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Influence of Controlled Drainage and Liquid Dairy Manure Application on Phosphorus Leaching from Intact Soil Cores
Author(s) -
Young Eric O.,
Geibel Justin R.,
Ross Donald S.
Publication year - 2017
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2016.04.0158
Subject(s) - leachate , drainage , manure , leaching (pedology) , chemistry , liquid manure , zoology , phosphorus , tile drainage , environmental chemistry , soil water , environmental science , agronomy , soil science , ecology , biology , organic chemistry
Controlled drainage can reduce nitrate export from tile drainage flow, but its impact on phosphorus (P) loss is largely unknown. We compared P leaching from soil cores treated as free drainage (FD) or controlled drainage (CD) before and after manure application. In August 2012, 16 intact cores (45 cm long, 15 cm diameter) were collected from a grass forage field ( Mollic Endoaquept ) located in Chazy, NY, and modified for drainage control and sampling. In Experiment 1 (no manure), initial leachate was defined as FD, and leachate collected 21 d later (valves closed) was considered CD. In Experiment 2, seven cores were randomly assigned to CD or FD. Liquid dairy manure was applied at 1.2 × 10 5 L ha −1 , followed by simulated rainfall 2 h later. Leachate was sampled on Day 7, 14, and 21. Deionized water was applied at 3.4 cm h −1 over 1 h to mimic a 10‐yr rainfall event. Total P (TP), soluble reactive P (SRP), dissolved oxygen, iron (Fe 2+ ), and pH were measured. Results showed that TP ( P = 0.03) and SRP ( P = 0.35) were lower for CD prior to manure application. Manure application caused 36‐ and 42‐fold increases in TP and SRP; however, TP was lower for CD at 7 ( P = 0.06), 14 ( P = 0.003), and 21 d ( P = 0.002) of water retention. Mean SRP for CD was nearly 40‐fold lower than FD by Day 7 ( P = 0.02) and remained low, suggesting CD in the field may reduce P export risk to tile drain flow after manure applications. Core Ideas Phosphorus can leach to tile drains in fields with macropore flow. Simulating controlled subsurface tile drainage reduced P leaching losses. Controlled drainage may help mitigate P transport to tile drains.