TY - JOUR
T1 - Managing cover crop C:N ratio and subsurface-banded poultry litter rate for optimal corn yields
AU - Mirsky, Steven B.
AU - Davis, Brian W.
AU - Poffenbarger, Hanna
AU - Cavigelli, Michel A.
AU - Maul, Jude E.
AU - Schomberg, Harry
AU - Spargo, John T.
AU - Thapa, Resham
N1 - Publisher Copyright:
© 2023 The Authors. Agronomy Journal © 2023 American Society of Agronomy.
PY - 2023/7/1
Y1 - 2023/7/1
N2 - Cover crops can be used to provide some of the nitrogen (N) needs of a cash crop to complement mineral fertilizers or manure, but there has yet been limited work to describe corn (Zea mays L.) yield as a function of cover crop quality and N inputs. We investigated the response of corn yield to gradients of both preceding cover crop C:N ratio and poultry litter (PL) application rates in Beltsville, MD during 2012–2014. To achieve different C:N ratios of the cover crops, hairy vetch (Vicia villosa Roth. "Groff") and cereal rye (Secale cereale L. "Aroostook") were seeded in a replacement series of six seeding rate proportions, resulting in shoot C:N ratios of 9.2:1 to 152:1 across years. For each hairy vetch/cereal rye sown proportions, PL was side-dressed at corn V5–V8 stage in subsurface bands (SSB) at four targeted rates: Zero, P-based (67 kg plant available nitrogen [PAN] ha−1), N-based (135 kg PAN ha−1), and excess N and P (269 kg PAN ha−1). We found that corn yield followed a linear-plateau relationship across these two dimensions. Within the linear region, each unit increase in log-scaled cover crop C:N ratio resulted in a yield decrease of 2.56 ± 0.26 Mg ha−1 at a given rate of SSB PL. To optimize corn yields, we describe a model where each unit increase in log-scaled cover crop C:N ratio required an additional 45.9 ± 6.22 kg PAN ha−1 from SSB PL. Yields following winter fallow were typically intermediate to the range of yields observed following the gradient of cover crop C:N ratios. We did not find significant differences in corn yield responses when comparing SSB PL to at-planting incorporated or broadcast PL; we also found no significant differences between SSB PL and surface-banded urea ammonium nitrate. Taken together, our approach of modeling yield response across two dimensions can be widely used to guide adaptive N management in subsequent cash crops following winter cover crops, thereby balancing both economic and environmental objectives in cover crop-based cropping systems.
AB - Cover crops can be used to provide some of the nitrogen (N) needs of a cash crop to complement mineral fertilizers or manure, but there has yet been limited work to describe corn (Zea mays L.) yield as a function of cover crop quality and N inputs. We investigated the response of corn yield to gradients of both preceding cover crop C:N ratio and poultry litter (PL) application rates in Beltsville, MD during 2012–2014. To achieve different C:N ratios of the cover crops, hairy vetch (Vicia villosa Roth. "Groff") and cereal rye (Secale cereale L. "Aroostook") were seeded in a replacement series of six seeding rate proportions, resulting in shoot C:N ratios of 9.2:1 to 152:1 across years. For each hairy vetch/cereal rye sown proportions, PL was side-dressed at corn V5–V8 stage in subsurface bands (SSB) at four targeted rates: Zero, P-based (67 kg plant available nitrogen [PAN] ha−1), N-based (135 kg PAN ha−1), and excess N and P (269 kg PAN ha−1). We found that corn yield followed a linear-plateau relationship across these two dimensions. Within the linear region, each unit increase in log-scaled cover crop C:N ratio resulted in a yield decrease of 2.56 ± 0.26 Mg ha−1 at a given rate of SSB PL. To optimize corn yields, we describe a model where each unit increase in log-scaled cover crop C:N ratio required an additional 45.9 ± 6.22 kg PAN ha−1 from SSB PL. Yields following winter fallow were typically intermediate to the range of yields observed following the gradient of cover crop C:N ratios. We did not find significant differences in corn yield responses when comparing SSB PL to at-planting incorporated or broadcast PL; we also found no significant differences between SSB PL and surface-banded urea ammonium nitrate. Taken together, our approach of modeling yield response across two dimensions can be widely used to guide adaptive N management in subsequent cash crops following winter cover crops, thereby balancing both economic and environmental objectives in cover crop-based cropping systems.
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U2 - 10.1002/agj2.21369
DO - 10.1002/agj2.21369
M3 - Article
AN - SCOPUS:85162723261
SN - 0002-1962
VL - 115
SP - 1746
EP - 1761
JO - Agronomy Journal
JF - Agronomy Journal
IS - 4
ER -