The effect of afforestation with Scots pine (Pinus silvestris L.) of sandy post-arable soils on their selected properties. II. Reaction, carbon, nitrogen and phosphorus

Abstract

Despite the extensive literature on the effect on soil properties of afforestation of former arable land, we still lack full understanding of whether the changes proceed in the same direction and at the same rate, and of how long is required to achieve a state of soil equilibrium typical of a natural forest ecosystem. Therefore, as part of a study comparing post-arable sandy soils (Dystric Arenosols) afforested with Scots pine (Pinus silvestris L.) with arable soils and soils of continuous coniferous forests, the range and direction of changes in pH, organic carbon (C org ), total nitrogen (N tot ), ammonium (N-NH 4 ) and nitrates (N-NO 3 ) in soil solution, total (P tot ) and available (P av ) phosphorus were determined. The studies were carried out in south-east Poland (51°30′-51°37′N, 22°20′-22°35′E). Ten paired sites of afforested soils (five with 14-to 17-year-old stands and five with 32-to 36-year-old stands) with adjacent cultivated fields, and five sites of continuous forest with present stands of ca. 130-150 years old were selected. Soil samples were taken from the whole thickness of master horizons and, in the case of the A horizon of the afforested soils, from three layers: 0-5 (A 0-5 ), 5-10 (A 5-10 ) and 10-20 cm (A 10-20 ). The cultivated soils in the Ap horizon showed higher pH (by ca. 1.0 unit), lower C org and C:N, similar N tot , lower N-NH 4 , higher N-NO 3 , higher P tot and P av contents compared with the Ah horizon of continuous forest soils. The results indicated decreased soil pH in the former plough layer of the afforested soils, with the greatest decrease observed in the 0-5 cm layer. In these soils, the C org content was considerably higher in the A 0-5 layer, but lower in the two deeper layers and in the whole A horizon (0-20 cm) compared with the Ap horizon of the arable soils. The results indicate that the C org content, after an initial phase of decline, again achieved a level characteristic of arable soils. The N tot content in all layers of the A horizon of the afforested soils was lower than in the Ap horizon of the arable soils, and showed a reduction with stand age, especially in deeper layers. The C:N ratios in the mineral topsoil increased with stand age. N-NH 4 content increased and N-NO 3 decreased after afforestation. The P tot and P av contents in all layers and in the whole A horizon of the afforested soils, on stands of both ages, was lower than in the Ap of the cultivated soils. From the results, it could be concluded that, after more than 30 years of tree growth, the soils of the A horizon were still more similar to arable than to continuous forest soils with respect to C org , P tot and P av . With respect to pH, N-NH 4 and N-NO 3 , especially in the 0-5 cm layer, they were more similar to continuous forest soils than to Plant Soil (2008) 305:171-187

Former agriculture impacts on properties of Norway spruce forest

“…Stand age may also be a factor here. Alriksson and Olsson (1995), Ritter et al (2003), Wall and Hytönen (2005), Cerli et al (2006), and Smal and Olszewska (2008) all had conf irmed an important role of age in relation to increasing acidification, as they had found lower pH in forest floor and soil of older stands origin compared with younger afforestation. Keersmaeker et al (2004) had found no correlation between age and pH, however, even though pH's variability was greater in soil of longterm forest origin.…”

“…Therefore, increased content of this nutrient in soil can be attributed to deliberate ameliorative efforts in the past (Bedrna, 2002). Formerly agricultural soils (Koerner et al, 1997;Falkengren-Grerup et al, 2006;Armolaitis et al, 2007;Oheimb et al, 2008;Valtinat et al, 2008) and contemporarily cultivated soils (Ellert and Gregorich, 1996;Smal andOlszewska, 2008, Podrázský et al, 2009) have been shown to be better supplied with phosphorus relative to uncultivated soils. In measuring phosphorus concentrations in forest floor at our study sites, we found increased values also for formerly cultivated sites.…”

“…We therefore can estimate the rate of forest floor humification using the C/N ratio. Comparing topsoil C/N ratios for continuous and afforested sites, many authors (Ellert and Gregorich, 1996;Koerner et al, 1997;Compton et al, 1998;Jussy et al, 2002;Ritter et al, 2003;Prévosto et al, 2004;Oheimb et al, 2008;Smal and Olszewska, 2008;Valtinat et al, 2008) have found significantly lower values in formerly agricultural soil in comparison with forest soil. In agreement with information from the literature, we found significantly lower C/N ratios in 0-10 cm of topsoil of formerly agricultural soil compared to adjacent long-term forest soil.…”

Soil carbon and nitrogen stocks in traditional agricultural and agroforestry systems in the semiarid region of Brazil

“…Some authors observed increases in TN stocks after the conversion of land into agroforestry systems (Sartori et al, 2007;Morris et al, 2007), while others reported decreases in TN stocks upon conversion (Smal & Olszewska, 2008). The low TN stocks could be related to low plant residue input, the accumulation of the aerial parts of plants and the lack of N fertilization, while the high stocks could be related to plant residue sedimentation and atmospheric N (Mao et al, 2010).…”

Diagnosis of medieval-era ploughing using phytolith analysis by the example of archaeological sites Kuckarki and Knyazhich of Moscow region

“…В экспонированных почвах эти признаки исчезают в течение первых сотен лет [Макаров, 1984;Sergerström, 1991;Cartet, Davidson, 1998;Usai, 2001;Караваева, 2005;Fagan et al, 2008;Гольева, Зазовская, 2008;Smal, Olszewska, 2008;Spohn et al, 2015]. Визуально диагностировать более раннюю распашку становится невозможно.…”