Spent coffee grounds as organic amendment modify hydraulic properties in a sandy loam Brazilian soil

Sequential effects of spent coffee grounds on soil physical properties

“…The increase in W 33 agrees with that established by Turek et al (2019) for the addition of SCG in doses of 5%, 10%, 15% and 20%, attributing it to the changes in the OC contents in the soil. They also coincide with the results of Badaou and Sahin (2021) for the addition of sewage sludge (150 Mg ha −1 , corresponding to the addition of 2.5%).…”

“…The tendency to increase the micro and mesoaggregates with the addition of SCG (Figure 3) could also be related to the increase in W 33 , since this water is more related to the structure than to granulometry (Rajkai et al, 2015). However, Turek et al (2019) observe a decrease between 15% and 20% SCG attributing it to the modification of the microporous structure when adding SCG to the soil. In our case, we have not reached these SCG contents, but the trends in aggregate sizes (Figure 3) indicate that from 10% the micro and mesoaggregate contents decrease and those of macroaggregates increase, which would coincide with what is indicated by these authors.…”

“…The increase in W 1500 has also been observed for other types of waste such as composted olive peel and compost and poultry manure (Forge et al, 2016; Moreno et al, 2016). However, with respect to plant available water content, Turek et al (2019) observed an increase in it after the addition of SCG. Our results contradict those of these authors, which may be due to the different type of soil used, mainly in terms of clay content: clayey in our case and sandy and silty in the case of Turek et al (2019).…”

“…However, with respect to plant available water content, Turek et al (2019) observed an increase in it after the addition of SCG. Our results contradict those of these authors, which may be due to the different type of soil used, mainly in terms of clay content: clayey in our case and sandy and silty in the case of Turek et al (2019). On the contrary, our results coincide with those of Forge et al (2016) and Zhang, Wang, et al (2022) by adding compost of bird manure for 1 year in a Podzol type soil, that is, sandy and peat grass in a loamy soil respectively.…”

“…There is little research on the effects of SCG dosage on soil properties. Turek et al (2019) studied the sequential effect of increasing doses of SCG (5%, 10%, 15% and 20%), but did so on a sandy loam soil from Brazil. These authors found a 31% increase in water retention capacity with the addition of SCG, although it decreases 15 and 20% between the doses which they associate with pore geometry, which has been moulded by the SCG, modifying its shape, tortuosity, continuity and conductivity.…”