Effect of previous soil management on sugarcane response to nitrogen fertilization

Autor(es)

Otto, Rafael ; Mariano, Eduardo ; Mulvaney, Richard Lesley ; Khan, Saeed Ahmad ; Boschiero, Beata Nastaro ; Tenelli, Sarah ; Ocheuze Trivelin, Paulo Cezar

• Tipo de documento: Artigo Científico
• Fonte: CIENTIA AGRICOL; v. 76, n. 1, p. 10-pg., 2019-01-01.

Resumo

N Fertilizer recommendations must be improved to optimize N use efficiency (NUE) for bioenergy crops. A study was conducted to test the hypothesis that sites varying in historical usage of by-product differ in soil N-supplying power and sugarcane (Saccharum spp.) responsiveness to N fertilization. Our aim was to quantify soil N availability and N fertilizer rates, sources, and application timings for their effects on sugarcane yield and NUE. Three N response trials, each involving 0 to 200 kg N ha(-1), were conducted in the state of Sao Paulo, Brazil, at sites varying historically in the usage of vinasse. Before fertilizer application and at harvest, soil inorganic N content was quantified and potential N mineralization estimated by the Illinois Soil Nitrogen Test (ISNT); stalk yield and sugar content were measured at harvest and used to estimate NUE. Sugarcane showed significant response to N fertilization only at the sites with no history of vinasse usage. Reducing the N rate from 120 to 80 kg N ha(-1) showed limited potential for lowering yield (similar to 1 %), while increasing the NUE by 54 %, which was far better than the 14 % increase achieved by modifying the N source or application timing. Monitoring inorganic N and ISNT levels over time to estimate soil N-supplying power has potential for predicting the responsiveness of sugarcane to N fertilization; however, ISNT interpretations must consider factors that impede mineralization or crop N utilization, such as soil acidity or a limitation on the availability of Ca or P. Soil N testing can help optimize NUE for sustainable bioenergy production. (AU)

• Processo FAPESP: 11/22660-7 - Avanços metodológicos no estudo das transformações do nitrogênio do solo para a produção de cana-de-açúcar
• Beneficiário: Rafael Otto
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado