Potential short-term negative versus positive effects of olive mill-derived biochar on nutrient availability in a calcareous loamy sand soil

Abstract

In the present work, the olive mill solid waste (OMSW)-derived biochar (BC) was produced at various pyrolytic temperatures (300-700˚C) and characterized to investigate its potential negative versus positive application effects on pH, electrical conductivity (EC), and nutrients (P, K, Na, Ca, Mg, Fe, Mn, Zn, and Cu) availability in a calcareous loamy sand soil. Therefore, a greenhouse pot experiment with maize (Zea mays L.) was conducted using treatments consisting of a control (CK), inorganic fertilizer of NPK (INF), and 1% and 3% (w/w) of OMSW-derived BCs. The results showed that BC yield, volatile matter, functional groups, and zeta potential decreased with pyrolytic temperature, whereas BC pH, EC, and its contents of ash and fixed carbon increased with pyrolytic temperature. The changes in the BC properties with increasing pyrolytic temperatures reflected on soil pH, EC and the performance of soil nutrients availability. The BC application, especially with increasing pyrolytic temperature and/or application rate, significantly increased soil pH, EC, NH 4 OAc-extractable K, Na, Ca, and Mg, and ammonium bicarbonate-diethylenetriaminepentaacetic acid (AB-DTPA)-extractable Fe and Zn, while AB-DTPA-extractable Mn decreased. The application of 1% and 3% BC, respectively, increased the NH 4 OAc-extractable K by 2.5 and 5.2fold for BC300, by 3.2 and 8.0-fold for BC500, and by 3.3 and 8.9-fold for BC700 compared with that of untreated soil. The results also showed significant increase in shoot content of K, Na, and Zn, while there was significant decrease in shoot content of P, Ca, Mg, and Mn. Furthermore, no significant effects were observed for maize growth as a result of BC addition. In conclusion, OMSW-derived BC can potentially have positive effects on the enhancement of soil K availability and its plant content but it reduced shoot nutrients, especially for P, Ca, Mg, and Mn; therefore, application of OMSW-derived BC to calcareous soil might be restricted.

Lignite Scaffolding as Slow-Release N-Fertilizer Extended the SN Retention and Inhibited N Losses in Alkaline Calcareous Soils

“…The pH of RL, DL, and LSRNF was determined in a mixture (1:25, w/v) in deionized water using a digital pH meter. The samples were extracted to measure the EC using a digital EC meter . The VM, A, and FC of RL and DL were measured following the standard procedure, developed by the American Society for Testing and Materials (ASTM) .…”

“…The samples were extracted to measure the EC using a digital EC meter. 34 The VM, A, and FC of RL and DL were measured following the standard procedure, developed by the American Society for Testing and Materials (ASTM). 35 The structural stability was identified by XRD.…”

A review on biochar’s effect on soil properties and crop growth

“…Several authors (Senesi andPlaza, 2007;Dias et al, 2010) stated that acidic compounds produced from decomposition of soil organic matter lowered the pH of alkaline soils. For calcareous soils also, biochar additions increased the soil pH (Alazzaz et al, 2020). However, application of acidic biochars produced through slow pyrolysis and steam activation reduced the soil pH between 0.2 and 0.4 units in calcareous soils (Ippolito et al, 2016).…”

“…Biochar itself contain significant quantities of cations like K, Ca, Mg and application of that improved their levels in the soil (Jien and Wang, 2013). Alazzaz et al (2020) reported that biochar derived from the olive mill solid waste should be restricted in calcareous loamy sand soils as it reduced the concentration of P, Ca, Mg and Mn in maize shoots. In calcareous loamy sand soils, biochar application increased the available K, Na, Ca, Mg, AB-DTPA extractable Fe and Mn whereas it reduced AB-DTPA extractable Zn.…”

Biochar: A Surrogate Approach to Modulating Soil Chemical Properties and Germination Parameters of Barley Plants Grown under Multi-Stress Conditions

“…These results are in agreement with previous reports of Joseph and Taylor (2014), Yargicglu et al(2015), PT 350 was found to have the most in uence on soil pH (which decreased) compared to PT 500 and PT 700 . These results could be attributed to the increase in basic oxides and carbonates produced during the pyrolytic process(Alazzaz et al 2020). These results are in line with previous studies(Cardelli et al 2017;Yao et al 2017 andTang et al 2019), which reported that soil pH increased with increasing pyrolysis temperature.…”