Nitrogen Release Dynamics and Decomposition of Buried and Surface Cover Crop Residues. (1st July 2016)

• Record Type: Journal Article
• Authors: Jahanzad, E.; Barker, A. V.; Hashemi, M.; Eaton, T.; Sadeghpour, A.; Weis, S. A.
• Is Part Of: Agronomy Journal. Volume 108:Number 4(2016)
• Page Start: 1735
• Page End: 1741
• Publication Date: 2016-07-01
• Subjects: Agronomy -- Periodicals; 630
• DOI: 10.2134/agronj2016.01.0001
• Languages: English
• ISSNs: 0002-1962

Abstract

Abstract : Integrating cover crops into farming systems may contribute to meeting N demands of succeeding crops and therefore decrease fertilization and environmental concerns. To study the trend of released N in buried (BR) and surface residues (SR) of three different cover crops a 2‐yr field experiment was conducted in a randomized complete block design on a fine sandy loam. Forage radish ( Raphanus sativus L.) and winter pea ( Pisum sativum subsp. arvense L.) decomposition rate and N release trend were compared with cereal rye ( Secale cereale L.), as the conventionally grown cover crop in Massachusetts, to evaluate if forage radish or winter pea would provide more N for early planted crops in the spring than cereal rye. Forage radish produced the highest dry matter yield (3.46 Mg ha −1 ) followed by winter pea (3.1 Mg ha −1 ) and cereal rye (2.42 Mg ha −1 ). All of the cover crops had a faster residue decomposition and release of N when buried in the soil. Through the decomposition period, forage radish and winter pea lost their initial biomass and N concentration faster than cereal rye in both BR and SR due to higher C/N ratio and lignin concentration in rye. Our results showed a greater potential of forage radish or winter pea for a synchronous N release relative to crop N demands early in the spring than with cereal rye. Core Ideas Forage radish has great potential for synchronous N release with cash crop N demands early in the spring. A high N yielding winterkilled cover crop is preferred over rye if early planting of cash crop is target. Rye may not provide the succeeding crop with sufficient N when terminated early.