TY - JOUR
T1 - Duckweed as an agricultural amendment
T2 - Nitrogen mineralization, leaching, and sorghum uptake
AU - Kreider, Andrew N.
AU - Fernandez Pulido, Carlos R.
AU - Bruns, Mary Ann
AU - Brennan, Rachel A.
N1 - Funding Information:
This material is based on work supported by the National Science Foundation (NSF) under Grant no. DGE1255832 (for A.N. Kreider). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of NSF. Support from the Penn State Sustainability Seed Grant Program is also gratefully acknowledged, as are the experimental design advice provided by Ray Bryant and Lou Saporito, and sample collection by Jonathan Caballero.
Funding Information:
Abbreviations: AASL, Agricultural Analytical Services Laboratory; CEC, cation exchange capacity; DAP, diammonium phosphate; DO, dissolved oxygen; NSF, National Science Foundation; ORP, oxidation reduction potential.
Publisher Copyright:
Copyright © American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2019/3/1
Y1 - 2019/3/1
N2 - Excessive N and P in surface waters can promote eutrophication (algae-dominated, low-O 2 waters), which decreases water quality and aquatic life. Duckweed (Lemnaceae), a floating aquatic plant, rapidly absorbs N and P from water and its composition shows strong potential as a soil amendment. Therefore, it may be used to transfer N and P from eutrophic water bodies to agricultural fields. In this work, dried duckweed was incorporated into agricultural soil in microcosm, column, and field tests to evaluate biological N cycling, nutrient retention, and crop yield compared with compost, diammonium phosphate (DAP), and an amendment-free control. In microcosm tests, 25 ± 13% of duckweed N was mineralized, providing on average less mineral N than DAP (107 ± 21%), but more than compost (11 ± 12%). In columns, duckweed treatments leached only 2% of the N added, significantly less than DAP, which leached 60% of its N. Compared with the control, DAP leached significantly more phosphate (78%), whereas duckweed and compost treatments leached less (56 and 27%, respectively). Crop yield, as well as runoff N and P, were measured in field tests growing forage sorghum [Sorghum bicolor (L.) Moench.]. Although less total N was applied to duckweed plots than to DAP plots (75 vs. 130 kg ha −1 , respectively), duckweed was found to retain 30% more total mineral N in a tilled agricultural field than DAP, while supporting a comparable yield. These tests indicate that duckweed may provide a sustainable source of N and P for agriculture.
AB - Excessive N and P in surface waters can promote eutrophication (algae-dominated, low-O 2 waters), which decreases water quality and aquatic life. Duckweed (Lemnaceae), a floating aquatic plant, rapidly absorbs N and P from water and its composition shows strong potential as a soil amendment. Therefore, it may be used to transfer N and P from eutrophic water bodies to agricultural fields. In this work, dried duckweed was incorporated into agricultural soil in microcosm, column, and field tests to evaluate biological N cycling, nutrient retention, and crop yield compared with compost, diammonium phosphate (DAP), and an amendment-free control. In microcosm tests, 25 ± 13% of duckweed N was mineralized, providing on average less mineral N than DAP (107 ± 21%), but more than compost (11 ± 12%). In columns, duckweed treatments leached only 2% of the N added, significantly less than DAP, which leached 60% of its N. Compared with the control, DAP leached significantly more phosphate (78%), whereas duckweed and compost treatments leached less (56 and 27%, respectively). Crop yield, as well as runoff N and P, were measured in field tests growing forage sorghum [Sorghum bicolor (L.) Moench.]. Although less total N was applied to duckweed plots than to DAP plots (75 vs. 130 kg ha −1 , respectively), duckweed was found to retain 30% more total mineral N in a tilled agricultural field than DAP, while supporting a comparable yield. These tests indicate that duckweed may provide a sustainable source of N and P for agriculture.
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U2 - 10.2134/jeq2018.05.0207
DO - 10.2134/jeq2018.05.0207
M3 - Article
C2 - 30951113
AN - SCOPUS:85063792595
VL - 48
SP - 469
EP - 475
JO - Journal of Environmental Quality
JF - Journal of Environmental Quality
SN - 0047-2425
IS - 2
ER -