Hinduism(Sanathana Dharma) is mainly a culture than a religion which is followed in India. The culture of one region is based on that region's weather conditions and nature. . Cremation of bodies is a real example of this fact. Soil in India is wet type and have more water in it. If dead bodies are buried under soil, the bio degradation take place and body fluids come out. Since the soil is wet enough, it is very much sure that those fluids will mix up with the water in soil and hence the drinking sources like wells and rivers will get polluted. This will lead to diseases.
Also cremation helps in not wasting the land. After cremating the bodies, there is practice in which some grains or rice seeds are put in the place of cremation(It is still followed in Southern part of India, not sure about other parts). This practice is a straightforward way in pointing out the importance of agriculture in Hinduism. This is practiced to make sure that the agricultural land is not wasted. The same land is again used for agricultural purposes. So in this culture there are no cemeteries, the same land again used for the farming.
All these are written in the Smrithies(example for Smriti is Manusmrithi and I don't know in which specific smrithi this practice is mentioned.), which contains the code of conducts to be followed by people following a culture. Each Smrithi is followed in a region for a particular period according to it's nature and weather conditions.. Smrithies are allowed to edit accordingly whenever needed.(This is a vast subject to discuss and out of scope of this question) If some 1000 years old books are saying that, you should follow some rule which were followed 1000 years ago, nobody is going to obey that rule. So the rituals and habits to be followed can be changed according to Hindu culture.
Also it will be helpful for you to refer to 16 samskaras to be followed in one person's life. From wikipedia: The samskāra (sanskaar) are a series of sacraments, sacrifices and rituals that serve as rites of passage and mark the various stages of the human life and to signify entry to a particular Ashrama (i.e. stage of life). The answer of the question is the 16th one, Antyeshti. see the link.
So according to Hindu culture, particular region or country can adopt their way of burying according to the nature and weather conditions. This is making a good sense. Suppose if in European countries, dead bodies are about to burn, people will have difficulty in following that, so they choose burying body in soil which is easy to follow. Also in Middle East countries most of the parts are deserts. So burning of body is not necessary in these areas according to the soil type and nature conditions. This is just an introduction, the real answer needs a good research on Smrities mentioned earlier.
(And as I am from south India, Kerala, here most of the Hindus prefer to cremate the body than bury in the soil.)