Crete Case Study experiments
1) Application of biological agents to increase crop resistance to salinityThe experiment tested the effectiveness of Trichoderma harzianum (a fungus) on tomato resistance to saline irrigation. This was a reference study (i.e. few samples but high stakeholder involvement) in order to provide reference for the experiment in a pilot study. The pilot study simulateed the experiment in a fully monitored greenhouse in TUC, Chania.
|Setting up the greenhouse experiment|
While T. harzianum successfully reduced the effect of higher salinity irrigation and positively affected bioavailable nutrients concentration in the soil, its effect was limited, especially on subsequent cropping seasons. Results showed that soil quality was significantly affected by the irrigation treatment, and production loss due to saline irrigation was substantial (21-38%), especially for the marketable fraction of yield. Also, from a point onward, the increased taste characteristics associated with higher salinity came at a high cost for both yield and soil health. Furthermore, 2nd year crops showed an even higher productivity risk even under improved irrigation water quality and soil salinity mitigation measures. Moreover, modelling results show that future conditions will worsen the situation for greenhouses that already face a high salinity problem, either by rendering production nonfeasible or by increasing water demand by as much as 25%.
2) Rainwater HarvestingThe Crete researchers also explored the cost-effectiveness of installing rainwater harvesting systems in greenhouses.
Regarding the cost-effectiveness of rainwater harvesting, high starting costs are a deterrent for its wider adaptation. Under saline irrigation, investing in a rainwater harvesting system rather than expanding the greenhouse cultivation area is more feasible since the increase in yield paid back is much faster. Some uncertainty remains regarding the feasibility of the system under subsequent dry hydrological years. Subsidizing the installation of rainwater harvesting systems can reduce these uncertainties and have a high added value for the local society and the level of provided ecosystem services.
Alexakis, D.D., Daliakopoulos, I.N., Panagea, I.S. and Tsanis, I.K., 2018. Assessing soil salinity using WorldView-2 multispectral images in Timpaki, Crete, Greece. Geocarto International, 33(4), pp.321-338. doi.org/10.1080/10106049.2016.1250826
I.N. Daliakopoulos, I.K. Tsanis, A. Koutroulis, N.N. Kourgialas, A.E. Varouchakis, G.P. Karatzas, C.J. Ritsema (2016) The threat of soil salinity: A European scale review. Science of the Total Environment http://dx.doi.org/10.1016/j.scitotenv.2016.08.177
Ioannis N. Daliakopoulos, Polixeni Pappa, Manolis G. Grillakis, Emmanouil A. Varouchakis, and Ioannis K. Tsanis (2016) Modelling soil salinity in greenhouse cultivations under a changing climate with SALTMED: Model modification and application in Timpaki, Crete. Soil Science 181(6), pp.241-251.
I. S. Panagea1, I. N. Daliakopoulos, I. K. Tsanis, and G. Schwilch (2015) Evaluation of soil salinity amelioration technologies in Timpaki, Crete: a participatory approach Solid Earth, 7, 177-190, DOI:10.5194/sed-7-2775-2015