Author
POFFENBARGER, HANNA - Iowa State University | |
MIRSKY, STEVEN | |
KRAMER, MATTHEW | |
WEIL, RAYMOND - University Of Maryland | |
MEISINGER, JOHN | |
CAVIGELLI, MICHEL | |
SPARGO, JOHN - Pennsylvania State University |
Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/29/2015 Publication Date: 12/11/2015 Citation: Poffenbarger, H.J., Mirsky, S.B., Kramer, M.H., Weil, R.R., Meisinger, J.J., Cavigelli, M.A., Spargo, J.T. 2015. Cover crop and poultry litter management influence spatiotemporal availability of topsoil nitrogen. Soil Science Society of America Journal. 79:1660-1673. Interpretive Summary: Legume cover crops and animal manures are commonly used in crop production systems to supply nitrogen (N) while building soil health. To improve their use efficiency, legume cover crops are often utilized in a no-till crop production application, or combined with grass cover crops to slow their decomposition and get better synchrony between nitrogen release and crop N uptake. In the case of animal manures, improved N use efficiency can be achieved through incorporation or delaying application to a later crop growth stage (e.g., sidedress application in corn). Lastly, it is common to integrate cover crops with animal manures to ensure adequate crop fertility. To better understand how these practices influence N availability, we conducted a two-year experiment that included three cover crop residues: hairy vetch (Vicia villosa Roth), cereal rye (Secale cereale L.), and a hairy vetch/cereal rye mixture; and four poultry litter (PL) treatments: no PL and 3.5 Mg PL ha-1 applied either pre-plant broadcast, subsurface banded at the corn fifth-leaf stage, or pre-plant broadcast with tillage. Most of the available N in the broadcast treatment was concentrated near the soil surface, while available N associated with the subsurface band remained within 10 cm of the delivery location throughout the growing season, and to 20 cm in the incorporated treatment. Average available N to 30 cm was significantly greater in the hairy vetch residue than in the cereal rye residue at emergence and the fifth-leaf stage, while the cover crop mixture had average available N levels intermediate between the monocultures or similar to cereal rye depending on the year. In both years, corn N uptake tended to be greatest with hairy vetch residues and broadcast or subsurface banded PPL, averaging 215 kg ha-1 across years in these treatments. This work will help define soil sampling procedures for soil test labs when working with spatially localized manure application methods. Furthermore, our work provides a comprehensive understanding of N cycling for scientists in integrated cover crop and animal manure-based fertility programs, under a suit of different soil management and fertilizer application timing and placement methods. State extension specialists can use this information to inform farmer fertilizer management programs. Technical Abstract: Green and animal manures provide plant-available nitrogen (N) in annual cropping systems and contribute to improved soil quality. Our objectives were to determine the effects of cover crop residue type and pelletized poultry litter (PPL) application method on: 1) the spatiotemporal distribution of soil mineral N (Nmin), 2) the average topsoil Nmin at four developmental stages of corn (Zea mays L.), and 3) corn N uptake. Soil cores and plant samples were collected in a factorial experiment that included three cover crop residues: hairy vetch (Vicia villosa Roth), cereal rye (Secale cereale L.), and a hairy vetch/cereal rye mixture; and four PPL treatments: no PPL and 3.5 Mg PPL ha-1 applied either pre-plant broadcast, subsurface banded at the corn fifth-leaf stage, or pre-plant broadcast with tillage. Most of the Nmin in the broadcast treatment was concentrated near the soil surface, Nmin associated with the subsurface band remained within 10 cm of the delivery location throughout the growing season, while Nmin was distributed to a depth of 20 cm in the incorporated treatment. Average Nmin to 30 cm was significantly greater in the hairy vetch residue than in the cereal rye residue at emergence and the fifth-leaf stage, while the cover crop mixture had average Nmin levels intermediate between the monocultures or similar to cereal rye depending on the year. In both years, corn N uptake tended to be greatest with hairy vetch residues and broadcast or subsurface banded PPL, averaging 215 kg ha-1 across years in these treatments. |