Abstract
ABSTRACT The recent approach of eliminating the usage of fire for sugarcane harvesting resulted in managing the crop on a trashblanketed soil, to which a proper recommendation of N fertilization is lacking, a problem that remains in the coastal tablelands of the Espirito Santo State, Brazil. This study aimed at evaluating the effect of increasing N rates on stalk and sugar yields and the N use efficiency by the crop. The experimental area planted with sugarcane, at the first ratoon, is located in Linhares, Espirito Santo State. The treatments consisted of N rates varying from 80 to 160 kg N∙ha−1 as ammonium sulphate, and a control without N, in a completely randomized blocks experimental design. Stalk yield increased with the N rate, and fitting the results to a quadratic function suggests no response to fertilizer rates above 130 kg N∙ha−1. The highest margin of agricultural contribution was obtained at the rate of 100 kg N∙ha−1. The N use efficiency decreased from almost 49 to 38%, when the N rate increased from 100 to 160 kg N∙ha−1. There was no effect of increasing N rates on the sugar concentration, although the sugar yield response was positive and strongly influenced by the stalk production. Results showed the importance of reassessing the adequate N rate for maximizing yield in green cane production systems.
Highlights
In 2014, the area of sugarcane production in Brazil was close to 10 million hectares (IBGE 2016), and about 65% of this area was harvested without previous burning (INPE 2014)
The application of 70 kg N∙ha−1 as ammonium sulfate to a second ratton of sugarcane resulted in greater stalk yield (76 Mg∙ha−1) than when urea was the N fertilizer source (57 Mg∙ha−1), since the latter resulted in ammonia volatilization losses of 46% of the N applied (Vitti et al 2007)
The quadratic response found in this study indicates that a stalk production of 102 Mg∙ha−1 was the maximum attainable for the prevailing conditions, which corresponded to an N fertilization rate of 130 kg N∙ha−1 using ammonium sulfate (Figure 2)
Summary
In 2014, the area of sugarcane production in Brazil was close to 10 million hectares (IBGE 2016), and about 65% of this area was harvested without previous burning (INPE 2014). Its application on the trash blanketed may induce high N losses by NH3 volatilization (Costa et al 2003; Cantarella et al 2007),and cane yield may be negatively affected (Costa et al 2003). The application of 70 kg N∙ha−1 as ammonium sulfate to a second ratton of sugarcane resulted in greater stalk yield (76 Mg∙ha−1) than when urea was the N fertilizer source (57 Mg∙ha−1), since the latter resulted in ammonia volatilization losses of 46% of the N applied (Vitti et al 2007). The N losses associated to urea may explain the lowest levels of NUE quantified for sugarcane crop, mainly when the crop is managed without burning for harvest (Vieira-Megda et al 2015)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
