Cataloging factor of Water Accessibility, Management Practices and Grain Harvest for Deepwater Rice in South-east Asia

DOI

http://doi.org.in/10.9379-sf.ijals-122062-005-0081-x

AUTHOR AFFILIATION

* Graduate School of Bio resources, Mie University, Tsu, Mie, Japan **Faculty of Education, Saitama University, Saitama, Japan ***Faculty of Agricultural Technology, Rambhai Barni Rajabhat University, Muang, Chantaburi, Thailand

ABSTRACT

This study aimed to characterize rice area from the shallower (lower topo sequence of rain fed lowlands side to the deeper floating rice side in Northwest Cambodia during wet season rice (WSR) production in 2009 and 2010 for the yearly and spatial differences in field water conditions, management practices and grain yield. This area considered as deepwater rice (DWR) area was divided into three groups with (1) upper fields located near the National Road Number 5 (referred as ULR); (2) middle fields (referred as MLR and MFR where lowland rice (LR) and floating rice (FR) were planted, respectively); and (3) lower fields located near to the Lake (referred as LFR). Water came to the paddy fields from both the inundation from Tonle Sap Lake and rainfall in WSR 2009, but only from rainfall in WSR 2010. Water depths increased from upper to lower fields in 2009, while they were shallower and relatively similar between the field locations in 2010. Broadcasting time started earlier and harvesting time finished later in FR fields than in LR fields. The overall average grain yield for both years of 2009 and 2010 was low. The lowest yields were observed in MLR and MFR in 2009 as well as they were in MFR and LFR in 2010. Lower yield in WSR 2009 was mainly due to the water shortage at heading stage for both FR and LR, improper application of N fertilizer and insufficient weed management for LR, and late sowing for FR. Lower yield in WSR 2010 was mainly due to low water level for FR, low N fertilizer rate and insufficient weed management. This study identified important spatial and yearly variation in rice management and grain yield for farmers to cope with unpredictable flooding environments in DWR area.