Impact of the application of biochar previously used in domestic wastewater treatment on the growth of lettuce (Lactuca sativa)
Year: 2022
Type: article
Abstract: Biochar has gained attention in agricultural studies due to its ability to ameliorate soil conditions. However, due to its low nutrient content, positive effects on plant growth are generally only observed if combined with mineral fertilizers or manures. The study aimed to test the hypothesis that biochar used to treat domestic wastewater can become enriched with nutrients and subsequently serve as a better soil amendment. The impact of the application of biochar used as substrate in a filter for domestic wastewater treatment (TB) on the growth of lettuce (Lactuca sativa var. crispa) plant was evaluated. Its effect on plant growth was compared to pure biochar (BC) using bare soil as a control. The biochars were applied with and without fertilizer using 3 biochar application rates (10, 20 and 30 t/ha). Results showed that biochar does not become enriched after wastewater purification in the short run. Instead, there was a reduction in the mineral composition, available phosphorus and pH in TB compared to BC. Only the BC treatments were significantly different (p=0.001) from the control. However, higher biomass production at 30 t/ha was observed in BC (+322%) and TB (+142%), compared with the unfertilized control. There were no significant differences in biomass production between the biochar and control treatments for application rates below 30 t/ha. Fertilization significantly (p=0.024) improved biomass production with the BC30+F treatments demonstrating the highest performance (+315%) compared to the fertilized control.
Language: English
Subfield: Soil Science
Domain: Life Sciences
Open Access status: diamond
Funder: Pan African University
OpenAlex ID: W4296667862