Sustainability of soil fertility status after 3-year crop rotation in sandy soils in Egypt [electronic resource].

Includes references.

A three years field experimsent was carried out at El-Bustan area - west Nile Delta which represents a vast area of the newly reclaimed sandy soils (98.5% sand), poor in organic matter, both macro- and micro-nutrients as well as water holding capacity. The main objective of this experiment was to promote sustainability and fertility build up in sandy soils. A split plot design with three factors in three replications was followed. a) The first (main plots) is the water quantity at two levels: ReqUired irrigation water (R) = Evapotranspirtion (ETc) + 20% ETc and Farmer (f) = R + 30% of R, using sprinkler irrigation system. b) The second factor (split plots) is the crop rotation: the prevailing rotation (RoU) and intensive (proposed) rotation (Rot.n). In (RoU) : wheat - groundnut were grown in the first and the second years while berseem - groundnut in the 3 third year. Crops grown in (Rot. n) were berseem-groundnut, wheat-sesame and peasunflower- maize in the first, second and third year, respectively. c) The third factor (split- split plots) is balanced N, Pand K levels, (low, medium and high) with and without organic manure. Representive soil samples were taken at the starting of the experiment (1996) and after the three years (1999) to follow up changes in organic matter content (O.M.), and macro-& micronutrients. Samples which were taken at the start indicate that average organic matter content was 0.25%; and 9.25, 3, 114, 2.05, 1.24 and 0.32 ppm for available N, P, K, Fe, Mn and Zn, respectively. The most important flndlngs are: Soil organic matter content was relatively increased by organic manure application. • Organic manure induced marked Increases in the available soil P by about 46.3% over zero- organic manure, 20.07% and 5.96% for available K and available N respectively. • Values of available Fe, Mn and Zn in the soil were increased by organic manure application. Crop rotation and water quantity had no remarkable effects on the soil fertility build up.

1