Communities of arbuscular mycorrhizal fungi (AMF) in plant roots improve host plant growth. In this study, AMF communities in the roots of the sago palm (Metroxylon sagu Rottb.) were investigated in mineral soil (MS) and shallow peat soil (SPS) in Sarawak, Malaysia. MS exhibited lower moisture content (MS, 38.1; SPS, 79.8%), higher pH (H2O) (MS, 4.6; SPS, 4.1), higher soil bulk density (MS, 1.03; SPS, 0.20 g cm−3), and higher nitrogen content (MS, 16.9; SPS, 2.7 kg m−3) than SPS at the same soil depth, while the phosphorus (P) content (Bray II) (MS, 1.6; SPS, 1.9 g P2O5 m−3) was similar. The AMF colonization rate was significantly lower in SPS (39.2 ± 12.5%) than in MS (73.2 ± 4.6%). The higher number of AMF operational taxonomic units (OTUs) was detected by amplicon sequencing of the partial small-subunit rRNA gene (MS, 78; SPS, 50). A neighbor-joining tree of obtained OTUs revealed that they belonged to Acaulosporaceae, Ambisporaceae, Claroideoglomeraceae, Gigasporaceae, and Glomeraceae. The lower abundance and diversity of AMF in SPS are possibly caused by abiotic factors, including soil physicochemical properties. Glomus and Acaulospora species detected in SPS might have strong tolerance against acidity and high soil moisture content.

Adopting environmentally friendly or green technology and incorporating new alternative substrates for a sustainable agricultural industry has garnered the attention of numerous researchers. Although super absorbent hydrogels have exhibited great potential, natural hydrogel-based absorbents have gained more interest due to their environmentally safe properties. The sources for the novel green polymer are easily obtained from agricultural wastes, such as polysaccharides, agarose, chitosan, and mucilage, with zero to minimal cost. The polymer also offers several attributes, including water usage and cost efficiencies, versatile application, and increasing plant growth. Furthermore, the polymer can act as a carrier agent and aid in improving the properties of planting mediums. The present review focuses on natural and chemical hydrogel-based polymers. It discusses their potential application in sustainable agriculture and the conservation of ecosystems by providing balanced protection for seeds, plants, and soil. Future perspectives based on previous investigations are also presented.

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