| Texto completo | |
| Autor(es): |
Popin, Gustavo V.
[1]
;
Santos, Arthur K. B.
[1]
;
Melo, Paul L. A.
[2]
;
Cherubin, Mauricio R.
[1]
;
Cerri, Carlos E. P.
[1]
;
Siqueira-Neto, Marcos
[2]
Número total de Autores: 6
|
| Afiliação do(s) autor(es): | [1] Univ Sao Paulo, Coll Agr Luiz de Queiroz, Ave Padua Dias 11, BR-13400970 Piracicaba, SP - Brazil
[2] Univ Sao Paulo, Ctr Nucl Energy Agr, Ave Centenario 303, POB 96, BR-13400970 Piracicaba, SP - Brazil
Número total de Afiliações: 2
|
| Tipo de documento: | Artigo Científico |
| Fonte: | SOIL RESEARCH; v. 59, n. 2, p. 119-129, 2021. |
| Citações Web of Science: | 0 |
| Resumo | |
Sugarcane straw is a potential feedstock to increase bioenergy production. However, leaving straw on the soil surface is important to sustaining soil organic matter (SOM). We conducted a field experiment to evaluate the impacts of two years of straw removal on SOM in a sugarcane area - on an Eutric Nitisol in south-eastern Brazil - with low straw production (7 Mg ha(-1)). The experiment was a randomised complete block design (four blocks) with four rates of straw removal: (i) no removal, (ii) medium removal, (iii) high removal and (iv) total removal. We evaluated straw decomposition, soil carbon (C) and nitrogen (N) stock (0-30 cm), labile C, and microbial biomass C and N (0-10 cm). Increases in the straw removal rates reduced decomposition, with 30-42% of the initial straw amount remaining on the soil after one year (first year) and 33-38% remaining at the end of the second year. During the first year, no effect was found on soil C (8 kg m(-2)) and N (0.7 kg m(-2)) stocks; however, during the second year, total straw removal reduced soil C stock by 10% (0-30 cm) compared with no straw removal. Straw removal rates negatively affected the labile C (6-10% and 20-25%, first and second year respectively) and microbial C (correspondingly 10-15% and 21-27%). Microbial N was not altered in the first year, but decreased 26% due to straw maintenance (no removal) during the second year. Total straw removal decreased the C management index (CMI) by 15% (first year) compared with no straw removal. However, during the second year, all rates of straw removal decreased the CMI: by 15% for medium, 22% for high and 26% for total removal. Our findings indicate that any straw removal in areas with low straw production negatively affects SOM, initially through reduction in labile C pools. Although slight impacts on soil C and N stock were detected, reduction in straw-derived inputs stimulates microbial utilisation of soil C pools, and consequently reduces SOM over time. (AU) | |
| Processo FAPESP: | 18/09845-7 - Implicações da expansão e intensificação do cultivo da cana-de-açúcar nos serviços ecossistêmicos do solo |
| Beneficiário: | Maurício Roberto Cherubin |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |