Final answer:
Intensive subsistence agriculture includes labor-intensive techniques such as (1) terracing and (3) crop rotation, with farmers cultivating the same plots of land repeatedly to maximize yield. Aquaculture is not typically part of this system, and greenhouse farming is usually not associated with traditional subsistence methods.
Step-by-step explanation:
The methods used in intensive subsistence agriculture include a variety of labor-intensive techniques such as plowing, terracing, and irrigation. Not mentioned in the list but also essential to this form of agriculture is intercropping, which is the practice of planting different crops in proximity for pest control, pollination, providing habitat for beneficial creatures, maximizing the use of nutrients, and other synergistic growth interactions. Intensive agriculture is characterized by the repeated cultivation of the same plots of land to maximize yield and involves a close attention to the land with manual labor or the use of animals.
Crop rotation is another method used in intensive subsistence agriculture. This technique involves the sequential cultivation of different crops on the same land to maintain soil fertility and health, and to combat pest and weed pressure. Greenhouse farming could potentially be used in intensive subsistence systems, especially in regions with harsh climates, but it is not typically associated with traditional subsistence methods due to the technology and infrastructure required. Aquaculture, which is the farming of aquatic organisms such as fish, crustaceans, mollusks, and aquatic plants, does not typically fall under the category of intensive subsistence agriculture as it relates to water ecosystems rather than land.
Overall, intensive subsistence agriculture is characterized by high labor input and is practiced in areas where the population density is high, and the amount of arable land is limited. It focuses on growing enough food to sustain the immediate family or community, utilizing sophisticated and locally adapted techniques to make the most of the available land for crop production.