The drought response of lowland rice to crop establishment practices and N-fertilizer sources uri icon

abstract

  • Increasing drought resistance and nutrient availability to the plant is important for increasing yields in rainfed lowland rice. This study investigated the effects of crop establishment and controlled-release fertilizers on drought stress responses and nitrogen uptake of rice (Oryza sativa L.) cv. PSBRc14 grown on a clayey loam Vertic Tropaquept in a split-split-plot field experiment. The main plots were two water treatments (well-watered and drought-stressed for 20 days from panicle initiation). The subplots comprised of three crop establishment methods. In the sub-subplots, prilled urea was compared with Polyon 12 and POC-S 120. Drought prolonged crop maturity by about 20 days and greatly reduced grain yield but not the total biomass and total N uptake. Dry-seeded rice had a lower yield in the well-watered treatment but higher yield in the stress treatment compared with transplanted and wet-seeded rice. The higher yield of dry-seeded rice under stress could be related to its significantly higher root length density, higher root-shoot ratio, and more uniform root distribution with respect to soil depth, and higher available soil moisture in the root zone during the stress period. Under the well-watered condition, yields in all fertilizer treatments were comparable. In the stress treatment, Polyon 12 produced the lowest yield probably because of the mismatch between drought-induced prolongation of crop duration and the release period of Polyon 12. (C) 2002 Elsevier Science B.V. All rights reserved.

publication date

  • 2002
  • 2002
  • 2002