Nitrogen use efficiency and grain yield of corn hybrids as affected by nitrogen rates and sowing dates in subtropical environment

Antonio Eduardo Coelho,Marcos Cardoso Martins,Hugo François Kuneski,Alvadi Antonio Balbinot,Luis Sangoi

doi:10.36783/18069657rbcs20210087

Abstract

Delay of sowing date in subtropical environments with long growing seasons can modify the yield response of corn hybrids to nitrogen (N) fertilization. This study evaluated the effects of the sowing time, and N top-dress rate on corn hybrids’ yield and N-use efficiency with different cycles. Two field experiments were carried out in subtropical environment of southern Brazil. The following factors were investigated: corn hybrids (AG9025, super early cycle and P30F53, early cycle), sowing times (early and late spring), [...]

Highlights

In southern Brazil, there has been an intense replacement of the first corn crop by soybean due to the adequate availability of technologies, market prices and liquidity of the oleaginous (Cattelan and Dall’Agnol, 2018)
The photoperiod on the day of harvest in Lages was 11:53, 10:57, 11:42, and 10:57 for AG9025 sown in early spring, AG9025 sown in late spring, P30F53 sown in early spring and P30F53 sown in late spring, respectively
The photoperiods on the harvest day in Atalanta were 12:18, 11:04, 12:18 and 10:55 h for AG9025 sown in early spring, AG9025 sown in late spring, P30F53 sown in early spring and P30F53 sown in late spring, respectively

Summary

Introduction

In southern Brazil, there has been an intense replacement of the first corn crop by soybean due to the adequate availability of technologies, market prices and liquidity of the oleaginous (Cattelan and Dall’Agnol, 2018). The first corn crop area in Brazil decreased from 9.8 million ha in 1999/2000 to 4.2 million ha in the 2019/2020 growing season (Conab, 2020). One of the factors that limits the economic viability of first corn crop in southern Brazil is its low yield. In the 2018/2019 growing season, the Brazilian average productivity of first corn crop was only 8.2 Mg ha-1 (Conab, 2020). The generation of information that allows better understanding of management practices for high corn grain yield is fundamental to enhance the cereal-cultivated first crop area, enabling rotation with soybean in spring/summer and increasing the sustainability and resilience of grain production systems in southern Brazil

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Discussion

Conclusion