In a recent study published in Paddy and Water Environment, Anjali Thaitharanikathil Babu, Anand Madhavan, Akhilesh Kottikkathara Bhanuvikraman, and Umalakshmi Kalayamkudath Subran investigated the profound impact of poultry litter-derived biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More (PLB) on rice yield and soil fertility in Kerala, India. The study, conducted from November 2022 to March 2023, compared the effects of various bio-amendments, mineral fertilizers, and current farming practices on rice growth and soil characteristics. The findings underscore the remarkable potential of PLB for sustainable agriculture, particularly in paddy wetlands prone to excessive synthetic fertilizer use and poultry litter application.

A key takeaway from this research is the significant improvement in rice yield achieved with biochar treatments. Specifically, the treatment where biochar was prepared at 300∘C with a 60-minute residence timeResidence time refers to the duration that the biomass is heated during the pyrolysis process. The residence time can influence the properties of the biochar produced.   More (PLB300-60) yielded an impressive 39.06 t/ha of rice. This is six times higher than the control plots (6.4 t/ha), more than double that of mineral fertilizer application (16.6 t/ha), and current farming practices (17.5 t/ha), and 1.5 times greater than direct poultry litter application (24.4 t/ha). This highlights PLB as a superior alternative for boosting agricultural productivity.

Beyond yield, the study observed a noticeable improvement in the physicochemical properties of the soil under biochar treatments. The biochar amendments, particularly PLB300-60, were found to enhance soil pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More, electrical conductivity, total organic carbon (TOC), organic matter (OM), and cation exchange capacity (CEC). For instance, PLB300-60 exhibited higher electrical conductivity ( 17.55±0.5 mS/cm) and a favorable pH of 8.1±0.02 compared to raw poultry litter at 7.6±0.03. This suggests that biochar effectively modifies soil characteristics to create a more conducive environment for plant growth.

The research also delved into the impact on soil microbial activity. All three biochar-amended treatments (T3, T4, and T5) recorded the highest microbial biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More carbon (MBC) during the jointing and booting stage (day 60). For example, PLB300-60 (T4) showed MBC values ranging from 233.7−240.3 μg/g during this period. This accelerated carbon mineralization is attributed to biochar-mediated microbial metabolism, indicating a healthier soil ecosystem. Furthermore, soil dehydrogenase activity, a key indicator of microbial activity, was also significantly higher in biochar-treated topsoils, with T4 exhibiting 123.51 μg/g during pre-cultivation. Nutrient availability in the soil was also positively influenced by biochar. The study found that nutrients such as nitrogen, phosphorus, potassium, magnesium, and iron were more concentrated in the biochar-treated soils during the pre-cultivation stage. Available phosphorus, for instance, was significantly higher in treatments T3 (51.3−58.2 kg/ha), T4 (55.3−46.2 kg/ha), and T5 (47−30 kg/ha) in the pre-cultivation soil. This increased nutrient retention and bioavailability are crucial for sustaining crop production.

The vegetative growth parameters, including crop height, root and shoot length, number of leaves, and root and shoot dry weight, were also notably enhanced by biochar application. Treatment No. 5 (PLB350-30), specifically, showed remarkably high vegetative growth, with crop height reaching 113.3±2.8 cm, root length at 24.68 cm, and shoot length at 29±0.5 cm. This confirms that biochar promotes robust plant development, contributing to overall higher yields.

This master’s thesis strongly advocates for the use of biochar derived from waste materials like poultry litter as a sustainable approach to enhance soil fertility, rice growth, and yield. This strategy not only supports a circular bio-economy through sustainable waste management but also promotes good agricultural practices that protect paddy wetlands and the surrounding ecosystem in Kerala. Future research should focus on long-term field trials across various cropping seasons and explore the synergistic effects of poultry litter biochar with other organic fertilizers.

Source: Babu, A. T., Madhavan, A., Bhanuvikraman, A. K., & Subran, U. K. (2025). Poultry litter-derived biochar for sustainable agriculture: implications for rice yield and soil fertility enhancement. Paddy and Water Environment.