Spatiotemporal land use and cover changes across agroecologies and slope gradients using geospatial technologies in Zoa watershed, Southwest Ethiopia.

Environmental phenomena are always changing elsewhere in various scales depending on both natural phenomenon and human interference. Land use/over change (LULC) is related to site specific factors such as inappropriate land use planning and the expansion of traditional agricultural practices in steep gradients have led to soil erosion and consequent ecological changes. Thus, it is crucial to determine the trend, pattern, and drivers of land use/land cover dynamics for sustainable natural resource management in Ethiopia. Therefore, we evaluated the spatio-temporal LULC dynamics in different agroeclogies and slope gradients, and their drivers between 1985 and 2021 in the Zoa watershed of Omo-Gibe basin, Southwest Ethiopia. Landsat imageries, focus group discussants, key informants, and field observations were used as source of data to analyze the spatio-temporal LULC trajectories and their drivers. With total accuracies ranging from 87.55% to 91.14%, supervised image classification using the Maximum Likelihood classifier technique was used to categorize five key LULC classes: bareland, farmland, forestland, grassland, and shrubland. The results revealed that shrubland (41.87%) had the largest share in 1985, but later declined to 23.98% in 2000, and 12.6% in 2021. Grassland has declined as well, from 17.15% in 1985 to 2.09% in 2021. In contrast, farmland increased at the fastest rate, from 29.09% in 1985 to 71.12% in 2021. The proportion of farmland exhibited an increasing trend in all agro-ecologies, while forestland has increased only in highland agro-ecologies. Between 1985 and 2021, an extensive area of shrubland and grassland were converted into farmland with a conversation rate of 1.05% and 0.58% per annum, respectively. The expansion of farmland was observed towards moderately and steep rolling slopes which might exacerbate soil degradation. This is due to rapid population increase and ongoing demand for agricultural land. The result of key informant interviews and focus group discussions also revealed that expansion of farmland and settlement are the major drivers of LULC dynamics due to rapid human population growth. Therefore, the regional government and various stakeholders should work on redesigning effective management strategies through appropriate land use planning to address the adverse effects of LULC dynamics.

Quantitative Changes in Various Nutrient Ratios in Fodder Plants as an Effect of Compost and Fly Ash Application.

Despite the popularity of concentrated feed, fodder crops are still important, especially in organic livestock farming. However, this type of feed must meet certain criteria, which are often described using correct nutrient ratios. The research investigates the influence of compost and fly ash on quantitative changes in nutrient ratios determined for lupine and oat cultivated on soil slightly contaminated with Cu. A pot experiment was conducted on medium soil. Immobilizing agents (compost and fly ash) were applied at the dose of 40 t per ha. Plant materials were subjected to chemical analyses to assess their macronutrient content and, based on these data, mutual proportions of individual nutrients were calculated as mass ratios of K:Mg, K:Na, Ca:P, Ca:Mg, K:(Ca+Mg) and (K+Na):(Ca+Mg). Changes in ratio values were visualized using statistical tools, i.e., Anova, correlation coefficients and dendrograms. It was found that immobilizing agents constituted a source of the chosen nutrients because their amounts in plants grown on the soil fertilized with either compost or fly ash compost were significantly higher than in the control plants. This phenomenon was especially visible with regard to Ca and Mg for both lupine and oat. It should be emphasized here that the effect of compost or fly ash on the content of Ca and K in plants was comparable. In general, the application of compost contributed to higher values of the analyzed nutrients in both plants. The control and fertilized fly ash plants were characterized by lower values of nutrient ratios. The expected optimal value range of 2-3:1 was determined only for Ca:Mg, which was found in both lupine and oats. The proper values of K:Mg (2-6:1) were found only in the case of fodder plants cultivated on soil amended with compost.

Health Risk of Heavy Metals Related to Consumption of Vegetables in Areas of Industrial Impact in the Republic of Kazakhstan-Case Study for Oskemen.

Among various heavy metal sources the metallurgic industry is the most threatening because emitted metals presented are the chemical forms in which metals are found in soil are more bioavailable and thus very easily are introduced into the environment and spread in both soils and plants. In this study such a situation is presented and the potential negative effect of emitted metals on soil and vegetables is estimated. Therefore, the following indicators were used: bioconcentration factors calculated for the total amount of metals (BCF) as well as daily intake of metal (DIM) and health risk index (HRI). Analyzed soils and vegetables originated from allotment gardens located at different distances from local industrial plants. The greatest amounts of metals in investigated materials (soils and plants) were found for the industrial zone and the lowest for samples representing the suburban zone. Among the analyzed metals Zn showed the highest (223.94−2645.13 mg·kg−1 for soils and 9.14−49.28 mg·kg−1 for plants), and Cd the lowest levels (1.77−15.2 mg·kg−1 for soils and 0.05−0.46 mg·kg−1 for plants). Regardless of the metal, the lowest BCF values were calculated for plants from the industrial zone and the highest from the urban site. Generally, BCF values calculated for vegetables were low and comparable for carrots, tomatoes, and cabbage. BCF values obtained for beetroots were higher in comparison to other vegetables. Regardless of plants, DIM values for Cd and Pb were low and comparable. DIM values for Cu and Zn were higher, but simultaneously strongly differentiated depending on the analyzed vegetables. A similar tendency was found in the case of HRI. The highest values were recorded for Cu and Zn in tomatoes. Regardless of the individual metals, the calculated values for DIM and HRI indices increased in the following sequence: beetroot < cabbage < carrot < tomato. The Zn and Cu contents in the studied types of vegetables do not exceed the maximum permissible levels recommended by WHO/FAO. In contrast, Pb concentrations were higher than the imposed standards in all the analyzed vegetable samples. On the basis of obtained DIM and HRI indices, consumption of vegetables cultivated in industrial areas should be restricted due to health risks related to heavy metals contained in plants.