Photopedogenesis: A Fundamental Soil Forming Process in Rock Weathering and Rhizospheric Stability on Earth and Lunar Surface

Abstract

Sunlight penetrates into soil (2mm) with water based on simple classical experiment followed by subsequent interactions depending upon several soil-microbe-plant related factors in the rhizosphere. Beyond the soil, even the fresh rock under rain (wetness) promotes the growth of lichen, phototrophs, mosses, blue green algae forming mat, hyphae and root. The biomass so produced undergoes decomposition and gradually helps in weathering of the rock surface, where contribution of light in presence of moisture is vital. In almost all known soil forming processes, horizonation begins at surface of the parent material forming “O” horizon and subsequent A, B horizons over C horizon. The “O” horizon is the outcome of the contribution of sunlight and moisture. In 1996, Theory of Photopedology was initially developed, which was subsequently improved to Photopedogenesis in 2006 as being the fundamental soil forming process. Chandrayan 1 in India discovered signals for water on lunar surface (https://images.app.goo.gl/8BNb2fRoj4MXHP1C6) having weatherable rocks (basalt) and minerals (pyroxene). Photopedogenesis needs to be expanded on lunar surface for soil genesis by Indian Space Research Organization (ISRO).