Application of biosolid for berseem clover fertilization: Fodder characteristics and health risk assessment

Ivan Širic1, Sadeq K. Alhag2, Eman A. Al-Shahari2, ?eljko Andabaka1, Pankaj Kumar3, 4*, Sami Abou Fayssal5, 6, Bashir Adelodun7, 8, and Ebrahem M. Eid9
Finding sustainable methods for utilizing biosolids, also known as municipal sewage sludge (SS), presents a pressing challenge in modern waste management practices. Therefore, this study aimed to evaluate the impact of SS amendment on growth, biochemical, proximate, and heavy metal bioaccumulation parameters of berseem clover (Trifolium alexandrinum L.) fodder crop under field conditions. Trifolium alexandrinum was cultivated using different rates of SS mixing (i.e., T0: 0% as control with no SS application, T1: 5%, and T2: 10%). The results obtained showed a significant (p < 0.05) increment in growth, biochemical, and proximate parameters of T. alexandrinum with an increasing SS mixing rate. The highest productivity of T. alexandrinum fodder (1.92 kg m-2 fw) was observed in the T2 treatment as compared to the control treatment. The heavy metal analysis of shoot and root parts of T. alexandrinum showed that the contents (mg kg-1) of eight elements (Cd 0.02-0.13, Co 0.04-0.08, Cu 5.94-0.05, Cr 0.43-1.68, Fe 7.08-15.93, Ni 0.89-2.90, Mn 1.62-5.38, and Zn 3.30-7.04) increased significantly (p < 0.05) with SS mixing rate. The bioaccumulation factor (BAF) was below 1 except for Cu and Zn exhibiting their rapid uptake by plants from SS-treated soils. However, dietary intake modeling (DIM < 1) and health risk index (HRI < 1) studies showed that the levels of heavy metals did not exceed the permissible limits in any SS treatment. Overall, SS amendment has a positive impact on the growth, biochemical, proximate, and heavy metal characteristics of T. alexandrinum. Therefore, this study suggested a strategy for low-cost soil fertilization and fodder crop production which could sustainably benefit waste recycling.
Keywords: Bioaccumulation, health risk studies, sewage sludge, soil fertilization, waste management.
1University of Zagreb, Faculty of Agriculture, Svetosimunska 25, 10000 Zagreb, Croatia.2 King Khalid University, College of Science and Arts, Biology Department, Muhayl Asser 61913, Saudi Arabia.3Gurukula Kangri, Department of Zoology and Environmental Science, Haridwar 249404, India.4Society for AgroEnvironmental Sustainability, Research and Development Division, Dehradun 248007, India.5University of Forestry, Faculty of Agronomy, Department of Agronomy, 1797 Sofia, Bulgaria.6Lebanese University, Faculty of Agriculture, Department of Plant Production, Beirut 1302, Lebanon.7University of Ilorin, Department of Agricultural and Biosystems Engineering, Ilorin 240103, Nigeria.8Kyungpook National University, Department of Agricultural Civil Engineering, Daegu 41566, Republic of Korea.9Kafrelsheikh University, Faculty of Science, Botany Department, Kafr El-Sheikh 33516, Egypt.*Corresponding author (kumarpankajgkv@gmail.com).