Chemical Properties of Some Alkaline Sandy Soils and Their Effects on Phosphorus Dynamics with Bone Char Application as a Renewable Resource of Phosphate Fertilizer

Abstract

AbstractSeveral chemical properties of alkaline soils play an important role in dissolving phosphate minerals, which greatly affect the phosphorous availability to plants. The current study was carried out to assess bone char application on the availability and distribution of phosphorus in some alkaline sandy soils. This incubation experiment was performed by selecting some alkaline soils from different locations in Upper Egypt: Arab El-Awamer (Assiut Governorate), West El-Minia (El-Minia governorate), and New Valley Governorate. Bone char was applied at a dose of 4 g kg−1 soil. The incubation periods lasted for 7, 16, 35, 65, and 84 days. Phosphorus availability in Arab El-Awamer soil increased significantly with applying bone char and was greatly influenced by soil chemical properties and incubation periods. Bone char addition caused a relative increase of available phosphorous in the sequence as follows: Arab El-Awamer soil ˃ New Valley soil ˃ West El-Minia soil. Available phosphorous showed a negative correlation with electrical conductivity, soluble calcium, and soluble sulfate. A significant increase of NH4Cl-Pi, NaHCO3-Pi, NaOH-Pi, HCl-Pi, and residual P fractions occurred in some soils with bone char application. Phosphorus fractions distribution in all soils followed: HCl-P ˃ residual P ˃ NaHCO3-P ˃ NaOH-P ˃ NH4Cl-P. The correlation between phosphorus availability and phosphorus fractions was positive. Our results focus on the importance of using bone char as an amendment in P-poor alkaline soils for improving phosphorus availability. So, bone char is an effective technique for sustainable agriculture because it is a clean and renewable resource of phosphate fertilizers.