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

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 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

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

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

Long-term changes in soil fertility and pasture production under no, low and high phosphorus fertiliser inputs

2011 ◽  
pp. 37-42 ◽  
Author(s):  
A.D. Mackay ◽  
M.G. Lambert
Keyword(s):  
Soil Fertility ◽  
Published Data ◽  
Research Station ◽  
Pasture Production ◽  
Ongoing Research ◽  
Hill Country ◽  
Fertiliser Application ◽  
Farm Business ◽  
Stocking Rates

Many hill country farmers have struggled to maintain fertiliser inputs in recent years. The long-term fertiliser and sheep grazing farmlet study at the AgResearch Ballantrae Hill Country Research Station provides invaluable insights into the benefits of continued annual inputs of phosphorus (P) fertiliser on production levels and the farm business, and also the implications to the production system when fertiliser is withheld. Since detailed monitoring stopped in 1990, the fertiliser treatments have been maintained, along with nominal sheep stocking rates and grazing practices. Occasional measurements of soil fertility have also been made on the farmlets that have received either no fertiliser inputs for 30 years, a low annual fertiliser input (125 kg superphosphate (SSP)/ha/yr), or a high input (375 kg SSP/ha/yr) for 35 years. In this paper changes in sheep stocking rate and soil fertility are reported and compared with earlier published data from this longterm site. This field study provides a valuable resource for ongoing research into nutrient requirements and cycling in hill land environments, and a visual demonstration of the continued importance of fertiliser application as a driver of hill country production. Keywords: Livestock production, P fertiliser, Olsen P, long-term sites

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.

Phosphorus fertilizer for nitrogen fertilized dairy pastures. 1. Long term effects on pasture, diet and soil

1997 ◽  
Vol 129 (2) ◽  
pp. 205-217 ◽  
Author(s):  
T. M. DAVISON ◽  
W. N. ORR ◽  
B. A. SILVER ◽  
R. G. WALKER ◽  
F. DUNCALFE
Keyword(s):  
N Fertilizer ◽  
Panicum Maximum ◽  
Phosphorus Fertilizer ◽  
Long Term Effects ◽  
Single Superphosphate ◽  
Soil P ◽  
P Fertilizer ◽  
Autumn And Winter ◽  
Extractable Soil

The phosphorus fertilizer requirements and long term productivity of nitrogen-fertilized Gatton panic (Panicum maximum cv. Gatton) pastures, grazed by lactating dairy cows, were evaluated over 7 years. Cows grazed at 2·6 cows/ha on pastures that received annually 100 or 300 kg N/ha at each of 0, 22·5 or 45 kg P/ha. Phosphorus treatments were applied as single superphosphate, balanced for calcium by applications of gypsum.The soil had an initial available soil phosphorus content of 40 mg/kg (bicarbonate extraction). At zero P fertilizer (0P), extractable soil P declined at the rate of 1·9 mg/kg each year; at 22·5P it was maintained close to the original level while at 45P it increased at 6·6 mg/kg each year. Increased P fertilizer caused significant (P<0·01) increases in plant P concentration from year 2 onwards. In years 6 and 7 there was significantly less green pasture and leaf on offer in 300N pastures at 0P than with 22·5P and 45P. There was no influence of rate of P fertilizer at 100N on pasture quantity on offer in any year. There were clear trends at 100N of decreasing total pasture and green dry matter (DM) on offer over the 7 years, but not at 300N.Cows at 300N consumed more leaf in the diet in autumn and winter than at 100N. Leaf was 55–60% of the diet in summer and autumn, but decreased to 21% (100N) and 37% (300N) in winter. Dead material in the diet was always higher at 100N. Pasture leaf percentage and leaf yield were the best individual predictors of leaf percentage in the diet. Diet P selected from pasture was reduced by the higher rate of N fertilizer in each season. Estimated P concentrations of the diet selected from pasture for summer, autumn and winter averaged 0·30, 0·38 and 0·28% DM for 100N and 0·19, 0·24 and 0·18% DM for 300N treatments, respectively.The response to P fertilizer was dependent on the rate of N fertilizer applied. The critical bicarbonate extractable soil P level for this soil type, below which pasture responses occurred, was 30 mg/kg at 300N. The critical level at 100N was not reached, but was <23 mg/kg P.

scholarly journals Phosphorus Speciation in Long-Term Drained and Rewetted Peatlands of Northern Germany

Soil Systems ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 11
Author(s):  
Wakene Negassa ◽  
Dirk Michalik ◽  
Wantana Klysubun ◽  
Peter Leinweber
Keyword(s):  
Total Concentration ◽  
Long Term Effects ◽  
P Fractions ◽  
Edge Structure ◽  
Soil P ◽  
Wet Chemical ◽  
Labile P ◽  
X Ray Absorption ◽  
Total P

Previous studies, conducted at the inception of rewetting degraded peatlands, reported that rewetting increased phosphorus (P) mobilization but long-term effects of rewetting on the soil P status are unknown. The objectives of this study were to (i) characterize P in the surface and subsurface horizons of long-term drained and rewetted percolation mires, forest, and coastal peatlands and (ii) examine the influence of drainage and rewetting on P speciation and distributions using wet-chemical and advanced spectroscopic analyses. The total P was significantly (p < 0.05) different at the surface horizons. The total concentration of P ranged from 1022 to 2320 mg kg−1 in the surface horizons and decreased by a factor of two to five to the deepest horizons. Results of the chemical, solution 31P nuclear magnetic resonance (NMR), and P K-edge X-ray absorption near-edge structure (XANES) indicated that the major proportions of total P were organic P (Po). In the same peatland types, the relative proportions of Po and stable P fractions were lower in the drained than in the rewetted peatland. The results indicate that long-term rewetting not only locks P in organic matter but also transforms labile P to stable P fractions at the surface horizons of the different peatland types.

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