Premium
Aerating Grassland before Manure Application Reduces Runoff Nutrient Loads in a High Rainfall Environment
Author(s) -
Vliet L. J. P.,
Bittman S.,
Derksen G.,
Kowalenko C. G.
Publication year - 2006
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/jeq2005.0266
Subject(s) - environmental science , grassland , aeration , surface runoff , manure , nutrient , agronomy , hydrology (agriculture) , agroforestry , environmental engineering , waste management , ecology , engineering , biology , geotechnical engineering
The effect of mechanically aerating grassland before liquid manure application in the fall on surface runoff and transport of nutrients and solids was studied in a high rainfall area. The two treatments were control and aeration, the latter receiving one pass with an aerator perpendicular to the slope before fall application of liquid manure (dairy in Years 1–3 and swine in Year 4). Treatments were randomly assigned on 3 to 5% sloping land with a silt loam surface soil (Aquic Dystroxerept) planted in orchardgrass ( Dactylis glomerata L.). Runoff from natural rainfall events was sampled for nutrient and solids analysis. Aeration significantly reduced runoff and loads of suspended solids, total Kjeldahl N (TKN), and dissolved reactive P in all years. Annual runoff amounts were reduced by 47 to 81%, suspended and volatile solid loads by 48 to 69% and 42 to 83%, respectively, TKN loads by 56 to 81%, and total P (TP) loads by 25 to 75%. Loads of the soluble nutrient NH 4 –N, dissolved reactive P, and K were reduced by 41 to 83%. The first three runoff events after manure application accounted for approximately one‐third of the annual total runoff and solid and nutrient loads when averaged across treatments, with loads of TKN, K, and NH 4 –N totaling 4.4, 3.3, and 1.9 kg ha −1 , respectively. Aeration slightly increased downward movement of NO 3 –N, but not other nutrients in the soil. Thus mechanical aeration can be an effective tool for reducing runoff and loads of solids and nutrients after surface application of liquid manure on sloping grassland.