Developing an environmental friendly approach for enhancing water retention with the amendment of water-absorbing polymer and fertilizers

Abstract

The effect of climate/environmental change has resulted in adverse water stress conditions which necessitates the sustainable approaches for improving the water use efficiency to boost agricultural production in Central Asia. Water-absorbing polymer (WAP) has emerged as one of the amendments for soil water stress management. WAP are chemically cross-linked structure capable of absorbing and storing a large amount of water. The agricultural land has different levels of fertilizers which can influence the performance of WAP because of its sensitivity due to external ionic medium. Therefore, the combined or hybrid use of WAP and organic/ inorganic fertilizers may inhibit the functionality of WAP, which needs to be thoroughly investigated. This study demonstrates the performance of two different WAPs (a commercially WAP (crosslinked potassium polyacrylate) and a laboratory synthesized WAP (crosslinked fly ash-polyacrylate superabsorbent composite)) with varying combinations of fertilizers in silt loam (agrarian soil). The combined use of fertilizers and WAP have improved the water retention properties of soils due to modification in the soil pore volume for both the WAPs. Quantification from water retention properties revealed a significant increase in plant wilting time (PWT) and plant available water content (PAWC) under the combined influence of fertilizers and WAP amended soils, indicating the possibility of high-water availability to plant roots. The study suggests the potential of WAPs as an efficient soil conditioner even in the presence of fertilizer for countering the negative impacts of water stress conditions. WAPs might minimize the requirement for chemical fertilizers, which helps to enhance the climate/environmental change and agriculture sector in the Central Asian region.