LAUSR

In Brazilian sugarcane (Saccharum spp.) production systems, the practice of moving harvesting residue from row to inter-row positions (i.e., raking) has increased in response to producer concerns over the potential negative effects of sugarcane straw on crop establishment and stalk yield. Despite increasing adoption among sugarcane farmers, the impacts of straw raking practices on plant growth and yield remain unclear. A 2-yr experiment that included both dry and wet seasons was conducted at two sites in southeastern Brazil to evaluate straw management strategy effects on plant tillering, phytomass accumulation, plant nutritional status, and stalk yield. The experiments were established at the Bom Retiro mill and the Univalem mill. Experimental treatments included raking straw to inter-rows (raked), total straw removal (bare soil), and no straw removal (straw cover). Raked and bare soil treatments improved plant tillering but did not influence final plant population. Straw management had a slight effect on phytomass accumulation. Reduction of phytomass yield was observed from the first to the second ratoon during both seasons at both sites. At Bom Retiro, phytomass yield decreased 37% for stands established during the dry season and 19% for stands established during the wet season. At Univalem, phytomass yield decreased 20% for stands established during the dry season and 30% for stands established during the wet season. Retaining straw in the field (regardless of treatment) increased leaf tissue P content but not stalk yield. Raking straw from row to interrow positions at these locations in southeastern Brazil had no benefit on sugarcane yield but may result in soil compaction and higher production costs over time. I.P. Lisboa, M.R. Cherubin, M.R. Gmach, E.F.F. Junior, and C.E.P. Cerri, Univ. of São Paulo, “Luiz de Queiroz” College of Agriculture, 11 Pádua Dias Ave., Piracicaba, São Paulo 13418-900, Brazil; R.P. de Lima, Dep. of Agricultural Engineering, Federal Rural Univ. of Pernambuco, s/n Dom Manuel Medeiros St., Recife, Pernambuco 52171-900, Brazil; B.J. Wienhold, M.R. Schmer, and V.L. Jin, Agroecosystem Management Research Unit, USDA-ARS, 251 Filley Hall/Food Ind. Complex, Univ. of Nebraska–Lincoln, East Campus, Lincoln, NE 68583; H.P. Guerra and C.C. Cerri, Univ. of São Paulo, Center for Nuclear Energy in Agriculture, 303 Centenário Ave., Piracicaba, São Paulo 13400970, Brazil. This article is in memoriam of Professor Carlos C. Cerri. Received 30 July 2018. Accepted 28 Mar. 2019. *Corresponding author ([email protected], [email protected]). Assigned to Associate Editor Fernando Miguez. Abbreviations: DAH, days after harvesting; LAI, leaf area index. Published in Crop Sci. 59:1732–1744 (2019). doi: 10.2135/cropsci2018.07.0468 © 2019 The Author(s). Re-use requires permission from the publisher. Published May 16, 2019