Soil Amendment

Laboratory batch experiments were carried out to study the competitive sorption behavior of metals in three types of Indian soils, differing in their physicochemical properties: acid laterite (SL1), red alfisol (SL2) and black vertisol (SL3) treated with different proportions of ...

The persistence, mobility and degradation of tebuconazole were assessed under field conditions in a sandy clay loam soil amended with spent mushroom substrate (SMS) at two rates. The aim was to evaluate the environmental impact of the simultaneous application of SMS and fungicide in a vineyard soil. SMS is the pasteurized and composted organic material remaining after a crop of mushroom is produced. SMS is generated in increasing amounts in La Rioja region (Spain), and could be used as soil amendment in vineyard soils, where fungicides are also applied in large amounts. The study was carried out in 18 experimental plots (6 treatments and 3 replicates per treatment) over one year. Laboratory experiments were also conducted to verify the changes over time in the adsorption of fungicide by soils and in soil dehydrogenase activity caused by the fungicide and/or SMS. Tebuconazole dissipation followed biphasic kinetics with a rapid dissipation phase, followed by a slow dissipation phase. ...

Production and disposal of olive-mill wastes represent a problem of environmental relevance particularly in the Mediterranean countries where they are generated in huge quantities. A field trial was carried out to evaluate the short-term effects of soil amendment with solid olive mill waste (OMW) and its compost in comparison to the olive mill waste derived from the new two-phase treatment (humid OMW) and its resulting compost. The impact of treatments on soil water extractable organic matter and soil microbiota was determined. During a 120 days-long field trial, it was observed an initial increase of water extractable organic carbon (WEOC), total reducing sugars and total phenol compounds for all the amended soils. Even if humid OMW had the highest WEOC and total phenol compounds concentration, it increased to a lesser extent their content in the soil, probably due to the rapid utilisation of this particular organic matter by microorganisms. After three days from spreading, all amendments induced rapid modifications of both fungal and bacterial communities. However, while the bacterial community restored its initial state at the end of the trial, suggesting their high resilience capacity, the fungal populations changes remained until 120 days. The overall results indicated that all types of the organic materials tested as soil amendments had an impact on the soil microbial communities, especially in the early days of the field trial, without negative effects on the soil chemical characteristics.