SFF Project Summary
Nitrogen Interception and Uptake from Dairy Shed Wastes
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Quarterly Update: September 2005
Final Report [3.3M PDF]
Introduction
In the first trials under SFF Grant 01/058, two lines of ryegrass varieties were tested for nitrogen leaching. The experiment was carried out in small lysimeter pots in a glasshouse environment. The two varieties tested were identified as Ryegrass A and Ryegrass B. This first experiment showed that Ryegrass A was the best variety at limiting nitrogen leaching. This new trial called "Field lysimeter trial" has been established in the field to validate or otherwise the results obtained in earlier pot trials.
I - "Field Lysimeters Trial" description:
photo 1: Field lysimeters
The extension of SFF Grant Project 01/058 provided the funding for the construction of the 6, field plot-size lysimeters (10m2). Three varieties of perennial ryegrass were sown; the two varieties used in the original glasshouse trials identified as Ryegrass A, Ryegrass B and an additional variety identified as Ryegrass C
Each variety is replicated twice. The ryegrasses are now well established and the monitoring of the trials is underway.
The leachate from each of the six plots will continue to be collected over the coming months and analysed to measure the amount of nitrate intercepted by each of the treatments. Thus results will be obtained for a full year covering the periods winter, spring, summer and autumn (2003 – 2004) and a comparison with the results obtained from the glasshouse pot trials will be made.
II - Primary results
Following the complete establishment of the three ryegrasses, we have been refining the trial system and the monitoring of the leaching. This involves the application of the fertilizer input, testing the water input (rain simulation) and leachate collection. The first results obtained from analysis of the leachate collected is presented in the following table
Table1: Primarily results from analysis.
| Small Lysimeters trial in Glasshouse | Field lysimeter | |||
|---|---|---|---|---|
| Period | Winter conditions 2002 | Spring conditions 2002 | Summer conditions 2002 | From the 26/05 to the 02/07 2003 |
| Names | Relative leaching (% of Mean) | Relative leaching (% of Mean) | Relative leaching (% of Mean) | Relative leaching (% of Mean) |
|
Ryegrass A |
73 | 64 | 63 | 90.6 |
|
Ryegrass B |
116 | 132 | 149 | 110.3 |
| Mean (N leached) | 100 | 100 | 100 | 100 |
These initial trial results from the field lysimeters for the May / June period, showed that Ryegrass A was 19.7% better at limiting nitrogen leaching than Ryegrass B. This shows a correlation with our previous results obtained in the small lysimeters trial in the glasshouse.
Preliminary analysis of results for the July / September period suggest some variability with the earlier results from the May / June period. This may be a consequence of refining the management trials and the monitoring of the lysimeters.
Further analysis of the July / September results will be presented in the next quarterly report.
Quarterly Update: September 2005
The final part under this project, to identify grass seed
lines with superior nitrogen uptake, is reaching conclusion.
Final analysis of the glasshouse and field plots will now be undertaken, and a
full report of the findings will be made.
