Preparation and properties of stover cellulose grafted poly (acrylic acid‐potassium humate) with water‐retention and slow‐release fertilizer

Abstract To improve the utilization of stover and fertilizer and also save water resources, a degradable slow‐release fertilizer of corn stover cellulose graft poly (acrylic acid‐potassium humate) (CSC‐ g ‐P(AA‐KHA)) was prepared using corn stover cellulose (CSC), acrylic acid (AA) and potassium humate (KHA) by aqueous solution polymerization. Characterization of CSC‐ g ‐P(AA‐KHA) with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) techniques provided evidence for the successful preparation. The product prepared exhibited excellent water absorbency (792.89 g·g −1 and 72.69 g·g −1 in deionized water and 0.9 wt% NaCl solution, respectively) and enhanced soil's capacity of water holding and water retention. After 5 cycles, the water absorptivities of CSC‐ g ‐P(AA‐KHA) in deionized water and 0.9 wt% NaCl solution were 51.71% and 49.97% of their initial water absorption, respectively. The degradation rate of CSC‐ g ‐P(AA‐KHA) was 32.02% after 50 days. Soil column leaching test and pot experiment demonstrated the slow‐release effect and plant growth promotion of CSC‐ g ‐P(AA‐KHA). CSC‐ g ‐P(AA‐KHA) showed desirable application potential in agriculture and is expected to become a functional fertilizer that integrates water absorbing, water‐holding and slow‐release properties.