J.H. Von Thunen's "model" remains relevant today primarily for the theoretical aspects that draw a direct connection between distance from market and profitability of product. Von Thunen noted the increasing costs of land the closer one got to a city, and postulated that the transportation costs associated with different agricultural products -- taking into account the model's development prior to the full onset of the Industrial Revolution -- would be determinative of the structure that would naturally emerge around the city. Assuming, as was one once reasonably could, that the city in question would lie in a largely empty space surrounded by great expanses of flat terrain, and that agricultural products, both animal and vegetable, would involve different costs to bring to market, with animal being the easiest, as they were self-mobile, then there was a certain academic logic to Von Thunen's model. The relevance of the Von Thunen model to contemporary society remains broadly valid insofar as transportation costs continue to be determinative of some agricultural practices (see, for instance, the current "Buy Local" trend that emphasizes consumer purchases of locally-grown produce that didn't require fossil-fuel-burning means of transportation to arrive at market). The notion of concentric rings, however, was too convenient in the real-world of soil and climate considerations, and the fact of the majority of the world's population having settled within a couple of hundred miles of coastlines. The basic principles involved in the model, though, remain valid. Transportation costs associated with agricultural products remain an important consideration, and land costs remain very much relevant to decision-making regarding myriad industries, the latter being directly responsible for the elimination of thousands of farms around the country that became increasingly encroached upon by ever-expanding metropolises. As land values increased in traditionally suburban areas due to demand for quality housing in such areas, the costs associated with agricultural activities became prohibitively high. Farmers couldn't afford the property taxes associated with quality land close to cities due to the latter's horizontal expansion.
In short, the Von Thusen model remains relevant today, but given the historical context in which it was formulated, its practical application is very limited.
The von Thunen model of agricultural land use was developed in the pre-Industrialization era, and was a representation of the most efficient and economical use of land surrounding a metropolitan center, designed to maximize industry profit. The model consisted of four rings surrounding a central city – in the first ring were dairy farms and produce, things that could be quickly transported to market, where they could be sold fresh. The second ring consisted of timber – an important commodity which was difficult and costly to transport, thus earning it a position closer to the city. In the third ring was grown grains and other sweeping crops, placed further from the city because they had a longer lifespan than fresh produce and were lighter and easier to transport than lumber. Furthest from the city were ranches, placed so because animals may transport themselves into the city.
The model is based on many limiting assumptions – that the soil composition surrounding a city 360-degrees is uniform, that there are no geological anomalies such as mountains or rivers to disrupt the structure, that the city is indeed centrally, compactly located…there are many obvious shortcomings. And in our post-industrial society the shortcoming are even more manifold, due to the redistribution of jobs away from the agricultural sector and the emergence of the “suburb,” among other obvious differences. It is easy to imagine that von Thunen’s model would be obsolete in this day and age.
However, it still serves a prime example of the ideal distribution of land based on property cost and production. Alonso’s bid-rent theory is based heavily on von Thunen’s postulations on land rent costs for agricultural functions, work reflected in his model. The model lends itself well to modification, thus establishing itself as a jumping-off point for future models and arrangements.
The von Thunen model has weaknesses because it does not allow for things like roads or railroads that make it easier to transport goods over long distances. He also does not anticipate things like refrigerated transport that would allow even perishable things to be transported over long distances.
The von Thunen model is most relevant today in less developed countries. There, the development of transportation and food preservation is much less than in rich countries and von Thunen's model still applies to a greater degree. In the rich world, the model is also applicable in that it emphasizes that land near to cities is more expensive and therefore cannot really be used for uses that do not bring in a great deal of money per unit of land area.