Effects of Surface Soil Removal (Simulated Erosion) and Fertilizer Application on Wheat Yield

An experiment involving erosion simulation was conducted at the Soil and Water Con-servation Research Center of the University of Tehran. A split-factorial plot with four replications was designed. Five soil desurfacing treatments of blank, ۵, ۱۰, ۱۵, and ۲۰ cm of soil surface removal (E۰, E۵, E۱۰, E۱۵, and E۲۰) were carried out, respectively. Fertilizer treatments were ۰, ۶۵, and ۱۳۰ kg ha-۱ of urea (equal to ۰, ۳۰, and ۶۰ kg ha-۱ of pure N) and ۰, ۱۰۷, and ۲۱۴ kg ha-۱ of triple super phosphate (equal to ۰, ۵۰, and ۱۰۰ kg ha-۱ of P۲O۵). Wheat (Triticum aestivum), Sardary cultivar, was cultivated in November ۲۰۰۱. To-tal precipitation was ۲۲۳ mm during the growing season and ۳۳۶ mm for the whole year (۲۳ September ۲۰۰۱–۲۲ September ۲۰۰۲). In order to reduce the effect of drought stress, three supplementary irrigations were applied during the growing season (۱۳mm each). The crop was harvested in July and plant density recorded. Grain, dry matter and straw yields, as well as ۱,۰۰۰ grain weight were determined. The results showed that erosion had a significant effect (P<۰.۰۵) only on dry matter and straw yields. Each centimeter of soil surface removal, induced a reduction of ۰.۸% in dry matter. Phosphorus fertilizer had a significant effect (P<۰.۰۱) on yield parameters, relatively compensating the negative ef-fects of erosion. Nitrogen fertilizer did not show any significant effect on the determined parameters.

کلیدواژه ها:

Erosion ، Wheat ، Desurfacing ، Productivity ، Soil surface removal