Irrigation of Castor Bean (Ricinus communis L.) and Sunflower (Helianthus annus L.) Plant Species with Municipal Wastewater Effluent: Impacts on Soil Properties and Seed Yield

Water

Michalis K. Chatzakis¹  Vasileios A. Tzanakakis¹  Duncan D. Mara² 

[1] Institute of Iraklion, National Agricultural Research Foundation (N.AG.RE.F.), Iraklion 71307, Greece; E-Mails:;Department of Civil Engineering, University of Leeds, Leeds LS2 9JT, UK; E-Mail:

关键词: wastewater reuse;    land application;    bioenergy crops;   

DOI  :  10.3390/w3041112

来源: mdpi

【 摘 要 】

The effects of plant species (castor bean (Ricinus communis L.) versus sunflower(Helianthus annus L.)) and irrigation regime (freshwater versus secondary treated municipal wastewater) on soil properties and on seed and biodiesel yield were studied in a three year pot trial. Plant species were irrigated at rates according to their water requirements with either freshwater or wastewater effluent. Pots irrigated with freshwater received commercial fertilizer, containing N, P, and K, applied at the beginning of each irrigation period. The results obtained in this study showed that irrigation with effluent did not result in significant changes in soil pH, soil organic matter (SOM), total kjeldahl nitrogen (TKN), and dehydrogenase activity, whereas soil available P was found to increase in the upper soil layer. Soil salinity varied slightly throughout the experiment in effluent irrigated pots but no change was detected at the end of the experiment compared to the initial value, suggesting sufficient salt leaching. Pots irrigated with effluent had higher soil salinity, P, and dehydrogenase activity but lower SOM and TKN than freshwater irrigated pots. Sunflower showed greater SOM and TKN values than castor bean suggesting differences between plant species in the microorganisms carrying out C and N mineralization in the soil. Plant species irrigated with freshwater achieved higher seed yield compared to those irrigated with effluent probably reflecting the lower level of soil salinity in freshwater irrigated pots. Castor bean achieved greater seed yield than sunflower. Biodiesel production followed the pattern of seed yield. The findings of this study suggest that wastewater effluent can constitute an important source of irrigation water and nutrients for bioenergy crop cultivations with minor adverse impacts on soil properties and seed yield. Plant species play an important role with regard to the changes in soil properties and to the related factors of seed and biodiesel yields.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.