ABSTRACT
This study aimed to conduct a meta-analysis (MA) of systematic review data on poultry litter biochar (PLB) to answer the following questions: (i) What are the major studies regarding this worldwide? (ii) Which soil chemical attributes are the most affected? and (iii) Does PLB improve soil quality and crop productivity? MA revealed that the application of PLB significantly changed several key soil attributes, including pH, cation exchange capacity (CEC), and nitrogen, carbon, potassium, calcium, magnesium, and aluminum content. Specifically, MA showed that PLB decreased Al3+ in the soil by 71% while increasing pH, N, C, and CEC by 16, 20, 36, and 82%, respectively. This significant increase in CEC was associated with the addition of Ca2+, Mg2+, and K+ cations by 43, 202, and 636%, respectively. It was verified that PLB serves a dual function: it corrects soil acidity and pH while also enhancing the content of key nutrients, such as C and N. This study broadens the understanding of the potential of reusing poultry litter in biochar production, offering valuable data for developing strategies to improve both soil health and fertility.
Key words:
waste reuse; pyrolysis; soil health; nutrient availability; plant production
HIGHLIGHTS:
Biochar from poultry litter enhances soil by modifying pH, nutrient content, and capacity to retain cations.
Poultry litter biochar decreased Al3+ in soil by 71% while increasing pH, N, C, and CEC by 16, 20, 36, and 82%, respectively.
The meta-analysis revealed that poultry litter biochar is globally used to enhance soil quality.
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CI - Confidence interval; CEC - Cation exchange capacity; C - Total carbon; N - Total nitrogen. A screening process was conducted using 1,800 scientific studies found across the three major global scientific search platforms, utilizing the access key phrase “poultry litter and biochar.” The studies were conducted between 2010 and 2020. As a result, 25 datasets originating from all continents were filtered, enabling the statistical analysis of the impact of biochar on eight key soil attributes.
CI - Confidence interval; I2 - Heterogeneity between fixed effects of the two contrasting conditions (larger, more heterogeneous); t2, statistic of uniformity of the random weights assigned to the studies (larger, more heterogeneous)
CI - Confidence interval; I2 - Heterogeneity between fixed effects of the two contrasting conditions (larger, more heterogeneous); t2 - Statistic of uniformity of the random weights assigned to the studies (larger, more heterogeneous)
CI - Confidence interval; I2 - Heterogeneity between fixed effects of the two contrasting conditions (larger, more heterogeneous); t2 - Statistic of uniformity of the random weights assigned to the studies (larger, more heterogeneous)