Long term sugarcane straw removal affects soil phosphorus dynamics

Autor(es)

Soltangheisi, Amin ^{[1, 2]} ; Haygarth, Philip M. ^[2] ; Pavinato, Paulo Sergio ^[3] ; Cherubin, Mauricio Roberto ^[3] ; Bettoni Teles, Ana Paula ^[3] ; Bordonal, Ricardo de Oliveira ^[4] ; Nunes Carvalho, Joao Luis ^[4] ; Withers, Paul J. A. ^[2] ; Martinelli, Luiz Antonio ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Ctr Nucl Energy Agr, Isotop Ecol Lab, 303 Centenario Ave, BR-13416000 Piracicaba, SP - Brazil

^[2] Univ Lancaster, Lancaster Environm Ctr, Bailrigg LA1 4YQ - England

^[3] Univ Sao Paulo, Dept Ciencia Solo, Escola Super Agr Luiz de Queiroz ESALQ, Piracicaba - Brazil

^[4] Brazilian Ctr Energy & Mat Res CNPEM, Brazilian Biorenewables Natl Lab LNBR, Giuseppe Maximo Scolfaro St 10000, BR-13083100 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SOIL & TILLAGE RESEARCH; v. 208, APR 2021.
• Citações Web of Science: 0

Resumo

Brazil is the world's largest sugarcane producer. This crop leaves huge amounts of straw behind which have to be managed with innovative approaches. In this study, a field experiment was carried out over six successive years of sugarcane harvests to evaluate the effect of straw maintenance on the field on changes in soil phosphorus (P) fractions. Four straw maintenance rates were tested: (i) maintaining 15 Mg ha-1 (SM15); (ii) maintaining 10 Mg ha-1 (SM10); (iii) maintaining 5 Mg ha-1 (SM5), and (iv) maintaining 0 Mg ha-1 (SM0). Our results showed that low maintenance of straw (SM5) resulted in the highest amount of P extracted by anion exchange resin and inorganic P extracted by 0.5 mol L-1 NaHCO3 in 0-5 and 5-10 cm soil depths. While total removal of residues resulted in soil P deficiency after six crop cycles, keeping straw on the soil surface at the rate of 5 Mg ha-1 supports plant growth without the need for P fertilizer application. We detected inorganic P extracted by 0.1 mol L-1 NaOH as the sink of P derived from straw since it was the only P fraction which increased with increasing straw on the soil surface. Non-labile P fractions were not influenced by straw maintenance rates in all depths. This is a promising result since it shows that P derived from straw does not accumulate in non-labile P fractions which are not plant available. Inorganic P was not influenced by straw removal rates and total P was only changed in 0-5 cm soil layer, while organic P was affected in all depths. We observed that organic P is available to sugarcane plants under SM0, SM5, and SM10, while under SM15, organic P does not play a role in sugarcane nutrition. <comment>Superscript/Subscript Available</comment (AU)

• Processo FAPESP: 17/11332-5 - Dinâmica do fósforo e suas frações em solos sob conversão pastagem-cana e intensificação de pastagens
• Beneficiário: Amin Soltangheisi
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 19/21532-7 - Mudança de fósforo orgânico influenciada pela mudança de uso da terra no Brasil
• Beneficiário: Amin Soltangheisi
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado