Effect of Phosphogypsum on Formation and Development of Soil Surface Crust and Wheat Crop Growth
Soil crusts are formed at soil surface due to the impacts of raindrops and break of aggregates, resulting in reduction of seedling emergence, reduction soil infiltration rate and increasing of runoff which induces soil erosion. In order to reduce the negative effects of crusts, an experiment was conducted under natural rainfall to determine the effect of adding Phosphogypsum (PG) on the formation and development of soil surface crust and its effect on the wheat yield. Two soil textures from two different locations, clay and silty clay were used. Three levels of PG (0, 5, and 10%) added on the surface of each soil and sown with wheat seeds. The results showed that thickness, penetration resistance and bulk density of the crust were decreased, in addition to decreasing of fine soil fractions in the crust, when PG levels were increased.
The results also showed that the above characteristics of the crust were increased with increasing of rainstorms duration. Finally, the results showed that the wheat crop characteristics, such as plant height, the number of grains in the spike, seed weight and dry weight were increased by increasing of PG added levels.