Effect of Co-applying Different Nitrogen Fertilizers with Bone Char on Enhancing Phosphorus Release in Calcium Carbonate-Rich Soil: an Incubation Study

Abstract

The vision of this study is to find a way for increasing phosphorus release from bone char. An incubation experiment was conducted to study the effect of co-applying different nitrogen fertilizer types with bone char (BC) on the availability and distribution of phosphorus in calcium carbonate-rich soil. The experiment contains the following treatments: soil without any nitrogen fertilizer (BC only), soil + ammonium sulfate (BC + AS), soil + ammonium nitrate (BC + AN), and soil + urea (BC + U). Bone char was added to all treatments at a dose of 4 g kg−1 soil. Co-applying bone char with all nitrogen fertilizers caused a significant decrease in pH and increased significantly phosphorus availability in the soil. The concentrations of soil available phosphorus increased from 8.05 mg kg−1 soil for BC treatment to 8.99, 8.90, and 10.16 mg kg−1 soil for BC + AS, BC + AN, and BC + U treatments, respectively, at the end of incubation. Significant increases in soil available phosphorus were observed with increasing incubation periods in all treatments. The effectiveness of the treatments on the soil available phosphorus increase was in the order of BC + U > BC + AS > BC + AN > BC. Nitrogen fertilization treatments significantly increased the NaHCO3-Pi concentrations compared to the BC treatment. Urea application to the soil increased significantly the NaOH-Pi fraction compared to other treatments at day 10 of incubation. Changes in HCl-Pi and Res-P fractions were non-significant in all treatments under nitrogen fertilization. According to the findings, co-applying bone char with nitrogen fertilizers is an agronomic practice that improves phosphorus availability in calcium carbonate-rich soil, thence it is preferable to add urea rather than other nitrogen fertilizers. This study explores a sustainable management strategy to find cost-effective and environmentally friendly alternatives to phosphate fertilizers.

Influences of nitrogen input forms and levels on phosphorus availability in karst grassland soils

“…In our study, different forms of nitrogen exhibited varied effects on the available phosphorus, consistently following the order in both yellow soil and limestone soil: NH 4 NO 3 and Urea >NH 4 Cl > Ca(NO 3 ) 2 (Figures 3, 4). This pattern was consistent with Amin's (2023) research on the efficiency of different N fertilizers in increasing P availability. The differential effects of N forms on soil available P can be attributed to several factors.…”

Effects of combined nitrogen and phosphorus application on soil phosphorus fractions in alfalfa (Medicago sativa L.) production in China

“…Application of N and P fertilizers, and transformation, accumulation, and availability of P in the soil has garnered increasing interest ( Guera and Adriel, 2022 ; Liu et al., 2023 ), as has classification, spatial distribution, and bioavailability of soil P ( Zeng et al., 2022 ). However, most of the existing studies have been on single application of N or P fertilizers ( Amin, 2023 ; Huang et al., 2023 ), and the impact of combined N and P fertilization on the forms of soil P and the underlying response mechanisms with soil physical and chemical properties remain unclear.…”