Effects of water treatment residuals and coal combustion byproduct amendments on properties of a sandy soil and impact on crop production – A pot experiment

Authors: Alva, Ashok; SAJWAN, K - SAVANNAH ST. UNIV; PARAMASIVAM, S - SAVANNAH ST. UNIV

Submitted to: Archives of Agronomy and Soil Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/2011
Publication Date: 1/1/2011
Citation: Alva, A.K., Sajwan, K., Paramasivam, S. 2011. Effects of water treatment residuals and coal combustion byproduct amendments on properties of a sandy soil and impact on crop production – A pot experiment. Archives of Agronomy and Soil Science. 2011:1-10.

Interpretive Summary: Environmentally acceptable disposal of byproducts of coal fired electric power plants (i.e. fly ash), municipal water treatment plants (i.e. sewage sludge) and livestock industries (i.e. animal or chicken manure) is of major concern. The above byproducts contain one or more plant essential nutrients at rather low concentrations. Therefore, application of the above byproducts as agricultural soil amendments has been evaluated. This approach is appealing to the agricultural producers provided that no negative effects on the crop production/quality as well as on the soil and water quality are documented. In a pot experiment, the affects of application of varying rates of either chicken manure, sewage sludge, incinerated sewage sludge, or fly ash at various rates on two potato cultivars (‘Russet Burbank’ and ‘Umatilla Russet’) were evaluated using a sandy soil representative of major potato production region in the United States Pacific Northwest. In both cultivars, tuber yield was significantly reduced only at the high rate of sewage sludge amendment (89.6 metric tonnes/ha). This pot study demonstrated that application of high rates of these byproducts, except sewage sludge, had no negative effects on the tuber yields of both cultivars. The residual affects of these amendments on the subsequent crops (in a potato rotation) as well as repeated annual application of these byproducts at various rates have yet to be investigated.

Technical Abstract: Byproducts of coal combustion (such as fly ash: FA), livestock industry (such as chicken manure: CM, or animal manure, etc), or water treatment residuals (such as sewage sludge: SS, or incinerated sewage sludge: ISS) can be used as amendments to agricultural soils, provided that these byproducts (applied as single source or in combination) contribute to an improvement in the soil physical, chemical, or biological properties without causing any negative effects on the soil and/or water quality as well as crop growth or production. There is an increasing interest in land application of these byproducts at high rates to dispose these byproducts as an alternative to stockpiling in landfills. This approach requires demonstration of: (i) no negative effects of application of these materials on agricultural soils, crop production and/or environmental quality; and (ii) some beneficial effects on crop yield and/or quality associated to use of these by products as soil amendments. A pot experiment was conducted to investigate the effects of application of high rates of either CM (5.6, 11.2 or 22.4 Mg ha-1; i.e. metric tones per hectacre), SS, ISS, or FA (each at 22.4, 44.8, or 89.6 Mg/ha) on a Quincy fine sand (mixed, mesic, Xeric, Torripsamments) both in terms of soil properties as well as growth (130 days) and tuber yield of two potato cultivars (Russet Burbank: RB, and Umatilla Russet: UR). In the case of RB cultivar, no significant affect was evident with most of the amendment treatments as compared to the unamended treatment. A significant reduction in tuber yield was observed with 89.6 Mg/ha SS. In the case of UR cultivar, however, tuber yield increased with 11.2 Mg ha/ha CM or 89.6 Mg/ha ISS, and decreased with 89.6 Mg/ha SS compared to that in the unamended treatment. A significantly greater vegetative growth (leaves and stems) was evident in the UR cultivar with a high rate of SS, which may, in part, explain the significant reduction in the tuber yield. However, the above trend was not evident with the RB cultivar. Sequential fractionation of metals in the soils revealed significant treatment effects on the distribution of different forms (readily soluble, organically bound, precipitated, and residual forms) of Cu and Zn, particularly with respect to various rates of SS and ISS. The concentration of total Cu and that of Cu in the organically bound and precipitated forms increased with increasing rates of SS and ISS. The magnitude of the difference was greater with the latter as compared to that of the former. A similar trend was also evident with respect to Zn, except that the magnitude of difference between SS and ISS rates was less apparent than that for Cu.