TY - JOUR

T1 - Legume nitrogen credits for sugarcane production

T2 - implications for soil N availability and ratoon yield

AU - Tenelli, Sarah

AU - Otto, Rafael

AU - de Castro, Saulo Augusto Quassi

AU - Sánchez, Camilo Ernesto Bohórquez

AU - Sattolo, Thales Meinl Schmiedt

AU - Kamogawa, Marcos Yassuo

AU - Pagliari, Paulo Humberto

AU - Carvalho, João Luís Nunes

N1 - Funding Information: Acknowledgements This project was funded by Fundac¸ão de Amparo à Pesquisa do Estado de São Paulo (FAPESP Process 2014/05591-0). R. Otto received a research productivity fellowship from the Brazilian National Council for Scientific and Technological Development (CNPq) (grant #308007/2016-6). To the sugarcane units Usina Quata, Usina Cerradinho and Usina Boa Vista for providing fields and operation support. Publisher Copyright: © 2019, Springer Nature B.V.

PY - 2019/4/15

Y1 - 2019/4/15

N2 - One of the steps needed to achieve sustainable bioenergy is to reduce our reliance on synthetic nitrogen (N). Despite the fact that legume cover crops have the potential to increase soil quality and sugarcane (Saccharum spp.) yield, much information is still needed to determine amount of N available from cover crops to sequential ratoon cycles. This study was designed to assess the impacts of sunn hemp (Crotalaria spectabilis) cover crop on soil N dynamics and sugarcane ratoon response to N fertilization during two harvest seasons across three contrasting soil and climatic conditions in southern Brazil. The treatments consisted of cover crop and fallow established prior to sugarcane replanting; in addition to three N-fertilizer rates 60, 120 and 180 kg N ha −1 and a 0-N control applied during the first and second ratoons. Although there was increased sugarcane yield (8–13 Mg ha −1 in first ratoon and 10–16 Mg ha −1 in second ratoon) in plots planted with cover crop, it was not possible to detect significant increases in soil inorganic N, microbial biomass C and Illinois Soil N Test content under cover crop compared with fallow. Cover crop with sunn hemp increased the accumulated two-year yields by 14–25 Mg ha −1 at all sites and NUE (Mg stalks kg −1  N) across all N rates at two sites. Our findings support the conclusion that cover crop did not change the N requirement of succeeding ratoon crops but increases the yield, thereby improving NUE in sugarcane systems.

AB - One of the steps needed to achieve sustainable bioenergy is to reduce our reliance on synthetic nitrogen (N). Despite the fact that legume cover crops have the potential to increase soil quality and sugarcane (Saccharum spp.) yield, much information is still needed to determine amount of N available from cover crops to sequential ratoon cycles. This study was designed to assess the impacts of sunn hemp (Crotalaria spectabilis) cover crop on soil N dynamics and sugarcane ratoon response to N fertilization during two harvest seasons across three contrasting soil and climatic conditions in southern Brazil. The treatments consisted of cover crop and fallow established prior to sugarcane replanting; in addition to three N-fertilizer rates 60, 120 and 180 kg N ha −1 and a 0-N control applied during the first and second ratoons. Although there was increased sugarcane yield (8–13 Mg ha −1 in first ratoon and 10–16 Mg ha −1 in second ratoon) in plots planted with cover crop, it was not possible to detect significant increases in soil inorganic N, microbial biomass C and Illinois Soil N Test content under cover crop compared with fallow. Cover crop with sunn hemp increased the accumulated two-year yields by 14–25 Mg ha −1 at all sites and NUE (Mg stalks kg −1  N) across all N rates at two sites. Our findings support the conclusion that cover crop did not change the N requirement of succeeding ratoon crops but increases the yield, thereby improving NUE in sugarcane systems.

KW - Biological N fixation

KW - Cover crop

KW - Crotalaria spectabilis

KW - Illinois soil nitrogen test

KW - Inorganic N

KW - Saccharum spp

UR - http://www.scopus.com/inward/record.url?scp=85062002635&partnerID=8YFLogxK

U2 - 10.1007/s10705-019-09979-y

DO - 10.1007/s10705-019-09979-y

M3 - Journal article

AN - SCOPUS:85062002635

VL - 113

SP - 307

EP - 322

JO - Nutrient Cycling in Agroecosystems

JF - Nutrient Cycling in Agroecosystems

SN - 1385-1314

IS - 3

ER -