Controlled Application Rate of Water Treatment Residual for Agronomic and Environmental Benefits

Abstract

Water treatment residuals (WTR) are useful soil amendments to control excessive soluble phosphorus (P) in soils, but indiscriminate additions can result in inadequate control or excessive immobilization of soluble P, leading to crop deficiencies. We evaluated the influence of application rates of an Al-WTR and various P-sources on plant yields, tissue P concentrations, and P uptake and attempted to identify a basis for determining WTR application rates. Bahiagrass (paspalum notatum Fluggae) was grown in a P-deficient soil amended with four P-sources at two application levels (N- and P-based rates) and three WTR rates (0, 10, and 25 g kg(-1) oven dry basis) in a glasshouse pot experiment. The glasshouse results were compared with data from a 2-yr field experiment with similar treatments that were surface applied to an established bahiagrass. Soil P storage capacity (SPSC) values increased with application rate of WTR, and the increase varied with sources of P applied. Soil soluble P concentrations increased as SPSC was reduced, and a change point was identified at 0 mg kg(-1) SPSC in the glasshouse and the field studies. A change point was identified in the bahiagrass yields at a tissue P concentration of 2.0 g kg(-1), corresponding to zero SPSC. Zero SPSC was shown to be an agronomic threshold above which yields and P concentrations of plants declined and below which there is little or no yield response to increased plant P concentrations. Applying P-sources at N-based rates, along with WTR sufficient to give SPSC value of 0 mg kg(-1) SPSC, enhanced the environmental benefits (reduced P loss potential) without negative agronomic impacts.

Assessing effects of aerobic and anaerobic conditions on phosphorus sorption and retention capacity of water treatment residuals

“…For example, Basta et al (1996) applied WTRs to soils treated with poultry manure and successfully reduced P in run-off by more than 50%. The same degree of P retention has been demonstrated in other, more recent studies (Agyin-Birikorang et al, 2007;Oladeji et al, 2007Oladeji et al, , 2008. In addition, Macks and co-workers (Macks, 1997;Macks et al, 1998) have shown that WTRs could be used to successfully remove P from agricultural waste waters.…”

Applicability of drinking water treatment residue for lake restoration in relation to metal/metalloid risk assessment

“…Meanwhile, Oladeji et al . observed no increase in Al content in Bahiagrass or ryegrass (Lolium perenne L.) from Immokalee fine sand (Alaquods) applied with DWTR43. These differences may be mainly related to the different soil properties and plants used in the tests4243.…”

Water Treatment Residuals and Biosolids Long‐Term Co‐Applications Effects to Semi‐Arid Grassland Soils and Vegetation

“…Th e decrease in plant P content was due to P adsorption on to WTR, and Bayley et al (2008a) showed that WTR acts as the major P sink in this system. Others (Oladeji et al, 2007;Lucas et al, 1994;Elliott and Singer, 1988;Bugbee and Frink, 1985) have found reduced P content of plants grown in WTR-amended soils. Mahdy et al (2007), however, found that WTR addition at rates up to 30 g kg -1 to calcareous soils signifi cantly increased corn P shoot and root concentrations.…”