Effect of a superabsorbent polymer on the growth of Panicum antidotale and nitrogen leaching

A pot trial was conducted to investigate the effect of a superabsorbent polymer on the growth of Panicum antidotale and nitrogen leaching in three soil textures (heavy, medium and light-textured soils) and three irrigation regimes (4, 8, and 12-day intervals). Results showed that the greatest amount of plant growth and dry biomass was obtained at moderate-textured soil and 14-day irrigation interval. According to the obtained results, the effects of polymer, irrigation regime and soil texture on dry matter production, plant height, and nitrogen leaching were significant. Furthermore, the interaction effects of irrigation regimes and soil texture on dry matter production and nitrogen leaching were significant. The highest dry matter production (7.2 g) was obtained at medium-textured soil with polymer at a four-day irrigation interval. In treatments without polymer at a light-textured soil and a 12-day irrigation interval, plants were lost before harvesting. Our results clearly showed that the studied treatments caused to the increased height of Panicum antidotale. Statistically, the effects of a four-day irrigation interval and a heavy-textured soil were the most significant. In addition, the effects of polymer, irrigation regimes, and soil texture treatments on nitrogen leaching were significant. The interaction effects of irrigation and soil treatments showed that the amount of nitrogen leaching decreased by increasing irrigation intervals. The application of polymer obviously decreased nitrogen leaching from 880 mg N/l in control treatment to 550 mg N/l in soils containing polymer material.