Increased phosphorus availability to corn resulting from the simultaneous applications of phosphate rock, calcareous rock, and biochar to an acid sandy soil

• Published in: Pedosphere Vol. 30; no. 6; pp. 719 - 733
• Main Authors: RAFAEL, Rogério Borguete Alves, FERNÁNDEZ-MARCOS, Maria Luisa, COCCO, Stefania, RUELLO, Maria Letizia, FORNASIER, Flavio, CORTI, Giuseppe
• Format: Journal Article
• Language: English
• Published: Beijing Elsevier Ltd 01.12.2020; Elsevier Science Ltd; Department of Agriculture, Food and Environmental Sciences, Università Politecnica delle Marche, Ancona 60131 Italy%Department of Soil Science and Agricultural Chemistry, Universidad de Santiago de Compostela, Lugo 27002 Spain; Department of Rural Engineering, Faculty of Agronomy and Forestry Engineering, Universidade Eduardo Mondlane, Maputo 257 Mozambique; Instituto de Biodiversidade Agraria e Desenvolvemento Rural, Universidad de Santiago de Compostela, Lugo 27002 Spain%Department of Agriculture, Food and Environmental Sciences, Università Politecnica delle Marche, Ancona 60131 Italy%Department of Materials, Environmental Sciences and Urban Planning, Università Politecnica delle Marche, Ancona 60131 Italy%Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Centro di Ricerca per lo Studio delle Relazioni tra Pianta e Suolo (C.R.E.A.-R.P S.), Gorizia 34170 Italy
• Subjects: Acidic soils; Agricultural economics; Agricultural production; Arenosols; Availability; available P; Cation exchange; Cation exchanging; Charcoal; Corn; Crop production; Crop yield; enzyme activity; Exploitation; Fertilizers; Glucosidase; Organic carbon; Oxidation; Phosphate; phosphite oxidation; Phosphodiesterase; Phosphorus; Pyrolysis; Rocks; Sandy soils; Soil fertility; Soil investigations; Soil properties; Soil treatment; Synergistic effect; α-Glucosidase; Arenosols; available P; phosphite oxidation; soil fertility; enzyme activity
• ISSN: 1002-0160; 2210-5107
• DOI: 10.1016/S1002-0160(20)60034-0

Phosphorus (P) deficiency is one of the main constraints on crop production in Arenosols (acid sandy soil). The high cost of P fertilizers may represent an insurmountable obstacle in many poor countries, leaving the exploitation of their own calcareous and phosphate rocks as the only low-cost and long-term alternative. Biochar is suggested to have positive effects on soil properties; however, there is no published research on the synergistic effects of biochar and rocky materials in modifying soil properties. The aim of this study was to investigate the chemical and biochemical responses of an acid Arenosol treated with phosphate rock (PR), calcareous rock (CR), and biochar (BC), and the implications for corn yield. A soil from Marracuene District, Mozambique was used, where corn was grown for 90 d with the soil treated with: no addition (control), water-soluble zinc phosphite fertilizer (WSP), PR, WSP+CR, WSP+BC, WSP+CR+BC, PR+BC, and PR+CR+BC. Biochar was produced by pyrolysis of babycorn peels for 4 h at 450 °C and applied at 11 g kg−1. The soil pHH2O increased from about 4.54 in the control to 7.38 in the PR+CR+BC treatment. Easily oxidizable organic carbon, cation exchange capacity, and available P were higher in the treatments containing BC than in the control. The treatments containing CR and/or BC led to the highest activities of alkaline phosphomonoesterase, phosphodiesterase, and α-glucosidase, which increased P availability and gave the greatest biomass and yields. We suggest that biochar provides additional soluble P and supplies adsorption sites for phosphate, preventing its evolution to unavailable forms. Thus, PR applied together with BC contributed to an 840% yield increase compared to the control. The treatments containing WSP and BC facilitated phosphite oxidation to phosphate and increased crop yield.