Under the government of Democratic Kampuchea, great effort was made to build irrigation systems throughout the country. The results occasionally were notable, and in a few parts of the country farmers were able to grow two, and more rarely three, crops of rice per year. In some cases the works were poorly conceived and hastily built and soon collapsed. Most of those that survived were abandoned after 1979.

Under the traditional patterns of agriculture, planting normally begins in July or August, and the harvest period extends from November to January. The amount of rainfall, when there is little irrigation, determines the size and quality of the crop. Other food products include corn (maize), beans, soybeans, and sweet potatoes. The principal fruit crops, all of which are consumed locally, include oranges, bananas, and pineapple; these are supplemented by a variety of other tropical fruits, including breadfruit, mango, mangosteen, and papaya.

Fisheries and livestock are important components of the domestic economy. Fish in its various forms—fresh, dried, smoked, and salted—constitutes the most important source of protein in the Cambodian diet, and subsistence fishing is part of every farmer's activity. The annual freshwater catch includes perch, carp, lungfish, and smelts. Cattle, particularly water buffalo, are used principally as draft animals in the rice paddies and fields. Hog production has also played a large role in agriculture. Efforts to replenish the number of livestock—depleted by years of war—have been hampered by uncertain social conditions and the prevalence of animal diseases.

Until the mid-1970s, the vast majority of Cambodia's people inhabited the central lowland region, where the rural village was second only to the family as the basic social unit. The typical Cambodian village in those days was made up of ethnically homogeneous people and had a population of fewer than 300 persons. The village (phum) was part of a hamlet or community (khum) with which it shared one or more Buddhist temples (wat), an elementary school, and several small shops. Cambodian villages usually developed in a linear pattern along waterways and roads, but often houses also were dispersed through the countryside on largely self-contained paddy farms. Houses in Cambodia generally were built on wooden pilings and had thatched roofs, walls of palm matting, and floors of woven bamboo strips resting on bamboo joists. More prosperous houses, while still on pilings, were built of wood and had tile or metal roofs.