Long-term management strategies to optimize phosphorus utilization in a maize and succession

Author(s)

Gotz, Lenir Fatima ; Alves, Elton Eduardo Novais ; de Oliveira, Thamires Dutra Zancanaro ; Nunes, Rafael de Souza ; Condron, Leo Murtagh ; Vergutz, Leonardus ; Pavinato, Paulo Sergio

• Document type: Journal article
• Source: FIELD CROPS RESEARCH; v. 322, p. 7-pg., 2025-01-25.

Abstract

Context or problem: The efficiency of phosphorus (P) input utilization in Brazilian agricultural systems is low (50 %) but can be improved by adopting appropriate management strategies. Objective or research question: The objective of this study was to assess and quantify the combined long-term effects of soil tillage and rates and forms of P fertilizer inputs on soybean [Glycine max (L.) Merr.] and maize (Zea mays L.) yield, P use efficiency and soil P availability in a high P-fixing tropical soil. Methods: A comprehensive 22-year field experiment was undertaken in a Brazilian Cerrado soil with two soil tillage systems (conventional-CT and no-tillage-NT) combined with five P fertilizer management, being two sources of P [triple superphosphate (TSP) and Gafsa reactive phosphate rock (RPR)], under two annual rates of P (22 and 44 kg ha-1), and one control (no P application). Measurements included crop yield, removed P, partial P balance, and soil P [total P, legacy P, and labile P (Mehlich-3)]. Results: The NT and CT systems were equally productive. Plant yield responses were similar for TSP and RPR when 44 kg ha-1 of P was applied annually, although maize grain yield was 6 % higher for TSP compared with RPR at the lower rate of P application (22 kg ha-1 yr-1of P). The low P input rate was not enough to meet crop demand since the partial P balance was 131 % compared with 80 % for the high P input rate, both under TSP application. The same behavior was verified under RPR application, being 115 % compared with 74 % for the low and high rate of P, respectively. In the soil, CT system showed narrower differences between treatments, with a homogeneous distribution of P in depth compared with NT, while the NT system resulted in enhanced P accumulation in the topsoil, especially at the high rate of P fertilizer input. Conclusions: Our findings indicate that the use of an intermediate rate between 22 and 44 kg ha-1 yr-1 of P by RPR or TSP, especially under NT, is a recommended management strategy to optimize P utilization by maize and soybean while increase soil P bioavailability in a high P fixing tropical soil. Implications or significance: This study confirms that improving phosphate fertilization and soil management practices is key to ensuring the sustainable and efficient utilization of P in tropical agricultural systems. (AU)

• FAPESP's process: 20/09593-8 - Temporal variation in phosphorus dynamics under different soil management and phosphate fertilizers
• Grantee: Lenir Fátima Gotz
• Support Opportunities: Scholarships in Brazil - Doctorate