Revealing soil legacy phosphorus to promote sustainable agriculture in Brazil

Author(s)

Pavinato, Paulo S. ^[1] ; Cherubin, Mauricio R. ^[1] ; Soltangheisi, Amin ^[1] ; Rocha, Gustavo C. ^[1] ; Chadwick, Dave R. ^[2] ; Jones, Davey L. ^[2]

Affiliation

^[1] Univ Sao Paulo, ESALQ, Coll Agr Luiz Queiroz, Av Padua Dias 11, BR-13418900 Piracicaba, SP - Brazil

^[2] Bangor Univ, Sch Nat Sci, Bangor LL57 2UW, Gwynedd - Wales

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 10, n. 1 SEP 24 2020.
• Web of Science Citations: 7

Abstract

Exploiting native soil phosphorus (P) and the large reservoirs of residual P accumulated over decades of cultivation, namely ``legacy P{''}, has great potential to overcome the high demand of P fertilisers in Brazilian cropping systems. Long-term field experiments have shown that a large proportion (> 70%) of the surplus P added via fertilisers remains in the soil, mainly in forms not readily available to crops. An important issue is if the amount of legacy P mobilized from soil is sufficient for the crop nutritional demand and over how long this stored soil P can be effectively `mined' by crops in a profitable way. Here we mapped the spatial-temporal distribution of legacy P over the past 50 years, and discussed possible agricultural practices that could increase soil legacy P usage by plants in Brazil. Mineral fertiliser and manure applications have resulted in similar to 33.4 Tg of legacy P accumulated in the agricultural soils from 1967 to 2016, with a current annual surplus rate of 1.6 Tg. Following this same rate, soil legacy P may reach up to 106.5 Tg by 2050. Agricultural management practices to enhance soil legacy P usage by crops includes increasing soil pH by liming, crop rotation, double-cropping, inter-season cover crops, no-tillage system and use of modern fertilisers, in addition to more efficient crop varieties and inoculation with P solubilising microorganisms. The adoption of these practices could increase the use efficiency of P, substantially reducing the new input of fertilisers and thus save up to 31.8 Tg of P fertiliser use (US\$ 20.8 billion) in the coming decades. Therefore, exploring soil legacy P is imperative to reduce the demand for mineral fertilisers while promoting long-term P sustainability in Brazil. (AU)

• FAPESP's process: 17/04186-2 - Soil phosphorus balance and potential legacy phosphorus exploitation in Brazilian crop and livestock production systems
• Grantee: Paulo Sergio Pavinato
• Support Opportunities: Scholarships abroad - Research