Rice growth, yield and water productivity responses to irrigation scheduling prior to the delayed application of continuous flooding in south-east Australia
The majority of rice grown in south-east Australia is continuously flooded for much of its growing season, but reduced irrigation water availability brought about by a combination of drought and environmental flow legislation has presented a need to maintain (or even increase) rice production with less irrigation water. Delaying the application of continuous flooding until prior to panicle initiation can increase input water productivity by reducing non-beneficial evaporation losses from free water and the soil. A field experiment was conducted over two growing seasons, 2008/9 and 2009/10, comparing a conventional dry seeded treatment (the control - continuous flooding from the 3 leaf stage) with delayed continuous flooding (10-20 days prior to panicle initiation) with several irrigation scheduling treatments prior to flooding commencement. In the first year, the delayed water treatments were irrigated at intervals of 40, 80 and 160Â mm of cumulative reference evapotranspiration (ETo) prior to delayed continuous flooding, thereby imposing differing degrees of crop water stress. In year 2, the 80 and 160Â mm treatments were modified by use of a crop factor (Kc) when the plants were small and the 40Â mm treatment was replaced with a continuously flooded treatment throughout the crop duration. Decreases in net water input (irrigationÂ +Â rainÂ -Â surface drainage) and increases in input water productivity were achieved by reducing the flush irrigation frequency during the pre-flood period. Savings of 150 and 230Â mm (10 and 15%) were achieved in Year 1 from the 80 and 160Â mm cumulative ETo irrigation frequency treatments, respectively, in comparison to the control. In the second year, net water input savings of 230 and 330Â mm (15 and 22%) were achieved with the 80/Kc and 160/KcÂ mm treatments, respectively. Input water productivity of the 160Â mm treatment was 0.06Â kg/m3 (8%) higher than the control in Year 1, while in Year 2 a 0.15Â kg/m3 (17%) increase in input water productivity above the control was achieved by the 160/KcÂ mm treatment. Delaying the application of continuous flooding in the second year greatly extended the period of crop growth suggesting the need for earlier sowing (by 7-10 days) to ensure pollen microspore still occurs at the best time to minimise yield loss due to cold damage. Nitrogen fertiliser management is an important issue when delaying continuous flooding, and nitrogen losses appeared to increase with the frequency of irrigation prior to continuous flooding. This was likely due to increased denitrification from alternate wetting and drying of the soil. Further research is required to determine the most appropriate nitrogen management strategies, and to also better define the optimal pre-flood irrigation frequency.
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.:
- n.d., 2010. "Libri ricevuti," STUDI ECONOMICI, FrancoAngeli Editore, vol. 2010(101), pages 123-123.
- Editors, 2010. "Marlat Prices for Seminars," Journal of Political Economy, University of Chicago Press, vol. 118(4), pages 1-1, 08.
- Bouman, B. A. M. & Tuong, T. P., 2001. "Field water management to save water and increase its productivity in irrigated lowland rice," Agricultural Water Management, Elsevier, vol. 49(1), pages 11-30, July.
When requesting a correction, please mention this item's handle: RePEc:eee:agiwat:v:98:y:2011:i:12:p:1799-1807. 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.