Long-Term Comparative Evaluation of Organic and Conventional Farming Systems on Sugar Yield, Soil Fertility, and Economic Returns in Sugarcane
摘要
A long-term field experiment was conducted to evaluate the sustainability and performance of organic and conventional sugarcane farming systems under the tropical semi-arid conditions of coastal Andhra Pradesh, India. The study ran for 14 consecutive years (2011–12 to 2024–25) at the Regional Agricultural Research Station, Anakapalle, using a randomized block design with two farming systems: organic farming (OF) and conventional farming (CF). The investigation assessed cane yield, yield attributes, juice quality, soil properties, microbial populations, and economic returns. Two-way ANOVA showed that treatment effects had no significant impact on cane yield and yield attributes, juice quality parameters, economic elements, soil physicochemical, nutrient, and microbe parameters, except phosphate-solubilizing bacteria (PSB), indicating comparable performance of the two farming systems. Organic farming recorded numerically higher mean values for cane yield (72.38 t ha⁻1), sugar yield (9.64 t ha⁻1), sucrose (18.75%), commercial cane sugar (13.05%), soil organic carbon (0.71%), and net returns (₹180,527 ha⁻1), whereas conventional farming maintained higher available soil nitrogen, phosphorus, and potassium. Soil health indicators were significantly improved under organic farming, evidenced by higher soil organic carbon (0.71%), lower electrical conductivity (0.20 dS m⁻1), and stable pH, although treatment differences were not statistically significant. Among the microbial parameters, the population of phosphate-solubilizing bacteria (PSB) was the only trait with a significant treatment effect. Organic farming had much higher counts at 13.81 × 103 cfu g⁻1 compared to conventional farming at 6.67 × 103 cfu g⁻1, while the differences in Azospirillum and Azotobacter populations were not significant. Economic analysis showed similar profitability between the two farming systems. Organic farming had slightly higher net returns (₹180,527 ha⁻1) and a benefit–cost ratio (0.88), but these differences were not statistically significant. This study was conducted at a single location with a single sugarcane variety, so the findings may not generalize to all agro-climatic conditions. More validation is necessary before applying the results broadly. Future research should test multiple sugarcane varieties across different agro-ecological regions with long-term organic management.