%0 Journal Article
%T Fly Ash and Composted Biosolids as a Source of Fe for Hybrid Poplar: A Greenhouse Study
%A Kevin Lombard
%A Mick O'Neill
%A April Ulery
%A John Mexal
%A Blake Onken
%A Sue Forster-Cox
%A Ted Sammis
%J Applied and Environmental Soil Science
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/475185
%X Soils of northwest New Mexico have an elevated pH and CaCO3 content that reduces Fe solubility, causes chlorosis, and reduces crop yields. Could biosolids and fly ash, enriched with Fe, provide safe alternatives to expensive Fe EDDHA (sodium ferric ethylenediamine di-(o-hydroxyphenyl-acetate)) fertilizers applied to Populus hybrid plots? Hybrid OP-367 was cultivated on a Doak sandy loam soil amended with composted biosolids or fly ash at three agricultural rates. Fly ash and Fe EDDHA treatments received urea ammonium nitrate (UAN), biosolids, enriched with N, did not. Both amendments improved soil and plant Fe. Heavy metals were below EPA regulations, but high B levels were noted in leaves of trees treated at the highest fly ash rate. pH increased in fly ash soil while salinity increased in biosolids-treated soil. Chlorosis rankings improved in poplars amended with both byproducts, although composted biosolids offered the most potential at improving Fe/tree growth cheaply without the need for synthetic inputs. 1. Introduction The New Mexico State University Agricultural Science Center at Farmington, San Juan County, has been exploring short rotation hybrid poplar trees for fiber and timber production, biofuel, and phytoremediation purposes. Adaptability trials involving numerous Populus crosses have produced a range of responses. Of these, Fe deficiency chlorosis (interveinal yellowing of juvenile leaves) has been observed because soil pH can exceed 8 with moderate to high CaCO3 levels. Under these conditions, soil iron is mostly in the form of well-crystallized iron oxides (e.g., hematite and goethite) and almost insoluble and unavailable to plants [1]. On our research plots, chelated iron fertilizer in the form of Fe EDDHA is applied to alleviate chlorosis symptoms. Considering that 5£¿kg Fe EDDHA material¡ªenough to cover approximately 1£¿ha season£¿1¡ªcosts approximately $200, fertilizing large-scale plantations may be cost prohibitive. On the other hand, fly ash, a byproduct from coal combustion, can provide plant-available Fe and other micronutrients [2¨C7]. Fly ash exits the combustion chamber with the flue gas and is captured by electrostatic precipitators, wet scrubbers, or other mechanical/chemical trap [8]. Particle sizes range from 0.01 to 100£¿¦Ìm allowing a large amount of surface area to mass [9]. Nearly 3.9 million Mg of coal combustion products (ash + flue gas desulfurization products) are produced in San Juan County each year by two coal fired generating plants, and both power plants are actively seeking recycling options (Salisbury, 2003,
%U http://www.hindawi.com/journals/aess/2011/475185/