisers, mowing trials, grazed pasture

A relation between wool production per animal and annual pasture dry matter production per animal

1982 ◽  
Vol 33 (4) ◽  
pp. 705 ◽  
Author(s):  
BA Rowe
Keyword(s):  
Dry Matter ◽  
Simple Relation ◽  
Dry Matter Production ◽  
First Year ◽  
Stocking Rate ◽  
Pasture Production ◽  
Wool Production ◽  
The Third ◽  
Matter Production ◽  
Curvilinear Relation

A simple relation between the annual wool production per animal (y) and the amount of pasture dry matter produced per animal (x) was derived and tested using the results from a grazing experiment in which the effects of superphosphate and stocking rate on wool and pasture dry matter production were measured from pastures which were continuously grazed by Merino wethers for 3 years. The linear relation, y = a + b/x, accounted for 63% of the variance in wool production per animal in the first year, 82 % in the second and 97 % in the third. Exclusion of an outlier from the first year results increased the variance accounted for to 85 %. This model is simpler and more precise than some others that have been published. It is also consistent with the curvilinear relation between production per animal (y) and pasture production per animal (x).

scholarly journals Response to re-application of phosphate fertilisers on hill pasture where fertiliser had been withheld for seven years

1993 ◽  
pp. 67-71
Author(s):  
S.F. Ledgard ◽  
G.J. Brier
Keyword(s):  
Phosphate Rock ◽  
Nitrogen Availability ◽  
Research Area ◽  
N Fixation ◽  
Single Superphosphate ◽  
Pasture Production ◽  
Hill Country ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock ◽  
P Rate

A field experiment at the AgResearch Te Kuiti Research Area examined effects of re-application of phosphorus (P) fertilisers on production and composition of hill pastures (1520% slope) which had received no P for 7 years. Treatments were 0, 20, 40 and 80 kg P/ha/year as single superphosphate (SSP) or North Carolina reactive phosphate rock (RPR). The soil was a yellowbrown earth/yellow-brown loam intergrade with Olsen P 9. Re-application of P produced a rapid and large increase in pasture production of up to 42 and 61% in years 1 and 2, respectively, and brought production up to 95% of that measured in neighbouring regularly fertilised paddocks. The pasture response to RPR was less (PcO.01) than that to SSP in both years, particularly at the highest rate. This indicated that RPR was less suitable for capital application. The P response was due almost entirely to an increase in white clover growth, and N, fixation was estimated to increase from 30 to 130 kg N/ha/year. In year 2, there was an increase in ryegrass content of pasture receiving the high P rate and this was attributed to increased nitrogen availability due to increased N, fixation. Keywords: hill country, phosphorus, reactive phosphate rock, superphosphate

The agronomic effectiveness of reactive phosphate rocks 3. A comparison of application strategies for soluble phosphorus and reactive phosphate rock fertilisers

1997 ◽  
Vol 37 (8) ◽  
pp. 947 ◽  
Author(s):  
D. L. Garden ◽  
G. N. Ward ◽  
P. W. G. Sale ◽  
S. Tennakoon ◽  
R. P. Hindell ◽  
...  
Keyword(s):  
North Carolina ◽  
Phosphate Rock ◽  
Dry Matter ◽  
Early Years ◽  
Triple Superphosphate ◽  
Pasture Production ◽  
Soil P ◽  
North Carolina Phosphate Rock ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock

Summary. An investigation into the effectiveness of large (up to 80 kg P/ha), single dressings (capital applications) of different phosphorus (P) fertilisers, compared with smaller annual applications, was undertaken in the National Reactive Phosphate Rock Project. Yield comparisons were made at 23 permanent pasture sites across Australia using triple superphosphate, the highly reactive North Carolina phosphate rock and a partially acidulated form of North Carolina rock. Over 4 years, 19 of 23 sites showed no significant reduction in mean annual pasture yield with a single, large dressing applied in year 1 only, compared with an equivalent amount of total P applied in 4 annual applications. At a site in North Queensland, where the initial soil P level was very low, the large year-1 application of each fertiliser resulted in increased pasture production over that obtained from smaller annual applications because of increased pasture production in the early years. This amounted to an annual increase of between 1500 and 3000 kg dry matter/ha for the capital application strategy. The effectiveness of capital applications depended on soil, pasture and climatic conditions, and on the type of P fertiliser. Soil and environmental factors which appear to be important in determining the effect of capital applications are whether soils allow leaching of P (a function of rainfall and texture), whether they are P-sorbing (a function of clay content and soil mineralogy), the soil P content and how quickly it is being utilised by the pasture. Capital applications can be considered where P is not leached from the soil profile or where P sorption is low, and are most effective where soil P is low and there is a responsive pasture species present. Capital applications of water-soluble P fertiliser should not be considered on free-draining, low P-absorbing soils. Average annual pasture dry matter losses of about 2000 kg/ha occurred with a capital application of triple superphosphate compared with annual applications, at one such site in Tasmania. North Carolina phosphate rock was found to be the most effective P fertiliser for large capital applications, especially on free-draining, low P-absorbing soils.

Development of sunny-facing high country using different forms of sulphur fertiliser

1990 ◽  
pp. 203-206
Author(s):  
M.D. Craighead ◽  
W.B. Burgess ◽  
S.A. Clark ◽  
R.G. Duffy
Keyword(s):  
Dry Matter ◽  
First Year ◽  
Available Nitrogen ◽  
Pasture Production ◽  
Hill Country ◽  
Nitrogen Levels ◽  
The Third ◽  
Soil Available Nitrogen ◽  
Sulphate Sulphur ◽  
Soluble Sulphate

Different forms and rates of sulphur (S) fertiliser were examined for developing oversown tussock in sunny-lying South Island high country. Sulphur significantly increased dry matter (DM) production (p = 0.0001). Soluble forms of S were most effective in the first year, and lasted 15-18 months. Sulphur bentonite prills took 6 months to be effective, but over time the higher rate (56 kg S/ha) was one of the better treatments. Elemental S on its own was ineffective even after 3 years. The combination of soluble sulphate and finely divided elemental S (56 kg S/ha as sulphur super extra) was the most effective treatment. In the first 2 years alsike clover was the most dominant pasture species. Native grasses became dominant in the third year. After retopdressing at the beginning of year 4, pasture production again improved, particularly in those treatments containing only soluble forms of S. White clover was the dominant pasture species in the fourth year. Sulphur significantly increased soil-available nitrogen levels (p = 0.0001). Keywords development, sunny hill country, sulphate sulphur, elemental sulphur, sulphur super extra, sulphur bentonite prills, available nitrogen

Soil sulfur status, sulfur fertiliser responses and rainfall sulfur accessions at trial sites in the National Reactive Phosphate Rock Project

1997 ◽  
Vol 37 (8) ◽  
pp. 995 ◽  
Author(s):  
G. Anderson ◽  
G. J. Blair ◽  
M. Crestani ◽  
D. Lewis
Keyword(s):  
Phosphate Rock ◽  
Direct Application ◽  
First Year ◽  
Soil Profiles ◽  
North West ◽  
The North ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock ◽  
Chemical Extractants ◽  
Soil Sulfur

Summary. The sulfur (S) status of the National Reactive Phosphate Rock Project trial sites was determined using 2 chemical extractants KCl-40 (0.25 mol KCl/L heated to 40°C) and MCP (0.01 mol mono-calcium phosphate/L). There were marked differences between sites in KCl-40- extractable S down the soil profile. Soil profiles were classified into 4 groups according to the shape of the extractable S profile. KCl-40 was better able to distinguish between responsive (significant at P = 0.10 only) and unresponsive sites than MCP. Mean S accession in rainfall over the 3 years ranged from 0.40 kg/ha . year at Jericho (site T17) in the centre of Tasmania to 20.33 kg/ha . year at Smithton (site T16) on the north-west coast of Tasmania. The proportion of S-responsive sites increased from 26% in the first year to 43, 42 and 48% in years 2, 3 and 4 respectively. Such a large proportion of S-responsive sites limits the use of direct application of reactive phosphate rock fertiliser.

EFFECTS OF NITROGEN FERTlLlSER ON PRODUCTION OF MILK SOLIDS FROM GRAZED PASTURE

1982 ◽  
pp. 58-63
Author(s):  
A.M. Bryant ◽  
K.A. Macdonald ◽  
D.G. Clayton
Keyword(s):  
First Year ◽  
Dairy Production ◽  
Pasture Production ◽  
Grazed Pasture ◽  
Second Year ◽  
Milk Solids ◽  
Production Response

In each of two years, eight 6.48 ha farmlets were used to assess effects of urea applications on dairy production. In the first year, 86 kg N/ha were applied in 2-3 dressings during May-August. Effects on annual milkfat and pasture production were not significant. In the second year 3-4 applications totalling 137 kg N/ha in April to September significantly increased annual milkfat and pasture production. Response in milkfat production per hectare to urea application averaged 0.22 (range - 0.16 to 0.45) and 0.25 (range - 0.1 I to 0.39) kgfat/ kgN in the first and second years respectively. These responses were not economic at present-day prices.

Changes in soil Olsen P over six years with annual applications of triple superphosphate or reactive phosphate rock (Sechura)

1994 ◽  
Vol 37 (2) ◽  
pp. 229-237 ◽  
Author(s):  
A. H. C. Roberts ◽  
A. G. Sinclair ◽  
P. D. Johnstone ◽  
W. H. Risk ◽  
L. C. Smith ◽  
...  
Keyword(s):  
Phosphate Rock ◽  
Triple Superphosphate ◽  
Olsen P ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock

scholarly journals Effects of reactive phosphate rock and superphosphate on sheep and pasture production in hill country

1991 ◽  
pp. 197-202
Author(s):  
S.F. Ledgard ◽  
K.R. Jones
Keyword(s):  
Phosphate Rock ◽  
Cost Effective ◽  
Research Area ◽  
Net Benefit ◽  
Single Superphosphate ◽  
Pasture Production ◽  
Hill Country ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock ◽  
A Site

Arad reactive phosphate rock (RPR) and single superphosphate(SSP) were compared as phosphate fertilisers in a sheep farmlet grazing trial and in two mowing trials over 3 years. The trials were on a volcanic ash soil at the MAF Te Kuiti Research Area on a site with limited fertiliser addition in the previous 2 years (Olsen P soil test averaged 10 in the grazing trial). Soil sulphur levels were high and there was no requirement for added sulphur over the -3 years of the trial. Pasture and animal measurements showed responses to SSP in all years, with RPR being initially less effective than SSP. By year 3, responses from RPR were near those from SSP. Economicassessmentof thegrazing trial corresponded with production data, except in year 1 when there was little benefit from either fertiliser. SSP was more cost-effective than RPR in year2 whereas they were similarin year 3. Over the 3 years, both fertilisers were profitable and there was an apparent cumulative net benefit from SSP over RPR. It was estimated that by year 4 the cumulative net benefit would be similar for both fertilisers or would be reversed in favour of RPR. Keywords reactive phosphate rock, hill country, grazing trial, superphosphate, mowing trials

LIME AND DAIRY PRODUCTION

1982 ◽  
pp. 93-103
Author(s):  
N.A. Thomson
Keyword(s):  
Soil Moisture ◽  
Dairy Cows ◽  
Milk Production ◽  
Soil Ph ◽  
Dairy Production ◽  
Pasture Production ◽  
The Third ◽  
One Year ◽  
Plasma Magnesium

In a four year grazing trial with dairy cows the application of 5000 kg lime/ ha (applied in two applications of 2500 kg/ha in winter of the first two years) significantly increased annual pasture production in two of the four years and dairy production in one year. In three of the four years lime significantly increased pasture growth over summer/autumn with concurrent increases in milk production. In the last year of the trial lime had little effect on pasture growth but a relatively large increase in milkfat production resulted. A higher incidence of grass staggers was recorded on the limed farmlets in spring for each of the four years. In the second spring immediately following the second application of lime significant depressions in both pasture and plasma magnesium levels were recorded. By the third spring differences in plasma magnesium levels were negligible but small depressions in herbage magnesium resulting from lime continued to the end of the trial. Lime significantly raised soil pH, Ca and Mg levels but had no effect on either soil K or P. As pH levels of the unlimed paddocks were low (5.2-5.4) in each autumn and soil moisture levels were increased by liming, these factors may suggest possible causes for the seasonality of the pasture response to lime

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