The Assessment of Water Retention Efficiency of Different Soil Amendments in Comparison to Water Absorbing Geocomposite

Abstract

Soil amendments are substances added to the soil for moisture increment or physicochemical soil process enhancement. This study aimed to assess the water conservation efficiency of available organic soil amendments like bentonite, attapulgite, biochar and inorganics like superabsorbent polymer, and nonwoven geotextile in relation to the newly developed water absorbing geocomposite (WAG) and its biodegradable version (bioWAG). Soil amendments were mixed with loamy sand soil, placed in 7.5 dm3 pots, then watered and dried in controlled laboratory conditions during 22-day long drying cycles (pot experiment). Soil moisture was recorded in three locations, and matric potential was recorded in one location during the drying process. The conducted research has confirmed that the addition of any examined soil amendment in the amount of 0.7% increased soil moisture, compared to control, depending on measurement depth in the soil profile and evaporation stage. The application of WAG as a soil amendment resulted in higher soil moisture in the centre and bottom layers, by 5.4 percent point (p.p.) and 6.4 p.p. on day 4 and by 4.5 p.p. and 8.8 p.p. on day 7, respectively, relative to the control samples. Additionally, an experiment in a pressure plate extractor was conducted to ensure the reliability of the obtained results. Soil density and porosity were also recorded. Samples containing WAG had water holding capacity at a value of −10 kPa higher than samples with biochar, attapulgite, bentonite, bioWAG and control by 3.6, 2.1, 5.7, 1 and 4.5 percentage points, respectively. Only samples containing superabsorbent polymers and samples with nonwoven geotextiles had water holding capacity at a value of −10 kPa higher than WAG, by 14.3 and 0.1 percentage points, respectively. Significant changes were noted in samples amended with superabsorbent polymers resulting in a 90% soil sample porosity and bulk density decrease from 1.70 g∙cm−3 to 1.14 g∙cm−3. It was thus concluded that the water absorbing geocomposite is an advanced and most efficient solution for water retention in soil.

Release efficiencies of potassium permanganate controlled-release biodegradable polymer (CRBP) pellets embedded in polyvinyl acetate (CRBP-PVAc) and polyethylene oxide (CRBP- PEO) for groundwater treatment

“…In sand, where the porosity is 0.5, about 72–73 % of the KMnO 4 is released over 65.79 pore volumes of water at both pH 6.0 and 8.0 ( Table S11 ). This indicates a relatively high longevity of the release material in sandy soils which can be attributed to the larger pore volume facilitating the movement of water and hence the release of KMnO 4 from the pellets [ [92] , [93] , [94] , [95] ].…”

Composting of recovered rock wool from hydroponics for the production of soil amendment

“…Earthworms are considered suitable bioindicators of soil pollution because they are in constant contact with the soil and feed on soil particles due to their thin cuticle and chemoreceptors with which they receive stimuli and pollutants all over their body (Paoletti 1999 ; Ebagnerin Tondoh et al 2006 ; Piron et al 2012 ). They have been used as indicators of soil contamination with heavy metals (Suthar et al 2008 ), pesticides (Yao et al 2020 ), and persistent organic pollutants (Shi et al 2019 ). Interestingly, gRMW mixtures with compost were unfavourable to earthworms and most of them were found in the control substrate.…”

Assessment of the Effect of Soil Amendments and A Three Phase Soil Water Retention Model

“…The other one is synthetics, such as biochar, superabsorbent polymer (SAP) (Huang et al, 2022), non-woven geotextiles and water absorbing geo-composites (Orzeszyna et al, 2006;Mohawesh and Durner, 2019). Both types can effectively improve soil water retention to reduce both water infiltration below the surface and evaporation at the surface (Keiblinger and Kral, 2018;Spitalniak et al, 2021).…”