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Use of Warm‐Season Grasses Managed as Bioenergy Crops for Phytoremediation of Excess Soil Phosphorus
Author(s) -
Silveira Maria L.,
Vendramini Joao M. B.,
Sui Xiaolin,
Sollenberger Lynn E.,
O’Connor George A.
Publication year - 2013
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj2012.0307
Subject(s) - panicum virgatum , pennisetum purpureum , agronomy , panicum , tifton , bioenergy , saccharum officinarum , environmental science , crop , dry matter , zoology , biology , biofuel , ecology
Effective options for reducing P losses from P‐enriched soils remain a major challenge, particularly in intensive agricultural areas. While different strategies have been shown to control P mobility (e.g., Ca‐ and Al‐based soil amendments and riparian buffers), they provide no means to reduce in situ soil P concentrations. The objectives of this study were to: (i) investigate the potential P‐removal capacity of four bioenergy crops (elephantgrass [ Pennisetum purpureum Schumach.], sugarcane [ Saccharum spp.], switchgrass [ Panicum virgatum L.], and stargrass [ Cynodon nlemfuensis Vanderyst]) grown on a manure‐enriched soil, and (ii) examine the impacts of crop P uptake on soil P concentrations and surface groundwater quality. Treatments were distributed in a completely randomized design with four replicates. The greatest dry matter yields were observed for elephantgrass (average of 46 Mg ha −1 yr −1 ) followed by sugarcane (average of 40 Mg ha −1 yr −1 ). Tissue P concentrations were greater for stargrass (∼4 g kg −1 ) than elephantgrass (3.2 g kg −1 ) or sugarcane (1.9 g kg −1 ). Elephantgrass showed the greatest cumulative P removal (420 kg P ha −1 during the 3‐yr period). Soil P concentrations in the Ap horizon decreased with time, while an increase in soil P concentration was observed in the Bh horizon. Elephantgrass resulted in the lowest leachate P concentrations (∼0.5 mg P L −1 ) at the 60‐cm depth. Crop species had no effect on leachate P at the 90‐cm depth. Growth of elephantgrass as a biofuel feedstock appears to be an effective approach for remediation of excess soil P.