Year of study:
pre-1987
Lead organisation & Collaborators:
Department of Agriculture and Rural Affairds
Contact:
Dairy Research Institute, Ellinbank
Best available science assessment:
Overall Score: 27
Overall rating: High
|
Objectives |
Conceptual model |
Study design |
Soil analysis |
Production & financial |
Method reporting |
Data analysis |
Results reporting |
Publication |
|
4 |
4 |
3 |
3 |
2 |
3 |
2 |
3 |
3 |
Project details
Objectives:
Results from about 600 trials investigating the effects of N fertiliser on Victorian pastures over the past 50 years have been collected and reviewed. The review sought to quantify the magnitude of pasture responses to fertiliser and interactions with various management treatments.
Hypotheses:
The review considers a variety of effects of N fertilizers. In relation to soil pH, the hypothesis under consideration was that nitrogen fertilizers have affect on soil acidity.
Basis of trial:
Nitrogen fertilisers have an effect on soil acidity.
Location details:
Trial site details:
Over 600 trials, occurring over the 50 years prior to publication (in 1987) were compiled to inform this review.
Pre-trial management:
Not specified
Trial management:
Not specified
Reportage:
How results have been reported:
Technical Report
Research Report series No 54, December 1987
How a copy of any relevant reports can be obtained:
DPI Knowledge Resource Centre
Level of review of results:
Internal technical review
Results:
Summary of key findings of trial:
Athough there is nearly always increased growth with increased N fertilizer, the magnitude of responses and the interactions with various management treatments have been variable.
Average growth responses are 10kg DM/kg N. Marginal Reponses and average responses decline as the rate of N decreases.
Variation in soil pH with time and management influence:
One set of trials investigated the effect of six N fertilizers (applied at 112 kg N / ha / year for four years in an unspecified location.
|
Fertilizer |
pH (0 -75 mm) |
pH (75 – 150 mm) |
|
Control |
7.4 |
8 |
|
Sodium Nitrate |
7.6 |
8.1 |
|
Potassium Nitrate |
7.4 |
8 |
|
Calcium ammonium nitrate |
7.3 |
8 |
|
Nitrophoska red |
7 |
7.8 |
|
Urea |
6.9 |
7.9 |
|
Ammonium Sulphate |
6.4 |
7.7 |
The results confirmed other findings ammonium sulphate is the only commonly used fertilizer likely to significantly increase soil acidity
Variation in productivity/ profitability with time & management influence:
Average growth responses were 10kg DM / kg N and the proportion of clover in pasture falls.
Experimental Design:
Treatments:
Various treatments
Trial design/layout:
Distribution of Nitrogen trials (1932-1985)
| East Gippsland | 33 |
| Central Gippsland | 27 |
| West Gippsland | 69 |
| South Gippsland | 49 |
| Central | 48 |
| Central Highlands | 45 |
| South West | 50 |
| Western District | 42 |
| Goulburn Valley | 128 |
| North East | 51 |
| TOTAL | 550 |
Soil Sampling:
Not specified
pH tests were reviewed.
Plant and/or animal production measurements:
Average growth responses by pasture were reviewed (DM /kg N applied). Clover cover also reviewed as a function of N application (kg N/ha), and the effects on N fertilization in spring on seed yields for perennial grasses.
Cost and value of production:
|
Fertilizer |
Cost ($/tonne) |
|
Urea |
304 |
|
Foliar Spray |
419 |
|
Ammonium Sulphate |
264 |
|
Ammonium Nitrate |
335 |
|
Calcium Ammonium Nitrate |
220 |
|
Sodium Nitrate |
537 |