Agronomy Journal • Volume 111, Issue 2 • 2019 1
T
he world food demand has increased because of popu-
lation growth and dietary changes. Brazil has approxi-
mately 60.1 million hectares of row crops with 227.9 Tg
of annual grain production (CONAB, 2017). It stands out as hav-
ing high agricultural potential with a good capacity to increase
grain production in future decades. A large portion of Brazil’s
grain production areas (60%) are managed using the NT system,
which provides land cover with continuous living or decaying veg-
etation for soil protection. In addition, NT is an option for food
production that is low cost, is easily applied to practical operations
in the field, and is more sustainable than conventional tillage
systems (Crusciol et al., 2012), due to the species used and residue
maintenance on the soil surface in no-till systems.
e success of an NT system depends on the knowledge of
the system as a whole. Knowledge of the characteristics of the
cover crops is important. For example, the amount and the qual-
ity of biomass influences the nutrient amount and release for use
by the succeeding crop during (or aſter) residue decomposition
(Crush et al., 2005; Boer et al., 2007; Garcia et al., 2008; Leite
et al., 2010; Soratto, 2011). Several authors have noted beneficial
effects from cover crops, resulting in enhanced biological activ-
ity and chemical and physical soil properties from the cover
crop, and improved yield of subsequent crops (Costa et al., 2014;
Boeni et al., 2014; Brandan et al., 2017).
Commonly used perennial forage species in the tropics, mainly
in Brazil, include those from the genus Urochloa; specifically,
these species have merits as a pasture grass for cropping systems,
crop–livestock systems, and crop–livestock–forest systems.
Perennial forage grasses enhance crop species diversification
(Siqueira et al., 2017) and provide a viable alternative for the
maintenance of NT systems (Timossi et al., 2007; Almeida et al.,
2017). Furthermore, the high potential DM production (Sereia
Impacts of Nitrogen Management on No-Till Maize Production
Following Forage Cover Crops
Letusa Momesso, Carlos A.C. Crusciol,* Rogério P. Soratto, Tony J. Vyn,
Katiuça S. Tanaka, Claudio H.M. Costa, Jayme Ferrari Neto, and Heitor Cantarella
Published in Agron. J. 111:1–11 (2019)
doi:10.2134/agronj2018.03.0201
Copyright © 2019 by the American Society of Agronomy
5585 Guilford Road, Madison, WI 53711 USA
All rights reserved
ABSTRACT
Crop residue decomposition is slower in no-till (NT) systems,
especially in high-biomass systems. Adopting optimum nN man-
agement can provide increased soil coverage and synchronize the
supply of nutrients with the period of highest crop demand in agro-
ecosystems. A three-year experiment was conducted to assess the
feasibility of applying N on forage grass cover crops before termina-
tion {Urochloa brizantha (Hochst. Ex A. Rich.) R.D. Webster [syn.
Brachiaria brizantha (Hochst. Ex A. Rich) Stapf] and Urochloa
ruziziensis (R. Germ. and C.M. Evrard) Crins [syn. B. ruzizien-
sis (R. Germ. and C.M. Evrard)]}, or on forage grass cover crop
residues immediately before maize (Zea mays L.) seeding, aiming
to supply N to the following maize crop. Urochloa brizantha had
25% higher biomass production and a higher amount of nutrient
content than U. ruziziensis. e N application before termination
increased biomass production and nutrient content in cover crop
residues compared with the conventional fertilization method (30
kg N ha
–1
in the maize seeeding plus 170 kg N ha
–1
sidedressed in
V
6
growth stage). Nitrogen applied one day before seeding (DBS)
of maize or using conventional method resulted in a higher number
of ears per plant and more kernels per ear as well as a higher grain
yields of maize (13.8 and 14.1 Mg ha
–1
, respectively) compared to
N applied on cover crops. Our results suggest that, while both for-
age grass cover crops produced greater amounts of dry matter (DM)
and released similar amounts of nutrients, applying all N to cover
crops before maize is not a feasible alternative. Nitrogen applica-
tion 1 DBS could be an alternative management option to supply
N to maize because this method resulted in similar nitrogen use
efficiency (NUE) as conventional fertilization method.
L. Momesso, São Paulo State Univ. (UNESP), College of
Agricultural Sciences, Botucatu, São Paulo, Brazil (current address,
Netherlands Institute of Ecology, Dep. of Microbial Ecology, 6708
PB, Wageningen, Netherlands); C.A.C. Crusciol, R.P. Soratto, K.S.
Tanaka, J. Ferrari Neto, São Paulo State Univ. (UNESP), College of
Agricultural Sciences, Dep. of Crop Science, Av. Universitária, 3780,
Lageado Experimental Farm, 18610-034 Botucatu, São Paulo, Brazil;
T.J. Vyn, Purdue Univ., Agronomy Dep., West Lafayette, IN, United
States; C.H.M. Costa, Federal Univ. of Goias (UFG), Agronomy
Dep., Jataí, Goiás, Brazil; H. Cantarella, Agronomic Institute of
Campinas (IAC), Soils and Environmental Resources Center,
Campinas, São Paulo, Brazil. Received 21 Mar. 2018. Accepted 19
Oct. 2018. *Corresponding author (carlos.crusciol@unesp.br).
Abbreviations: C, carbon; Ca, calcium; DAT, day aſter termination;
DBS, day before seeding; DM, dry matter; K, potassium; Mg,
magnesium; N, nitrogen; NUE, nitrogen use efficiency; NT, no-till;
P, phosphorus; SOM, soil organic matter; S, sulfur.
Core Ideas
• Urochloa brizantha as cover crop produced more biomass and nutri-
ent cycling than U. ruziziensis.
• Nitrogen fertilizer on Urochloa cover crops increased biomass pro-
duction but limited maize yield.
• e highest maize yields were obtained when N was applied on day
before seeding or under conventional method (N applied at seeding
plus sidedressing).
• All N applied on Urochloa residue prior to maize can be an option,
but is risky in regions of high rainfall.
CROP ECONOMICS, PRODUCTION, AND MANAGEMENT
Published online January 4, 2019