Alfalfa crops amended with MSW compost can compensate the effect of salty water irrigation depending on the soil texture.

The availability of water resources of marginal quality such as drainage water or high-saltcontaining groundwater is turning into an important issue in Tunisia and other countrieswith scarce water resources. A pot experiment was carried out to evaluate plant produc-tion, nutrient content and heavy metal bioaccumulation in agricultural soils amended withMSW compost and irrigated with salty water, by using two different soil textures (clay andsandy). Salt water supply decreased plant dry yield in both soils. Salt stress had signifi-cantly reduction in plant biomass in sandy soil compared to those in clay soil (biomass ofdry weight is significantly higher in clay soil than those in sandy soil in presence of salt:percentage of growth compared to control was 55% for clay soil and 45% for sandy soil).The application of Municipal Solid Wastes (MSW) Compost increased significantly alfalfaproductivity in both soils (Dry weight is significantly higher in presence of compost: 140%for clay soil and 125% for sandy soil). In non-amended soil, the growth was reduced signifi-cantly by salt stress (50% in clay soil, 26% in sandy compared to the soils without salty waterapplication). Plants irrigated with salty water accumulated much more sodium on sandysoil (1.74 mmol g−1) than on clay one (0.87 mmol g−1DW). Compost did not reduce sodiumaccumulation in aerial parts on sandy soil, whereas it slightly reduced it in those grownon clay soil. Zinc (Zn), Copper (Cu), Lead (Pb) and Cadmium (Cd) concentrations showedthe same trend for both soil types. They increased statistically significant by salinity to124-189%, the highest rise was found in Cu concentration on clay soil. The order of metaluptake was: Zn > Cu > Pb > Cd. A higher significant shoot accumulation of heavy metals (upto 305% of the control) was noticed in the presence of compost with no difference betweensalt-treated and non-treated. MSW compost amendment caused an increase of the studiedheavy metals in alfalfa shoots grown that was higher on sandy soils than clay soils. Heavymetals in plants remained lower than phytotoxic level and these level of accumulation did not restrain the enhancement of alfalfa yield. MSW compost at 40 t ha−1was convinent todo not attend phytotoxic level. These results suggest that MSW compost compensates, atleast partially, the negative effect of salinity on plant growth and nutrient uptake and thatit is important to know soil texture to apply compost to remediate salty degraded soils.© 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved