Pig manure digestate‐derived biochar for soil management and crop cultivation in heavy metals contaminated soil

Abstract

Management of heavy metal‐contaminated soil under drought and other harsh hydrological conditions is critical for protecting soil ecosystem services. In this study, we examined the effect of pig manure digestate‐derived biochar as a soil amendment (15 t ha−1) with N fertilizer (180 kg ha−1) on soil and plant heavy metal levels and nutrient availability under various moisture regimes (optimal moisture ~15%, drought condition ≤5%, and flooded condition ≥35% wt.). It was observed that biochar applications significantly decreased heavy metals in the spring wheat plants, lowering Cr by 90%, Ni by 50%, Cd by 9% and Pb by 34% compared to non‐biochar (control) treatments. However, the pig digestate‐derived biochar increased heavy metals in soil under all moisture regimes, increasing soil Cr by 21%, Ni by 43%, Cu by 55%, Zn by 70%, and Pb by 12%. The availability of macroelements also increased with the biochar applications under the optimum moisture regimes in both soil and plants, increasing Mg2+ by 11%, P by 4%, K+ by 50%, and Ca2+ by 56% in the soil, and Mg2+ by 13%, P by 69%, K+ by 29, and Ca2+ by 39% in plants. Biochar addition also improved chlorophyll fluorescence (CF) levels in the crop for the entire season (12th to 62nd day) and the aboveground crop biomass and dry matter contents both increased. Consequently, the use of pig manure digestate‐derived biochar with N fertilizer under normal moisture conditions was able to reduce heavy metal availability to plants and thus could be used in contaminated soils to maintain better crop growth and development.

Nitrogen flow in livestock waste system towards an efficient circular economy in agriculture

“…The biochar with pig manure as the primary feedstock was produced by pyrolysis under oxygen limited conditions in a cylindrical furnace for 5–6 hours at a temperature of 550°C per minute (Ayaz et al, 2022; Boostani et al, 2019). Physicochemical properties of the biochar were analysed by standard laboratory methods.…”

Role of biochar toward carbon neutrality

“…Besides, application of biochar to the soil environment promotes soil health, thus leading to multifaceted benefits including enhancing plant growth, and increasing soil diversity on contaminated land (Fig. 2b) (Ayaz et al 2022;Baveye 2021;Bolan et al 2022). The restored ecosystems may also serve as a good place for leisure and entertainment (Fig.…”

Aging of colloidal contaminants and pathogens in the soil environment: Implications for nanoplastic and COVID‐19 risk mitigation

“…First of all, organic amendments (e.g., compost, manure and biochar) applied to the soil increase the SOM pool (Abagandura et al, 2022 ; Armolaitis et al, 2022 ; de Figueiredo et al, 2021 ; Dong et al, 2022 ), which may reduce NP mobility via enhanced eco‐corona formation (Figure 6 ). Secondly, these amendments directly immobilize NP via heteroaggregation or adsorption (Abdoul Magid et al, 2021 ; Ayaz et al, 2022 ; Tong et al, 2020 ; L. Wang et al, 2022 ). Besides, it is widely accepted that fresh organic amendments will stimulate the activities of soil microorganisms, leading to an elevated mineralization rate of aged SOM (also known as the positive priming effect) (Cordova et al, 2022 ; Fontaine et al, 2003 ; Jiang et al, 2022 ; Kuzyakov et al, 2000 ; Y. Zhang et al, 2022 ).…”