Potential of oribatid mites in biodegradation and mineralization for enhancing plant productivity

Authors : Mohamed Abdul HAQ

Pages : 101-122

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Publication Date : 2019-07-31

Article Type : Research Paper

Abstract :The degradation of litter is an essential process of the soil ecosystem leading to nutrient cycling and is mediated by a heterogeneous group of soil organisms. Oribatid mites represent one of the predominant agents of litter biodegradation in the soil. The ubiquitous presence and extensive diversity of this group of mites make them integral to the process of mineralization of litter in almost all types of soil ecosystems. However, an overall assessment of the mineralization potential of different groups of oribatid mites depicts the relative advantage of lower groups of oribatids, namely the lohmannoid and phthiracaroid members, in the degradation of leafy and woody elements of litter. Degradation of such complex materials primarily necessitates additional qualities such as strong and well developed oral and holding appendages, and the presence of the necessary enteric microflora and associated enzymes, for on-going degradation. In-depth field and laboratory studies of two representative species of the above two groups of mites, viz. Atropacarus ( Hoplophorella ) chaliyamensis Haq and Xavier, 2005 and Heptacarus hirsutus Wallwork, 1964, with the vegetable crop Vigna unguiculata , clearly demonstrated that these species make a remarkable contribution to the process of nutrient cycling. The combined feeding activity of these two species on the woody elements of litter was found to enhance the release of nitrogen, phosphorous and potassium, as evidenced by the increased concentration of these minerals in fecal pellets. However, a decrease in the levels of calcium and magnesium was observed in the fecal pellets. The decrease in calcium may be accounted for by its immediate requirement in body maintenance. The impact of oriculture on plant productivity was evidenced through increased plant growth, higher yield and better quality of the pods produced by the treated plants.
Keywords : Oribatid mites, biodegradation, nutrient cycling, fertility, plant productivity, oriculture