Energy flow, eco-efficiency, and economic circulation with recycled industrial waste compost application in wheat and subsequent rice farming

Abstract

The World Bank estimates that industries generate 2 billion tonnes of waste annually, contributing to pollution, resource inefficiencies, and environmental degradation. These issues emphasize the need for sustainable waste management. Similarly, the rice-wheat cropping system in South Asia faces challenges like declining soil fertility, excessive chemical use, and low resource efficiency, leading to reduced productivity, environmental impact, and climate vulnerability. To create long-run eco-friendly farming, this study designed to use compost derived from recycled industrial by-products to lower the fertilizer load and input energy in wheat-rice farming. A split-plot design was used for the study from 2018 to 2021. Four nutrient sources were applied in the main plot, and a combination of three industrial wastes and waste decomposers made into nine treatment combinations were used in the subplot. Based on an average of four years of data, in the main plot, treatment 100 % crop nutrition practices (CNP) of nitrogen (N)-phosphorus (P)-potassium (K) + 5 kg zinc (Zn) + 5 kg iron (Fe) had 62.0 % (wheat) and 37.8 % (rice) more grain energy output than control. On the other hand, compared to bagasse + Pleurotus sajor-caju, the sub-plot with treatment carpet waste + Trichoderma viride showed 36.4 % (wheat) and 21.4 % (rice) higher grain energy output. Further, in the main plot, 100 % CNP of NP₂O₅-K₂O + 5 kg Fe + 5 kg Zn had found a 25.3 % (wheat) and 36.7 % (rice) higher energy BC ratio than the control. Furthermore, compared to bagasse + Pleurotus sajor-caju, carpet waste + Trichoderma viride had an 18.2 and 21.3 % higher energy BC ratio of wheat and rice in the sub-plot treatment. Regarding a different parameter, the 100 % CNP of N-P₂O₅-K₂O + 5 kg Fe + 5 kg Zn in the main plot showed 19.4 and 33.4 % higher energy intensity in economic terms (EIET) of rice and wheat, respectively, compared to the control. Further, carpet waste + Trichoderma viride had 14.6 and 10.4 % more EIET of wheat and rice than bagasse + Pleurotus sajor-caju in the subplot. Based on the combined effect of, 100 % CNP of N-P₂O₅-K₂O + 5 kg Fe + 5 kg Zn × Trichoderma viride + carpet waste was noted to be a maximum of 1595.0 and 1229.4 Mega joule per day (MJ day⁻¹) (1 MJ = 106 J) energy output efficiency (EOE) of wheat and rice, respectively. Moreover, the net energy return was higher at 1187 and 834 US$ ha⁻¹ of wheat and rice was observed in 100 % CNP of N-P₂O₅-K₂O + 5 kg Fe + 5 kg Zn × Trichoderma viride + carpet waste, respectively. In the case of wheat, biomass energy productivity had a negative relationship with both total energy output and biomass net energy, according to the Pearson correlation matrix. This study highlights the potential of recycled industrial waste compost (IWC) to reduce synthetic input reliance, enhance EUE, and establish a cost-effective energy circulation system in the RWS. It will fulfil the agenda of the Food and Agriculture Organization (FAO)sEnergy-Smart Food (ESF) program to achieve energy sustainability in food systems and thus offers a scalable model for sustainable agriculture with future implications for climate-resilient farming and eco-friendly policy development.