With unprecedented global climate changes, rice crop cultivation under rainfed conditions encounters alternate wetting and drying cycles with water and nutrient stress, which leads to poor yield, quality, and productivity. A modified cellulose-based, slow urea-releasing and water-retaining system from bamboo is developed for rainfed rice crops, to overcome such challenges to emerging rice crops and improve soil health for subsequent crop cycles. Bamboo was delignified to expose the cellulose and subsequent phosphorylation (DPB), followed by strategic urea infiltration and melting to deposit it into the microporous matrix. The melted DPB urea (MDU) presents a zone of influence of 52.5 cm