What is the difference between aerobic rice and upland rice?

Upland rice is grown in rainfed, naturally well-drained soils with bunded or unbunded fields without surface water accumulation. The general perception about the upland environment is that it is drought-prone, usually sloping land with erosion problems, and has soils with both poor physical and chemical properties. Farmers in these environments are among the poorest and usually can not afford to apply (many) external inputs such as fertilizers. Upland rice varieties are mostly grown as a low-yielding subsistence crop to give stable yields under the adverse environmental conditions of the uplands. Upland rice varieties are drought tolerant, but have a low yield potential and tend to lodge under high levels of external inputs such as fertilizer and supplemental irrigation.

The aerobic rice system is targeted at more favorable environments where farmers can afford to buy external inputs such as fertilizers and have access to supplementary irrigation if rainfall is not sufficient. Achieving high yields under relatively favorable aerobic soil conditions requires new varieties of “aerobic rice” that combine the drought-resistant characteristics of upland varieties with the high-yielding characteristics of lowland varieties. In essence, aerobic rice can be seen as “favorable” or “high yielding” upland rice. The reason for the introduction of a new term was the need to dissociate the envisioned relatively high-yielding production system from the general perception of extremely harsh and unfavorable conditions of “the uplands”.