Comparing Physical Quality of Forest and Pasture Soils in a Sicilian Watershed

Abstract

Forest and pasture soils should have differing properties due, for example, to differing root characteristics or livestock trampling rates, but contradictory results have been reported in the literature. The surface soil physical and hydraulic properties of five forest and pasture sites were determined in a Sicilian watershed. In general, forest soils had a significantly lower bulk density, p^ (by 17-35%), and a higher field saturated hydraulic conductivity, Kf( by a factor of 3.4-11.5), than pasture soils. Differences between the water retention characteristics of Forest and pasture soils were low when high levels of organic matter, OM (>7.1%), were detected for both land uses. The mean Kf^ varied with the amount of large pores (i.e., larger than 596 or 298 \im) in the soil. The mean of A";^ also increased with increasing OM content and decreased with an increase in p^ (coefficient of determination 0.69-0.74). According to existing guidelines for evaluating soil physical quality, a good or relatively good quality forest soil was a common result. At three sites, a worse pasture soil physical quality was detected than that of the forest.In conclusion, changing land use from pasture to forest should have a favorable impact on hydrologie processes in the sampled watershed due to the better physical quality of forest soils. The order of magnitude of the mean Kf^ was predictable using laboratory data. The applicability of the existing guidelines to assess soil physical quality was indirectly supported in this investigation because a better quality was expected for the forest soils than the pasture soils.

Field-saturated hydraulic conductivity measured by two techniques and at different sampling positions relative to maize-crop rows and interrows

“…Agnese et al (2011) obtained a good correlation of saturated hydraulic conductivity with soil structure and organic matter content.…”

“…According to Horn and Kutilek (2009), Ks is a strength parameter comprising the dynamic aspects of a porous system over time and space, also encompassing the functionality of processes of agricultural and environmental interest (HORN; KUTILEK, 2009;REICHERT et al, 2016). This measure is dependent on properties related to soil porosity, such as bulk, size, morphology, continuity, and pores orientation, being more dependent on structure compared to soil texture (GONÇALVES;LIBARDI, 2013), and considered an indicator of soil physical quality (REICHERT et al, 2009;AGNESE et al, 2011).…”

Structure alteration of a sandy-clay soil by biochar amendments

“…In particular, water dynamics is mainly affected by inter-aggregate porosity in non-structured soils, whereas intra-aggregate porosity influences water movements in more structured soils (Li and Zhang 2009;Ouyang et al 2013). The dual pore distribution depends upon the amount of organic material cementing the clay particles (Agnese et al 2011), according to the mechanism proposed by Lehmann et al (2007) already outlined above. According to the aforementioned behaviour, it is expected that the HEMC technique is suitable for the detection of improvement in soil aggregate stability as a consequence of biochar amendment through the measurement of water retention at high matric potential.…”

“…In fact, use of organic matter appears to favour soil water retention through increase in soil porosity and in the mean pore size diameter (Rawls et al 2003;Wagner et al 2007; Lehmann et al 2007;Agnese et al 2011).…”

Changes in Hydrological Response of Forest Conversion to Agroforestry and Rainfed Agriculture in Renggung Watershed, Lombok, Eastern Indonesia

“…The soil characteristics that may change includes soil structure, bulk density, soil organic matter (Hajabbasi et al 1997;Price et al 2010;Agnese et al 2011;Pirastru et al 2013). Land cover change from lowland tropical forests to tree cash crop plantation such as palm oil, rubber, and cacao practising agroforestry also could also decrease soil organic carbon up to 50%, particularly in the top soil (Straaten et al 2015).…”