|Book Title:||ADVANCES IN AGRONOMY, VOL 111|
|Book Group Author:|
About 90% of rice is produced and consumed in Asia, where the demand for rice is on the increase due to increasing population. Rice is a semiaquatic plant and grows well under lowland flooded anaerobic conditions. Most high yielding varieties yielding 6-8 t/ha have been developed to suit such conditions. However, there are large areas, where rice is grown under upland aerobic conditions with drought tolerant varieties that yield about 1 t/ha or a little more. Aerobic rice varieties are now being developed that have drought tolerance as well as high yielding ability. Aerobic rice system (ARS) is a new production system in which rice is grown under nonpuddled, nonflooded, and nonsaturated soil conditions. The expected yields in ARS are somewhat lower than those obtained under lowland flooded conditions, but double or treble of that obtained under upland conditions. However, ARS has been successful in cool temperate regions. For warm humid rice growing regions, a partial aerobic rice system (PARS) may be a more plausible alternative. PARS technologies are available. Some available results, however, show a decline in rice yield over years in ARS and suggest that ARS may not be sustainable over a long period. The factors responsible appear to be N, P, K, Fe, and Zn deficiencies, weeds and soil-borne root-knot nematodes. Some of these problems can be overcome by introducing legume such as soybean in ARS/PARS. ARS/PARS call for application of herbicides and namaticides, which are going to add additional burden on poor Asian farmers. In addition, farmers have to be trained in the careful and proper use of herbicides and nematicides. Herbicides have also been associated with environmental pollution problems.
|Journal ISO:||Adv. Agron.|
|Publisher:||ELSEVIER ACADEMIC PRESS INC|
|Source:||Web of Science|