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A: BI, binarized image; OI, original image; SEM, scanning electron microscope.S S : M M Soil structure depends on its genesis and consists of highly variable pore and solid networks. Several internal and external factors aff ect the a ributes of these networks, with water being the most aggressive agent. In this study, we used selected fractal parameters (called descriptors) to quan fy the basic topological a ributes-compactness and connectedness-as well as lacunarity and roughness of porous materials, with special a en on to sampling error and popula on variance dynamics. Four microhorizons were sampled from a 1.0-by 1.0-by 1.6-m monolith during a long-term drying period under controlled condi ons. A compara ve fractal analysis of selected mul temporal (11 mo) and mul scale (50×, 500×, 1000×, and 5000×) scanning electron microscopy (SEM) images was accomplished for the following layers with contras ng texture or structure: loam topsoil, pure basal c compacted sand, and two amorphous lacustrine clays. The scale invariance (self-similarity) of pore and solid networks was documented. A complex rela onship was found between the descriptor mean values and corresponding variances. Simple power-law rela ons were established between the standard devia on (and variance) and layer depth, as well as scale and sampling me. Pearson's r correlaon criterion was applied to measure the degree of associa on between mul objec ve fractal descriptors. Systema c and standardized fractal analysis of mul scale images is recommended for the sta s cal quan ta ve descrip on of complex and dynamic pore and solid networks.

There is a lack of information concerning the history of soil science in developing countries such as Mexico. This article examines the history, development, and challenges of soil science in Mexico. Soil knowledge in the pre‐Colombian era was a notable attribute of indigenous people in Mexico. Mayas and Aztecs classified soils based on properties and land use and developed a terminology still used by locals. In addition, international organizations and institutions advocating modern agricultural practices have played an important role in the development of soil science in Mexico, in conjunction with the Green Revolution in which the use of fertilizers for crop production was implemented. Soil fertility, as an area of study, has developed significantly in the country. One of the most significant impacts of the Green Revolution on the development of soil science in Mexico was through academic exchange, in which Mexican soil scientists obtained graduate‐level degrees in the United States and later returned to Mexico to conduct research programs. Although Mexico has a long history of soil knowledge, soil scientists are facing several challenges today, including the lack of communication between farmers and scientists, soil erosion, soil contamination, and water usage. Some researchers have suggested that ethnopedological knowledge should be incorporated into modern soil science.

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