Enhancing Soil Organic Carbon Content and Water Retention Using Polyvinyl Alcohol Cross-linked with Chitosan and Pectin

Abstract

Soil organic carbon is considered a candidate without a substitute to be an important indicator of soil degradation by monitoring its amount and changes over time. Organic compounds such as chitosan (CS) and pectin (PC) can increase organic matter content in soils and provide a carbon source for microbes. Organic nanoparticles (NPs) were prepared by polymerization of CS and PC with polyvinyl alcohol (PVA), loaded with NPK nutrients, and evaluated by transmission electron microscope as well as zeta-potential (ZP). This study aims to test the effect of organic NPs on soil organic carbon (SOC) content, available water capacity (AWC), and growth of wheat plant. Thus, a pot experiment was conducted using clay soil. The treatments were NPK at two levels, viz., 50 and 85% of the recommended doses in combination with CS/PVA and PC/PVA as nano-carrier materials, as well as control treatment (85% NPK). Results showed that the loading of organic NPs with NPK nutrients obviously increases the solution stability and the positive as well as negative charges for CS/PVA (50.30 mV) and PC/PVA (− 17.80 mV), respectively. Furthermore, the using of NPK nano-fertilizers was significant for all the studied properties. Likewise, the addition of CS/PVA loaded with NPK decreased soil ZP at a range of − 13.00 to − 16.90 mV. Besides, it shows better carbon-cycling activity by increasing SOC at a range of 9.71 to 11.68 g kg−1. The PC/PVA loaded with 50%NPK not only increases AWC with a rate of 18.23% but also sustains water-release synchronization to meet wheat plant demands.