Using Paper De‐inking Sludge to Maintain Soil Structural Form Field Measurements

Abstract

A high level of organic matter in soils is crucial to maintain structural stability but organic matter sources differ in their effectiveness in stabilizing structural units. Objectives of this study were, first, to determine the optimal rate of sludge and fertilizer application to improve soil physical properties, and second, to investigate a possible correlation between hydraulic conductivity and structural stability measurements. A 4‐yr field study (1994–1997) was conducted on three different soil types to evaluate the effect of different amounts of de‐inking secondary paper sludge on the soil physical properties. The soil physical properties we monitored were structural stability, water desorption characteristics, bulk density, and saturated hydraulic conductivity. Structural stability was increased by 17% in silty clay soil (SCS) and 15% in loamy soil (LS), but decreased by 35% in sandy loam soil (SLS). Results suggest that the effect of sludge application (SA) is short‐lived and that an annual application of sludge is necessary to obtain a year‐to‐year effect on structural stability. Measured bulk density dropped significantly in the SCS (4–10%) and in the LS (1–6%). A significant increase in air capacity and available water values revealed that SA increases both transmission and storage pores in the SCS. Field‐saturated hydraulic conductivity (Kfs) was increased in the SCS, but decreased in the SLS and the LS. A good correlation was observed between structural stability and hydraulic conductivity measurements in the SCS and the LS.

Effect of de-inking paper sludge compost application on soil chemical and biological properties

“…However, an increase in soil water content in DSPC-treated plots was not observed in 1997, suggesting that the presence of undecomposed material in the DSPC was responsible for this temporary increase. Similar shortterm effects were reported previously for raw de-inking paper sludges (Trépanier et al 1996;Aitken et al 1998;Simard et al 1998a), combined primary and secondary sludges (Cambouris et al 2000;Nemati et al 2000) and manure and commercial composts (Gagnon et al 1998). For personal use only.…”

Physical properties of some intensively cultivated soils of Ireland amended with spent mushroom compost

“…Similarly, Kaddous andMorgans (1986), andMurphy (2001) reported an increase ( p < 0Á05) in percent water-stable aggregates as a result of SMC application. Amendments of either type of SMC had the capacity to increase the aggregate stability of the soil it was applied to, however, and similar to the observations reported by Nemati et al (2000) and Gagnon et al (2001) for paper residue amendments, neither fresh nor composted SMC amendment universally enhanced soil structural stability. Despite this, it was observed that fresh SMC amendments on occasion yielded more resistance aggregates than did similar additions of composted SMC.…”

Pulp and paper mill by-products as soil amendments and plant nutrient sources

“…The abundance of aggregates >5 mm and the mean weight diameter of aggregates were reported to decrease when the fresh combined paper sludge was added to soil with mineral N fertilizer (Bipfubusa et al 2005), also implying that benefits to aggregation are dependent on relatively undecomposed sludge. Lower sludge rates resulting in lesser increases in soil organic matter in the studies of Trépanier et al (1996a) and Nemati et al (2000) may explain the less persistent effects on soil aggregation in comparison with the research of Chantigny et al (1999) and Gagnon et al (2001). Zibilske et al (2000) clearly showed that the onset and magnitude of decreased bulk density and increased aggregation of a fine sandy loam were dependent on the rate (45 to 235 Mg ha -1 ) and frequency (once, biennially, and annually) of combined sludge application.…”

“…Wet aggregate stability of a silty clay and a loamy soil was increased 15-17% by application of a combined sludge (C:N ratio of 160:1, 85% deinking sludge/15% secondary sludge) at 8 to 24 Mg ha -1 (Nemati et al 2000). Enhanced stability persisted for about 1 yr, indicating annual applications were necessary for continuous benefit.…”