Agriculture Reference
In-Depth Information
9.2 Aerobic Rice
Aerobic rice requires the same amount of nutrients as flooded rice, but in the former
case, there is a problem of P availability, due to its fixation with other elements
(Goldstein
1986
). In acidic soils (pH
6.0), most crops suffer from P deficiency
due to the ability of soil P to form complexes with Al and Fe and become insoluble
under aerobic conditions (Sanchez and Uehara
1980
). There is insufficient infor-
mation available on the cultivation of aerobic rice especially in terms of its nutrient
management. On the other hand, there are several reports where potential PSB has
been used for the management of P-deficient soils (Panhwar et al.
2012
; Vazquez
et al.
2000
). The use of these beneficial bacteria enhances the sustainable crop
production and reduces the dependency on costly imported phosphatic fertilizers.
Although several findings are available on the beneficial effects of PSB in many
upland crops, there is still inadequate information available on the use of PSB as
vital agents for P fertilizer management (especially phosphate rock) in aerobic rice.
Hence, the present study was focused on identifying and selecting some biologi-
cally efficient PSB strains for improving the uptake of P and simultaneously
enhancing the growth of aerobic rice.
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9.2.1 Water Requirement of Aerobic Rice
Aerobic rice reduces total water use by 27-51 % and improves water productivity
by 32-88 % and can decrease water loss due to seepage, percolation, and evapo-
ration (Bouman et al.
2005
). Previous studies in the Philippines and northern China
have shown that aerobic rice required 30-50 % less water as compared to flooded
systems with 20-30 % lower yields (4.7-5.3 tons ha
1
) than Wetland rice (Bouman
et al.
2006
). Due to this, the cultivation of aerobic rice is increasing very rapidly in
both temperate and tropical regions in China (Wang et al.
2002
).
9.2.2 Nutrient Management in Aerobic Rice
Aerobic rice can be grown in non-flooding soils and can tolerate flooding, thus it is
ideally suited for both flood-prone and drought-prone areas. In aerobic rice, the
focus of researchers is more on water use and yields (Bouman et al.
2006
); however,
little attention is paid on fertilizer response and nutrient use efficiency. The transfer
from flooding to non-flooding (aerobic) soil conditions may alter soil water status,
soil aeration, and nutrient availability (Timsina and Connor
2001
). In addition, the
research findings suggest that N and P deficiency in aerobic crops is quite common
(Fageria and Breseghello
2001
). For availability of P, the mechanism is different in
aerobic condition compared to anaerobic rice cultivation system, and P deficiency
