Recycling of silicon-rich agro-wastes by their combined application with phosphate solubilizing microbe to solubilize the native soil phosphorus in a sub-tropical Alfisol. (15th September 2022)

• Record Type: Journal Article
• Authors: Alam, Khurshid; Biswas, Dipak Ranjan; Bhattacharyya, Ranjan; Das, Debarup; Suman, Archna; Das, Tapas Kumar; Paul, Ranjit Kumar; Ghosh, Avijit; Sarkar, Abhijit; Kumar, Rajesh; Chawla, Gautam
• Is Part Of: Journal of environmental management. Volume 318(2022)
• Publication Date: 2022-09-15
• Subjects: Si-rich agro-wastes -- P fractionation -- P and Si release Kinetics -- Native soil P solubilization -- Phosphate solubilizing microorganism; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2022.115559
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: It is imperative to find suitable strategies to utilize the native soil phosphorus (P), as natural rock phosphate deposits are at a verge of depletion. We explored two such cost-effective and eco-friendly strategies for native soil P solubilization: silicon (Si)-rich agro-wastes (as Si source) and phosphate solubilizing microorganism (PSM). An incubation study was conducted in a sub-tropical Alfisol for 90 days at 25 °C under field capacity moisture. A factorial completely randomized design with 3 factors, namely: Si sources (three levels: sugarcane bagasse ash, rice husk ash, and corn cob ash), PSM (two levels: without PSM, and with PSM); and Si doses [three levels: no Si (Si0 ), 125 (Si125 ) and 250 (Si250 ) mg Si kg −1 soil] was followed. The PSM increased solution P and soluble Si level by ∼22.2 and 1.88%, respectively, over no PSM; whereas, Si125 and Si250 increased solution P by ∼60.4 and 77.1%, as well as soluble Si by ∼41.5 and 55.5%, respectively, over Si0 . Also, interaction of PSM × Si doses was found significant ( P<0.05 ). Activities of soil enzymes (dehydrogenase, acid phosphatase) and microbial biomass P also increased significantly both with PSM and Si application. Overall, PSM solubilized ∼4.18 mg kg −1 of inorganic P and mineralized ∼5.92 mg kg −1 of organic P; whereas, Si125 and Si250 solubilized ∼3.85 and 5.72 mg kg −1 of inorganic P, and mineralized ∼4.15 and 5.37 mg kg −1 of organic P, respectively. Path analysis revealed that inorganic P majorly contributed to total P solubilization; whereas, soluble and loosely bound, iron bound and aluminium bound P significantly influenced the inorganic P solubilization. Thus, utilization of such wastes as Si sources will not only complement the costly P fertilizers, but also address the waste disposal issue in a sustainable manner. Highlights: Impact of Si-rich ashes and PSM on native soil P solubilization was studied. Interaction of PSM × Si doses was positive in mediating cumulative P and Si release. Both PSM and applied Si significantly increased soil enzymes' activities and MBP. Si@125 and 250 mg kg −1 solubilized ∼8.01 and 11.1 mg kg −1 of soil P, respectively. Fe and Al bound P fractions primarily contributed to total P solubilization.