The effect of situational variability in climate and soil, choice of animal type and N fertilisation level on nitrogen leaching from pastoral farming systems around Lake Taupo, New Zealand
Agricultural systems with grazing animals are increasingly under scrutiny for their contribution to quality degradation of waterways and water bodies. Soil type, climate, animal type and nitrogen (N) fertilisation are contributors to the variation in N that is leached through the soil profile into ground and surface water. It is difficult to explore the effect of these factors using experimentation only and modelling is proposed as an alternative. An agro-ecosystem model, EcoMod, was used to quantify the pastoral ecosystem responses to situational variability in climate and soil, choice of animal type and N fertilisation level within the Lake Taupo region of New Zealand. Factorial combinations of soil type (Oruanui and Waipahihi), climate (low, moderate and high rainfall), animal type (sheep, beef and dairy) and N fertilisation level (0 or 60Â kgÂ N/ha/yr) were simulated. High rainfall climates also had colder temperatures, grew less pasture and carried fewer animals overall which lead to less dung and urinary N returned. Therefore, even though a higher proportion of N returned ultimately leached at the higher rainfall sites, the total N leached did not differ greatly between sites. Weather variation between years had a marked influence on N leaching within a site, due to the timing and magnitude of rainfall events. In this region, for these two highly permeable soil types, N applied as fertiliser had a high propensity to leach, either after being taken up by plants, grazed and returned to the soil as dung and urine, or due to direct flow through the soil profile. Soil type had a considerable effect on N leaching risk, the timing of N leaching and mean pasture production. Nitrogen leaching was greatest from beef cattle, followed by dairy and sheep with the level of leaching related to urine deposition patterns for each animal type and due to the amount of N returned to the soil as excreta. Simulation results indicate that sheep farming systems with limited fertiliser N inputs will reduce N leaching from farms in the Lake Taupo catchment.
If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.
As the access to this document is restricted, you may want to look for a different version under "Related research" (further below) or search for a different version of it.
References listed on IDEAS
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
- Berntsen, J. & Petersen, B. M. & Jacobsen, B. H. & Olesen, J. E. & Hutchings, N. J., 2003. "Evaluating nitrogen taxation scenarios using the dynamic whole farm simulation model FASSET," Agricultural Systems, Elsevier, vol. 76(3), pages 817-839, June.
When requesting a correction, please mention this item's handle: RePEc:eee:agisys:v:104:y:2011:i:3:p:271-280. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Dana Niculescu)
If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.
If references are entirely missing, you can add them using this form.
If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.
If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.
Please note that corrections may take a couple of weeks to filter through the various RePEc services.