Sewage sludge use in bioenergy production. A case study of its effects on soil properties under Cynara cardunculus L. cultivation

Abstract

Energy crops cultivation is expected to further increase, which represents an opportunity to establish synergies able to enhance key environmental components (i.e. soil). To reach this benefits crop management is crucial and should be properly assessed. The aim of this work is to provide an insight on the effects of sewage sludge compost (SSC) on soil properties, when this material is applied as basal dressing for the cultivation of a Mediterranean energy crop (Cynara cardunculus L.). A 3-years trial (2008/2011) was conducted in Alicante (Southeastern Spain), testing four SSC application rates (0, 30, 50 and 70 t/ha) on a heavy textured Anthrosol. The addition of SSC enhanced soil fertility, primarily increasing organic carbon (Cox), Kjeldahl nitrogen (Nk), available P (PBurriel), CuDTPA and ZnDTPA levels. Comparatively with the control (0 t/ha), 30, 50 and 70 t/ha treatments induced a rise of 11%, 19% and 25% in Nk (Control=1.11 g/kg) and PBurriel (Control=79 mg/kg), while for Cox (Control=11.8 g/kg) was 14%, 21% and 30%. However, these variables apparently did not significantly decrease throughout the experiment, which suggests that the organic matter added was under a stabilization process, favoured by the poor physical properties of the soil. Other elements (NaNH4Ac, KNH4Ac, MnDTPA) were accumulated within the soil as time passed by, as a result of soil status, Mediterranean environmental conditions and crop management. The use of SSC as organic fertilizer represents an effective option to optimize cynara cultivation systems while improving soil quality through enhanced long-lasting organic matter pools.

Effect of long‐term fertilization on soil microbial activities and metabolism in Paulownia plantations

“…The results revealed the OIF treatment was more effective for soil acidification, organic carbon accumulation and fertility improvement, which indicated that it could be an important fertilization technique to improve the soil fertility quality of Paulownia plantations. Long-term application of organic fertilizers contributed to the accumulation of SOM, thereby improving soil fertility, which is consistent with other findings (Lag-Brotons et al, 2015). Our results also revealed that fertilization could significantly increase soil enzyme activity and microbial biomass in the two different-aged Paulownia plantations, especially soil UA, CA, APA, MBC and MBN under the OIF treatment.…”

The use of wastes (organic and inorganic) in land restoration in relation to their characteristics and cost

“…For general purposes, the use of organic amendments in soil rehabilitation and restoration has the main objective of adding and increasing the organic matter and favoring the availability of nutrients for plants (Lag-Brotons et al, 2015). Moreover, the organic amendments influence the structure and physical soil properties, as many works have demonstrated (e.g.…”

Growing a population of cultivated cardoon (Cynara cardunculus var. altilis DC) for further selection as a reference energy crop

“…Energy crops cultivation aims to maximize biomass feedstock obtained per unit of area, minimize production inputs, and avoid land competition with food crops (Lag-Brotons et al, 2015). In addition, environmental co-benefits can be achieved through the sustainable cultivation of energy crops, such as the protection of soil, the increase in terrestrial carbon sinks and reservoirs and the reduction of greenhouse gases emissions (Sims et al, 2006).…”