Towards the best practice for reusing lake sediments in agriculture and landscape engineering

The phosphorus may well be one of the most critical raw materials in the world as it is non-renewable and required for food production. Further, rock phosphates are also not evenly distributed across the Earth (85% in Morocco and Western Sahara!). Meanwhile the world phosphate fertilizer demand is constantly increasing. So, obviously there is a need for nutrients recycling in agriculture sector. Further, excessive fertilizer applications go beyond the crop demand leading to the P transfer into water bodies, causing their eutrophication. European countries produce about 200 million m³y⁻¹ of sediment removed from waterbodies which provides the potential of recycling nutrients from sediments in crop production. 

Doctoral student Mina Kiani in AgriChar research group is working on developing the best practice for reusing lake sediments in agriculture and landscape engineering in terms of agronomic performance as well as ecological sustainability. We have been comparing six different ways of applying sediments to soil, some of which include biochar treatments. We quantify nutrient availability in agricultural land as well as ryegrass biomass in a lysimeter experiment since Jan. 2017. Moreover, since June 2017, we are conducting a multi-year field experiment on the shore of the lake from where the sediments excavated. In the field experiment, we are testing the effect of treatments which had the best response in lysimeter experiment on ecological properties (heavy metal and organic contaminant uptake by plants, leaching of N and P, aggregate stability, soil biota and GHG emissions) in the real field condition.In October 2017, the lysimeter study was finished and all the soil and root samples collected for detailed analysis.

Field & lysimeter pics from Mina's project

We have obtained some really interesting results and soon we will share with you!