Effects of Converting Grassland to Rainfed Areas on Soil Nutrients and Plant Growth

Aim :

Land use change (LUC) not only affects the plant and soil functional properties, but also influences soil nutrients efficiency. This research was carried out to examine the effect of grassland conversion to dry farming on the efficiency of bio-mineral nutrients in semi-arid loamy soils of northwestern Iran.

Animal manure (AM: 100 and 200 g. Kg-1), useful micro-organisms (UMOs: 1 and 2%), superabsorbent polymers (SAP: 10 and 30 g. Kg-1) and potassium nano-silicate (PNS: 500 and 1000 mg. Kg-1) were used for grass Festuca ovina L. cultivated in grassland and dry farming soil at a completely randomized factorial design.

Based on the results, LUC strongly affected the efficiency of soil nutrients especially PNS (P ≤0.01) where the highest and lowest effects of different nutrients were observed under dry farming and grassland, respectively. A maximum difference of 24.0%, 45.0% and 24.0% were observed in plant biomass, chlorophyll, moisture content, respectively, using 200 g. Kg-1 AM and 30 g. Kg-1 SAP in soil of grassland and dry farming. Also, maximum difference of 71.0% and 67.0% occurred at soil phosphorus and organic matter, respectively between grassland and dry farming.

depending on the type and amount of fertilizer, convert the grasslands to rainfed areas significantly influence plant performance and soil improvement. Overall, due to the undisturbed soil, grasslands show a better performance than rainfed areas under any rehabilitation program.