The protected areas of Rwanda are facing various challenges resulting from the anthropogenic activities of the surrounding communities, especially in the adjacent area to Cyamudongo isolated rain forest, which results in soil degradation. Therefore, this study aims to broaden current knowledge on the impact of sustainable Agroforestry (AF) on soil-selected chemical and physical properties. To understand this, the permanent sample plots (PSPs) were established mainly in the designed four transects of four km long originating on the boundary of the Cyamudongo isolated rain forest following the slope gradient ranging from 1286 to 2015 m asl. A total number of 73 PSPs were established in the Cyamudongo study area. The Arc Map GIS 10.4 was used to design and map the sampling areas while GPS was used for localization of plots centers. Statistical significance was analyzed through R-software. The recorded soil pH means value across in Cyamudongo study area is 4.2, which is strongly acidic. The tests revealed that the soil pH, C, N, C: N ratio, OM, NH4+, NO3-+NO2-, PO43-, and CEC were significantly different in various soil depths. The pH, N, C: N ratio, CEC, NH4+, PO43-, and Al3+ showed a significant difference across land uses whereas the C and NO3-+NO2- did not show any statistical difference. All tested chemical elements showed a statistical difference as far as altitude ranges are concerned. The only NH4+, PO43-, and CEC showed significant differences with time whereas all other remaining chemical elements did not show any statistical significance. The soil pH was very strongly correlated with CEC, Mg, and Ca in cropland (CL) whereas it was strongly correlated in both AF and natural forest (NF) except for Mg, which was moderately correlated in AF. Furthermore, its correlation with K was strong in CL, and moderate in AF while it was weak in NF. Finally, the pH correlation with Na was weak in both AF and CL whereas it was negligible in NF.

Tokat is one of the developing provinces in terms of urbanism. Therefore, the land use changes city-wide which closely affects soil erosion. Numerical estimation of soil erosion is very important to prevent soil losses. In this study, USLE and WEPP Hillslope model were used to estimate the long-term soil losses in a slope area which used to be a pasture land and then turned into a fruit orchard in Büyükbeybağı area of Tokat province. Erosion sensitivity of the soil in the slope area was detected to be very low. Erosivity value of the area is low, soil is resistant to erosion due to pasture land use type and fruit orchard use type does not require intense soil cultivation practices. For all these reasons, both estimation technologies estimated soil losses of the land to be low.

In ecological studies, soil-plant interaction is an important environmental factor. Soil chemical and physical properties affect plant richness and diversity. This study was carried out to investigate the relationship between soil physical and chemical properties, and plant diversity indexes (Shannon-Weiner and Simpson) in semiarid grassland. Plant diversity indexes and soil properties were determined using 34 quadrats (5x5m) on different parent materials (chrome, marble, serpentine, red chalk and red chalk mostra) in semiarid grasslands in the Central Anatolia Region in Turkey. Plant samples were collected and recorded periodically from April to September (the vegetation period) in 2014 for each quadrat. In order to determine the plant richness and diversity indexes, 3 sub-quadrats (1x1m) were randomly added into each of 34 (5x5 m) quadrats. To evaluate the relationship between plant diversity indexes and soil properties, composite soil samples were collected from the four corners, and the center of each quadrat 0-30 cm in depth, and which was mixing of those subsamples. Soil sand-silt-clay contents, soil reaction (pH), bulk density (BD), electrical conductivity (EC), CaCO3 and soil organic matter (SOM) contents were measured. Relationship between plant diversity indexes measured in different months during vegetation period and soil properties of different parent material was statistically analysed using correlation analysis in SPSS 20.0. Modest correlation coefficient was found between the Simpson diversity index and SOM content, sand-silt-clay content, pH and EC for different months in vegetation period.