Moisture, Water Holding, Drying and Wetting in Forest Soils

Abstract

Relationship of soil and water is generally considered as important in soil science. To specify it further we studied two different soils in 2012-2013, three additional soils once and made several series of experiments with drying and wetting of the soils. Principal parameters studied were the gravimetric water content (GWC), water holding capacity (WHC), soil organic matter (SOM), their correlations and rates of change in drying or wetting. The three parameters are significantly intercorrelated. Distribution of GWC in the replicates of soils dried both in nature and in experiments was narrower than that in wet soils, while WHC changed less in drying. The correlations (GWC-WHC) became steeper (the slope coefficient higher) and the coefficient of determination (R 2) lower. Attempts to increase WHC in wet soils with a high WHC even further were not successful. Drying may be fast or slow; rates of increase of WHC in wetting were all low, both in field and in the experiments, less than 0.1 g (H2O) g −1 (soil)•day −1. None of the three parameters can be considered as fixed characteristics of forest soils.

Nodule-forming Sinorhizobium and arbuscular mycorrhizal fungi (AMF) improve the growth of Acacia farnesiana (Fabaceae): an alternative for the reforestation of the Cerro de la Estrella, Mexico

“…Physicochemical analysis of the soil. Three soil samples were collected randomly around 1 m 2 at Cerro de la Estrella, Mexico City (19° 20' 31" N,99° 05' 22" W,altitude 2,460 m), air dried and sieved for physicochemical characterization, including soil texture (Bouyoucos hydrometer method), water holding capacity (gravimetric method) (Blažka & Fischer 2014), pH (using a glass electrode, 1:2 soil: distilled water suspension) and electrical conductivity (1:2 soil: distilled water suspension) (Rhoades et al 1989). Organic carbon content (C) was determined by oxidation with K 2 Cr 2 O 7 and titration of excessive dichromate with (NH 4 ) 2 FeSO 4 .…”

Soil Respiration in the Profiles of Forest Soils in Inland Dunes

“…Hudson suggested that Z. Fischer, L. Dubis the amount of organic matter plays a significant role in this difference. Blažka drew attention to the fact that the higher water holding capacity of soils with high organic matter content may be due to the hydration of the organic substance by the creation of so-called "water bridges" [25]. In this way, soil organic matter has to be considered not only a nutrient but also an element that widely regulates humidity.…”

“…WHC relates to organic matter according to the linear regression WHC = 3.153 × SOM + 0.2121, R 2 = 0.92. In the years 2012-2013, in the same areas and in various seasons, an investigation of the relation between SOM and WHC was carried out on 240 soil samples; this relation was also found to be quite significant R 2 = 0.88, with the equation WHC = 5.58 × SOM + 0.50[25].…”

Soil Respiration in Drying of an Organic Soil

“…The location is on the northern outskirts of the city of Warsaw (Poland). Geographic coordinates are: 52˚20'212 N, 020˚51'260 E, elevation 81 m. Refer to Blazka and Fischer [18]. The aim of the study is understands of mechanisms of drying through laboratory experimentation and not description of a particular locality.…”

“…Our procedure was based essentially on Grace et al, Priha and Smolander [20] [21] with minor modifications [18]. GWC and other contents are given as ratios, but not %.…”