Winchmore long-term fertiliser trial

Objective
To establish the response of pasture (ryegrass and white clover) production (kg ha-1 yr-1) and productivity (production per unit of phosphorus input) to increasing rates of phosphorus (P) fertiliser applied as single superphosphate (SSP) or reactive phosphate rock (RPR)
Description
As the longest fertiliser trial under pasture in New Zealand, the Canterbury Plains site has been providing useful information for more than 70 years now. Focused on sheep-grazed pasture, it was initially established to analyse the long-term response of pasture to irrigation and the superphosphate requirements of irrigated pasture. However, the consistent management, meticulous record-keeping and archiving of regular soil and plant samples have also proved a rich source of material for many other studies, from nutrient cycling to the effects of fertiliser use on earthworms.
Data Access Statement
Available online with registration
Data Access Notes
https://figshare.com/articles/dataset/Winchmore_long-term_Fertiliser_and_Irrigation_trial_data/12456494?file=25110983
Data license
CC BY-NC
Data URL
https://doi.org/10.6084/m9.figshare.12456494
Data policy
https://figshare.com/articles/dataset/Winchmore_long-term_Fertiliser_and_Irrigation_trial_data/12456494?file=25110983
Organization
AgResearch
research organisation
Person
Prof Dr Rich McDowell
principal investigator

Site: Winchmore long-term fertiliser trial

Type
research farm
Location
Winchmore
Canterbury
New Zealand
Geographic location
-43.786865, 171.795101
© OpenStreetMap contributors
Elevation
160 Metres
Slope
Visits permitted?
Yes
Visiting arrangements
Contact winchmore@agresearch.co.nz
History
The Winchmore field trials represent some of New Zealand’s longest running scientific experiments and, globally, the longest running trials of grazed and irrigated pasture. Since their establishment over 70 years ago, data from the trials have been used in nearly 500 publications (Cousins & McDowell 2012). However, as shown by Rickard & Moss (2012), this is only a partial measure of the trials’ value. More poignant measures include recognition of the role Winchmore played in establishing dairying in Canterbury, the importance of phosphorus (P) and sulphur (S) to soil fertility, and the establishment and management of irrigation systems that underpin much of the rural economy in Canterbury.
Soil type
cambisol
Soil description
The soil is a Lismore stony silt loam classified as an Orthic Brown soil in the New Zealand soil classification and as an Udic Ustochrept in USDA soil classification.
Soil properties
VariableDepthValue (range)UnitsRef yearEstimated?Baseline?
soil organic carbon0 – 7.5 Centimetres2.7 Percent1952
plant available phosphorous0 – 7.5 Centimetres7 parts per million1952
soil pH 6.1 (5.7 – 5.9) 1952
Climatic type
temperate oceanic climate
Climate properties
VariableTime periodValue (range)Units
air temperature12 degree Celsius
precipitation745 (419 – 949) millimeter

Design period: Trial 1 (1952—1958)

Design Type
Randomized complete block design
Description
This area was ploughed in winter 1948 out of a browntop (Agrostis spp.) pasture. After summer fallowing it was bordered and greenfeed sown in autumn 1949. The area was ploughed and again summer-fallowed before being sown to pasture (Perennial ryegrass; Short rotation ryegrass; Timothy; Crested Dogstail; White clover; Subterranean clover; Red clover) in February 1950. Lime at 2.5 t/ha and 125 kg/ha superphosphate were applied with the greenfeed and a further 2.5 t/ha lime and 250 kg/ha superphosphate at sowing down. When the trial was commenced, the 2-year old pasture was perennial ryegrass (Lolium spp.) and white clover (Trifolium repens) dominant. During the trial, the treatments that received superphosphate remained predominantly ryegrass and white clover dominant.
Design description
The fertiliser trial has 20 border check irrigation bays divided into five treatments each with four replicates set out in a randomised block design.
Number of plots
20
Number of subplots
5
Number of replicates
4
Number of harvests per year
9
Crops
CropYears grown
rye grass
white clover
Factor
Factor name
Factor levels
superphosphate exposure
Five P-fertilization levels
P0  (0 kg/ha)
1952—1962
P1  (188 t/ha)
1952—1964
Application frequency: 1
autumn application
P2  (376 kg/ha)
1952—1962
Application frequency: 1
autumn application
P3  (564 kg/ha)
1952—1961
Application frequency: 1
autumn application
P4  (376 kg/ha)
1952—1958
Application frequency: 2
split application between autumn and spring
Measurements
VariableMaterialUnitsFrequencyScaleComment
plant biomassAll crops1pasture production was measured using exclusion cages (3.25 x 0.61 m), with two cages per plot
soil organic carbonSoil1A composite soil sample of 10 cores (2.5 cm diameter) was collected from each plot to a depth of 7.5 cm. These were initially collected at 3-month intervals (July, October, January and April) but in the later years were collected either at 6-month intervals or annually (July) prior to fertiliser application (1948-1952)

Design period: Trial 2 (1958—1980)

Design Type
Randomized complete block design
Description
These treatments ran from 1958/59 to 1979/80. Pasture production data were therefore available from areas receiving no superphosphate, 188 kg/ha and 376 kg/ha for 28 years, and the residual effects of 376 kg/ha and 564 kg/ha over 21 years.
Design description
The fertiliser trial has 20 border check irrigation bays divided into five treatments each with four replicates set out in a randomised block design.
Number of plots
20
Number of subplots
5
Number of replicates
4
Number of harvests per year
9
Crops
CropYears grown
rye grass
white clover
Factor
Factor name
Factor levels
superphosphate exposure
Five P-fertilization levels
P0  (0 kg/ha)
1959—1979
P1  (188 kg/ha)
1959—1979
Application frequency: 1
autumn application
P2  (0 kg/ha)
1959—1979
residual P-levels from trial 1 (376 kg/ha), autumn application
P3  (0 kg/ha)
1959—1979
residual P-levels from trial 1 (564 kg/ha), autumn application
P4  (376 kg/ha)
1959—1979
Application frequency: 1
P4 applied in two plots from the original treatments (P2 and P4) from Trial 1, cumulative effect

Design period: Trail 3 (1980—)

Design Type
Randomized complete block design
Description
In 1980 it was decided to introduce two new treatments: 250 kg/ha superphosphate and Sechura phosphate rock + gypsum (equivalent to 250 kg/ha superphosphate).
Number of plots
20
Number of subplots
5
Number of replicates
4
Number of harvests per year
9
Crops
CropYears grown
rye grass
white clover
Factor
Factor name
Factor levels
superphosphate exposure
Five P-fertilization levels
P0  (0 kg/ha)
1980—
P1  (188 kg/ha)
1980—
Application frequency: 1
superphosphate
P2  (250 kg/ha)
1980—
Application frequency: 1
superphosphate
P3  (250 kg/ha)
1980—
Application frequency: 1
Sechura phosphate rock + gypsum (equivalent to 250 kg/ha superphosphate)
P4  (376 kg/ha)
1980—
Application frequency: 1
superphosphate
Measurements
VariableMaterialUnitsFrequencyScaleComment
soil total carbonSoil
total soil nitrogenSoil
total soil phosphorousSoil
plant available phosphorousSoil
potassium contentSoil
sulphur contentSoil
soil organic matterSoil
cadmiumSoil
fluorineSoil
earthwormSoil
yieldAll cropsmonthlyMonthly mean dry matter yield for each treatment 1980-2019 and annual dry matter yield for each plot from 1994-2019 (n=494)
botanical compositionAll cropsannuallySeasonal or annual botanical composition and yield from 1952-2019 (n=3351) and from each plot and cut from 2005-2019 (n=2944)

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