DFG Trilateral collaboration Deutschland-Israel-Palestine: Irrigation with municipal effluents: effects on physical soil properties, contaminant transport, soil carbon dynamics, soil microbial activity and crop quality

点击翻译按钮获取中文摘要

Treated wastewater (TWW) is used since more than 45 years for irrigating crops in Israel. For sustainable agriculture and environmental conservation the input of organic matter, salts, nutrients and heavy metals with the TWW as well as the processes developing in the soil have to be considered and evaluated. In the first phase of this Trilateral project relevant information was gained about processes in irrigated soils concerning nutrient and heavy metal transport and plant uptake, soil hydrophobicity, soil aggregation, fungi, enzymes and microbial activity. It was shown with field and greenhouse experiments that the uptake of heavy metals into plants is less affected by TWW irrigation than by soil type. Soil microbial activity is enhanced by addition of TWW resulting in altered soil organic matter. In the first phase of the project the field experiment in Gaza was established and run for the duration of 2 years. Furthermore, the cooperation between all the partners was established in several meetings with scientific discussions. The second phase of the Trilateral project will consist of in-depth investigations and continuation of the field experiment. A well-established, unique lysimeter facility running since 2007 with the same setup can be used in the 2nd phase to study the development of hydrophobicity, infiltrability, soil aggregate formation and microbial parameters in soils with different clay content irrigated with four different water qualities. Additional lab experiments will be performed for the investigation of the effect of soil texture, vertical transport of nutrients and development of soil water repedency. The biological stability of organic matter will be studied with priming effect experiments, enzyme profiling and in situ visualization with special focus on the hydrophobic soil surface and deeper soil horizons. The integrative analysis of the results will provide new insights into the interactions between element fluxes, SOM turnover, biological activity and surface hydrophobicity in TWW irrigated soils.