Physico-chemical properties and Manganese concentration effects on biochemical activities in cereals crops grown in degraded soil

Degraded soil has now become an important factor in agricultural economy. Human activities are responsible for land degradation, as construction of large-scale canals for irrigation purposes, deforestation and faulty land use, salinization, drought and water-logging. These processes also reduce the availability of essential minerals. Manganese is an essential micronutrient for plant growth, development and intervening in several type of metabolic activity, mainly in photosynthesis and chlorophyll concentration in different types of plants. Manganese is also essential co-factor for the oxygen-evolving complex of the photosynthetic machinery of plants life cycle and catalyzing the water-splitting reaction in photosynthetic- II process. Nevertheless, excess amount of Manganese is available in soil for plant affecting the plant’s growth and become toxic for them. Manganese phytotoxicity is manifested in the reduction of plant biomass, photosynthetic rate and different type of bio-chemical disorders like; oxidative stress, chlorosis on young leaves, necrotic dark spot on mature leaves and crinkled leaves. An important role of antioxidative system in plant in high amount of Manganese has been also reported as a defense mechanism for plants. In the collected sample of degraded soil, the availability of different types of elements is very poor in concentration and other physico-chemical properties are also reduced in degraded soil.