Long term effects of withholding phosphate application on North Island hill country: Whatawhata Research Centre

1990 ◽  
pp. 11-16
Author(s):  
A. G.Gillingham S. Richardson ◽  
I.L. Power ◽  
J. Riley
Keyword(s):  
Large Scale ◽  
Soil Depth ◽  
Residual Effects ◽  
Research Centre ◽  
Total Production ◽  
Long Term Effects ◽  
Pasture Production ◽  
Hill Country ◽  
Olsen P ◽  
Fertiliser Application

From June 1984 to May 1988 a large-scale grazing trial at Whatawhata Research Centre evaluated the effects of a halt to previous superphosphate fertiliser application on hill country production. Over the 4-years pasture production, pasture species composition, stock grazing days or Olsen P soil fertility status were little affected as a result of halting topdressing. Pasture production declined most on 'easy' ( lo-20° slope) slopes after a halt to fertiliser application. The decline was greatest (lo- 13 %) where previous rates of fertiliser had been high. Total production on 'steep' (30~40° slope) slopes did not decline significantly. However, at soil test (Olsen P) levels of less than 10 the pasture moss and dead matter content increased, indicating a deterioration in pasture quality. Legume content did not decline. Within the range of normal topdressing rates to hill country (O-30 kg P/ha/yr) Olsen P tests did not reflect topdressing differences or any effects of a halt to fertiliser application. At higher topdressing rates (50-100 kg Plhalyr) the effect of continued or discontinued topdressing was reflected predominantly in the O-3 cm soil depth. A halt to previous topdressing significantly reduced available grazing over the final 3 years. This decline reflected the decline in measured pasture production. Keywords Phosphate, fertiliser, hill country, residual effects

scholarly journals Precise aerial fertiliser application on hill country

1999 ◽  
pp. 221-226
Author(s):  
A.G. Gillingham ◽  
J. Maber ◽  
J. Morton ◽  
M. Tuohy
Keyword(s):  
Application Rate ◽  
Economic Returns ◽  
Related Factors ◽  
Pasture Production ◽  
Economic Return ◽  
Soil P ◽  
Topographic Complexity ◽  
Hill Country ◽  
Olsen P ◽  
Fertiliser Application

The fertiliser requirements of hill country vary with soil type, slope and aspect-related factors which govern pasture production potential and species composition. In most situations, the topographic complexity is such that only very broad differentiation in land units can be made when aerially applying fertiliser. The traditional method of aerial topdressing is for superphosphate to be flown on at a common rate over large blocks of complex topography by fixed-wing aircraft. Advances in geographical positioning system (GPS) and aircraft technology now allow aircraft to fly accurately defined track spacing and so achieve optimum uniformity of fertiliser spread. The same technology could be used to vary fertiliser application rate along a flight path according to predetermined recommendations and through links to a farm geographic information system (GIS) map. This approach could also be used to apply different fertiliser types. In a desktop study the effects of differential, compared with uniform, fertiliser application policies, on animal productivity and economic returns were examined for three contrasting hill farm situations using a combination of trial results and the AgResearch PKS Lime Programme. Results showed that for a farm with a low soil P status (Olsen P =9), that stocking rate could be increased by 0.5 su/ha, and the economic return by 7.5%, by differential, rather than uniform fertiliser application. In a similar but higher soil P status farm (Olsen P = 15), the increase was 0.9 su/ ha and 10.1% respectively. In a summer-dry situation where nitrogen fertiliser could be substituted for some P fertiliser, a differential policy designed to optimise production gave a 2.1 su/ha and 43% net margin increase, compared with the uniform application of a typical rate of maintenance P fertiliser only. The results from the desktop study are discussed in relation to the practical aspects of developing differential fertiliser application methods. This will relate to extra fertiliser application cost, and the definition of practical sized land units and fertiliser forms, which will all have some effect on the net economics of a differential application policy. Despite these unknowns, the technology would appear to offer real gains to the hill country farmer. Keywords: economic return, fertiliser application, GIS, GPS, hill country, phosphate

Long term effects of withholding phosphate application on North Island hill country: Economics

1990 ◽  
pp. 29-33
Author(s):  
D.A. Clark ◽  
S.F. Ledgard ◽  
M.G. Lambert ◽  
M.B. O'Connor ◽  
A.G. Gillingham
Keyword(s):  
Cash Flows ◽  
Cost Ratio ◽  
Long Term Effects ◽  
Pasture Production ◽  
Soil P ◽  
Hill Country ◽  
Fertiliser Application ◽  
Positive Cash Flow ◽  
Sustainable Productivity

Results from fertiliser cessation experiments at Ballantrae, Te Kuiti and Whatawhata, on yellow-brown earths, were used to evaluate the fertiliser cessation compared to continued application on hill country breeding ewe systems. At Balhmtrae, on farmlets previously receiving 125 kg superphosphate/ha/yr, continued fertiliser application generated a positive cash flow after 8 years. On farmIets previously receiving rates of 200-375 kg superphosphate/ha/yr positive cash flows were generated by continued fertiliser application after 4, 5 and 6 years at Te Kuiti, Whatawhata and Ballantrae respectively. Fertiliser cessation is a sound strategy to survive periods of low product price:fertiIiser cost ratio. However, it will decrease sustainable productivity and hence farm resale value. Fertiliser recommendations cannot remain constant over time but must consider: animal enterprise, product and fertiliser price, soil P status, and level of pasture utilisation. Keywords fertiliser cessation, superphosphate, Olsen P, economics, hill country, pasture production

scholarly journals Long term (?) effects of withholding superphosphate application on North Island hill country: a 10-year update

1999 ◽  
pp. 63-68 ◽  
Author(s):  
M.B. Dodd ◽  
S.F. Ledgard
Keyword(s):  
Species Composition ◽  
White Clover ◽  
Low Fertility ◽  
Botanical Composition ◽  
Long Term Effects ◽  
Pasture Production ◽  
Hill Country ◽  
Olsen P ◽  
Over Time

Measurements of soil phosphate, pasture production and botanical composition from two superphosphate fertiliser trials in northern North Island hill country (Whatawhata and Te Kuiti) have been made over a 15-year period. The impacts of superphosphate fertiliser withholding have included a decline in Olsen P, decreases in annual pasture production of 10-17% (Whatawhata) and 22-42% (Te Kuiti), decreases in the abundance of productive and desirable species (15-20% for ryegrass and white clover), and increases in the abundance of undesirable species (browntop and other low fertility grasses). These changes have increased over time, beyond that period covered by the original experiments (4-6 years). Different responses to withholding between the two sites are still apparent, and the reasons for these are explored. It is not clear that these systems have yet reached a new equilibrium, nor how long it will take for this to happen. The implications for our view of longterm grassland studies are discussed. Keywords: fertiliser, long-term, pasture production, pasture species composition

scholarly journals Effects of withholding fertiliser on pasture production and phosphate cycling in hill country

1990 ◽  
pp. 17-20
Author(s):  
J.S. Rowarth ◽  
A.G. Gillingham
Keyword(s):  
P Uptake ◽  
Available P ◽  
Research Centre ◽  
Pasture Production ◽  
Inorganic P ◽  
Hill Country ◽  
Olsen P ◽  
Plant P Uptake ◽  
Dung Decomposition ◽  
Plant Available P

A large-scale phosphate (P) fertiliser grazing trial was carried out at Whatawhata Research Centre between 1980 and 1984. The effect of 5 fertiliser rates (10, 20 30, 50 or 100 kg P/ha) on pasture production, plant P uptake, dung P distribution, dung decomposition and Olsen P concentration were monitored on 4 slope groups (campsites, O-10"; easy, 1 I-20"; moderate, 21-30" and steep, 31" +). Soils collected from each slope and fertiliser treatment were used in a pot trial to investigate the size of the plant available P pool. Results can be used to interpret data from field trials where fertiliser has been withheld. Initially, pasture production or Olsen P will change little because the most productive areas of the paddock receive large amounts of dung P which buffer the effect of fertiliser withdrawal. On these areas P is cycled more rapidly than on steep slopes, further buffering the system against P deficiency. Small changes in Olsen P do not reflect the more rapid changes in inorganic P or plant-available P. As inorganic P becomes depleted, plant P uptake decreases. The associated decrease in dung P return and the slower rate of dung decomposition contribute to a slowing of the P cycle. The net effect is less feed and slower regrowth after grazing. Recovering from this state will require not only P fertiliser but also time for high producing pasture species to regenerate. Keywords phosphate cycling, topdressing, fertiliser, pasture production, hill country, dung

scholarly journals Long term effects of withholding phosphate application on North Island hill country: Te Kuiti

1990 ◽  
pp. 21-24 ◽  
Author(s):  
M.B. O'Connor ◽  
C.E. Smart ◽  
S.F. Ledgard
Keyword(s):  
Research Area ◽  
Dominant Factor ◽  
Soil Test ◽  
Stocking Rate ◽  
Long Term Effects ◽  
Pasture Production ◽  
Hill Country ◽  
Olsen P ◽  
Noticeable Increase

A farmlet grazing trial at the Te Kuiti Research Area (20 km south of Te Kuiti) began in April 1983 to study the effects on production of reducing or withholding fertiliser over a 6-year period. The effects of withholding fertiliser are considered in this paper. The soils on which the trial was conducted are Mahoenui or Mangatea silt loams typical of 1.3 million ha of North Island hill country. Applications of 250 kg/ha/annum of superphosphate had been applied for 10 years before the trial began, leading to Olsen P tests of 14. In spite of moderate soil test levels, declines in both animal and pasture production where fertiliser was withheld were evident from year 2. By years 3-4 onwards, production declines of some 20-30% were evident. Effects on pasture composition where fertiliser was withheld were evident, with less white clover and more moss and weeds. No noticeable increase in scrub weeds or brush weeds occurred. Maintaining a high stocking rate (or stock pressure) was considered a dominant factor in this regard. Keywords grazing trial, fertiliser, hill country, phosphate, animal production, pasture production

scholarly journals Modelling hill country pasture production: a decision tree approach

2004 ◽  
pp. 195-201
Author(s):  
B.S. Zhang ◽  
I. Valentine ◽  
P.D. Kemp
Keyword(s):  
Decision Tree ◽  
Summer Drought ◽  
Pasture Management ◽  
Pasture Production ◽  
Hill Country ◽  
The North ◽  
Hill Slope ◽  
Tree Models ◽  
Fertiliser Application ◽  
Autumn And Winter

Decision tree models were applied to predict annual and seasonal pasture production and investigate the interactions between pasture production and environmental and management factors in the North Island hill country. The results showed that spring rainfall was the most important factor influencing annual pasture production, while hill slope was the most important factor influencing spring and winter production. Summer and autumn rainfall were the most important factors influencing summer and autumn production respectively. The decision tree models for annual, spring, summer, autumn and winter pasture production correctly predicted 82%, 71%, 90%, 88% and 90 % of cases in the model validation. By integrating with a geographic information system (GIS), the outputs of these decision tree models can be used as a tool for pasture management in assessing the impacts of alternative phosphorus fertiliser application strategies, or potential climate change, such as summer drought on hill pasture production. This can assist farmers in making decisions such as setting stocking rate and assessing feed supply. Keywords: data mining, decision tree, GIS, hill slope, rainfall

Resident hill country pasture production in response to temperature and soil moisture over 20 years in Central Hawke’s Bay

2021 ◽  
Vol 17 ◽  
Author(s):  
Annamaria Mills ◽  
Beverley Thomson ◽  
Paul Muir ◽  
Noel Smith ◽  
Derrick Moot
Keyword(s):  
Growth Rates ◽  
Climate Data ◽  
Pasture Production ◽  
Hill Country ◽  
Use Efficiency ◽  
Climate Station ◽  
Fertiliser Application ◽  
Highly Correlated ◽  
Response To Temperature ◽  
Water Holding

The production of resident pastures on rolling hill country was measured in three paddocks over 20 years at Poukawa in Central Hawke’s Bay. The pastures had been routinely fertilised with 250 kg/ha/yr of superphosphate but no pasture renovation, nor nitrogen fertiliser application, occurred during the measurement period. Total annual dry matter (DM) yield ranged from 4.5 to 12.8 t/ha/yr, which shows the level of variability to be expected in this summer-dry environment. The greatest proportion (60-90%) of growth occurred in winter/spring with consistent mean growth rates of 50-62 kg DM/ha/d in September and October. These rates were calculated to be 5.49±0.55 kg DM/ha/°Cd when spring moisture was non-limiting. The pastures had a mean water use efficiency of 16.9±0.34 kg DM/ha/mm of water available (R2 = 0.93). The amount of water available was calculated from a soil water budget based on a plant available water holding capacity of 124 mm (0-1.0 m depth). The results provide coefficients that can be combined with readily available climate data to predict pasture growth rates for feed budgeting purposes. Rainfall data collected on-site was highly correlated (r=0.94) with that predicted from the NIWA virtual climate station network.

scholarly journals SOIL FERTILITY AND HILL COUNTRY PRODUCTION

1982 ◽  
pp. 153-160 ◽  
Author(s):  
M.G. Lambert ◽  
P.C. Luscombe ◽  
D.A. Clark
Keyword(s):  
Summer Rainfall ◽  
Research Area ◽  
Grazing Management ◽  
Low Fertility ◽  
N Availability ◽  
Stocking Rate ◽  
Pasture Production ◽  
Hill Country ◽  
Olsen P ◽  
Legume Growth

Soil, pasture and animal responses to 2 levels of superphosphate were measured within a farmlet trial, at Ballantrae hill country research area, near Woodville, during 1975-80. Soil and pasture measurements were also made for 3 years before the trial started. Pastures, which were dominated by low-fertility-tolerant grasses (LFTC;), moss and flatweeds, were oversown with 4 legumes before the trial started. Soil Olsen P level was 5 under untopdressed pasture in 1973, and 9 in 1975 after application of 500 kg/ ha superphosphate. Superphosphate rates were 120 (on low fertiliser areas q LF) and 640 (on high fertiliser areas = HF) kg/ ha/ yr average during 1975/80. Annual pasture production (adjusted for variable summer rainfall) was 7.1 t DM/ ha from untopdressed pasture and 8.1 t following 500 kg superphosphate/ ha in 1973-74. LF production rose to 8.5, and HF to 12.0, in 1980. Legume contribution rose from 5% in untopdressed pasture to 18% and 23% in LF and HF respectively in 1975/76. By 1979/80 legume contribution had steadily declined to 10% on both treatments, probably due to a measured increase in soil N availability and increased competitiveness of associated grasses. Ryegrass content rose at both fertiliser levels, while LFTG content fell; these trends were greatest under HF. Winter stocking rate was increased from 6 to 10.9 and 14.9 su/ha on LF and HF-respectively. Per animal performance did not decrease. A range of techniques which could increase efficiency of superphosphate use in hill country is discussed. These techniques include: selective application to responsive pastures; spring application; grazing management to encourage legume growth.

scholarly journals Long term effects of withholding phosphate application on North Island hill country: Ballantrae

1990 ◽  
pp. 25-28 ◽  
Author(s):  
M.G. Lambert ◽  
D.A. Clark ◽  
A.D. Mackay
Keyword(s):  
Residual Activity ◽  
Annual Rainfall ◽  
Research Station ◽  
Long Term Effects ◽  
Pasture Production ◽  
Hill Country ◽  
Phosphate Retention ◽  
Reactive Phosphate Rock ◽  
Average Annual Rainfall

In a farmlet grazing trial at DSIR's Ballantrae Hill Country Research Station near Woodville the effect of withholding phosphate application was investigated. Soils are yellow-brown earths and related steepland soils with low phosphate retention, and average annual rainfall is 1200 mm. Four 10 ha farmlets, 2 each with histories of high (HF) or low (LF) superphosphate application, had annual applications continued at 125 (LF-LF) or 375 (HFHF) kg/ha; or discontinued on one farmlet in each case (LF-NF and HF-NF), starting in 1981. Soil Olsen P level decreased on the HF-NF area, but not on LF-NF and pasture production decreased by 4.6 and 1.7% p.a. respectively. Botanical composition was affected only on the HF-NF farmlet. Ewes were lighter as a result of not applying fertiliser. Ewe and lamb wool production, and lamb liveweight, were reduced by an average 1.2, 3.7 and 2.6% p.a., respectively, over the 7 years. A phosphate application trial suggested that reactive phosphate rock was as effective as superphosphate in stimulating legume responses in the 1st year after restarting phosphate application, and had greater residual activity. Keywords fertiliser, withholding, cessation, phosphate, superphosphate, hill country, pastures, soil fertility, wool, sheep

The role of differential fertiliser application in sustainable management of hill pastures

2003 ◽  
pp. 253-257
Author(s):  
A.G. Gillingham ◽  
J.D. Morton ◽  
M.H. Gray
Keyword(s):  
Management Plan ◽  
Economic Benefits ◽  
Environmental Benefits ◽  
High Rate ◽  
Yield Potential ◽  
High Yield ◽  
Pasture Production ◽  
Hill Country ◽  
Wide Range ◽  
Fertiliser Application

New targets for increased productivity from the sheep and beef industry are about 4% annually, at a time of ever heightening environmental awareness. A major part of this will occur by applying current technology to increase the productivity from the presently lowerthan- average farms. However leading farmers will also have to increase efficiency or productivity if they are to remain economically viable. One prospect is to examine the natural variability in hill pastures and determine if this can be more appropriately managed to improve economic returns. Hill farms have soil and topographic var iability, which can result in a wide range in pasture production. Yet a uniform rate of fertiliser is usually applied to such land. This results in under prescription of fertiliser for high yield potential zones, and similarly over prescription for low yielding zones. The conversion of easier hill land to dairying has shown how pasture productivity can be improved by applying higher rates of fertiliser and utilising the extra pasture efficiently. This approach could be applied within parts of hill farms. The main fertiliser used on hill farms is superphosphate which supplies phosphorus (P) and sulphur (S) for legume growth. This assumes that there is enough clover present to make it worthwhile. However most hill pastures, especially on steep slopes, are low in clover and as a result most are predominantly nitrogen (N) deficient for a large part of the year. The pasture responses to P and S are therefore limited by low soil N levels and N fertilisers give a better economic return. The application of a high rate of N fertiliser to hill country could more than double pasture production. The technology is almost ready to allow accurate, differential application of fertiliser to hill farms from fixed wing aircraft. This should further improve economic benefits. A differential fertiliser management plan has environmental benefits through improved soil stability and associated water quality from hill catchments. Keywords: differential fertiliser application, hill country, hill country variability

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