scholarly journals Spatial Variations in Water Availability, Soil Fertility and Grain Yield in Rainfed Lowland Rice: A Case Study from Savannakhet Province, Lao PDR

2011 ◽  
Vol 14 (2) ◽  
pp. 184-195 ◽  
Author(s):  
Thavone Inthavong ◽  
Shu Fukai ◽  
Mitsuru Tsubo
Keyword(s):  
Soil Fertility ◽  
Grain Yield ◽  
Water Availability ◽  
Lao Pdr ◽  
Spatial Variations ◽  
Lowland Rice ◽  
Rainfed Lowland

Root Growth and Yield Response of Rainfed Lowland Rice to Planting Method

1987 ◽  
Vol 23 (3) ◽  
pp. 305-313 ◽  
Author(s):  
P. K. Sharma ◽  
S. K. De Datta ◽  
C. A. Redulla
Keyword(s):  
Root Growth ◽  
Grain Yield ◽  
Water Table ◽  
Sandy Loam ◽  
Lowland Rice ◽  
Yield Response ◽  
Clay Loam ◽  
Transplanted Rice ◽  
Rainfed Lowland ◽  
Loam Soil

SUMMARYField experiments were conducted on two soils (clay loam and sandy loam) with varying texture and water table depth to study the effects of two planting methods (dry seeding and transplanting) on the root growth and grain yield of rainfed lowland rice. About 75% of the roots were found in the top 10 cm soil. Root length density at the flowering stage and grain yield in the sandy loam soil, with a water table deeper than 1.5 m, were less in dry-seeded than in transplanted rice, probably because of the greater moisture stress in dry-seeded rice between late tillering and harvest. In the clay loam soil, with the water table mostly at the soil surface, there was no difference in grain yield between dry-seeded and transplanted rice.

Soil clay content, rainfall, and toposequence positions determining spatial variation in field water availability as estimated by a water balance model for rainfed lowland rice

2012 ◽  
Vol 63 (6) ◽  
pp. 529 ◽  
Author(s):  
T. Inthavong ◽  
M. Tsubo ◽  
S. Fukai
Keyword(s):  
Water Balance ◽  
Water Availability ◽  
Clay Content ◽  
Lowland Rice ◽  
Balance Model ◽  
Yield Reduction ◽  
Growing Period ◽  
Rainfed Lowland ◽  
Soil Clay ◽  
Soil Clay Content

Drought is a major limiting factor for the production of rainfed rice in the Mekong Region. Thus, estimation of the length of growing period (LGP) based on estimation of the development of water deficit is essential for sound planning of agricultural development. A recently developed soil-water balance model was used to quantify the availability of water for rice crops and yield reduction due to water deficit. Field water availability is known to be largely affected by soil type and rainfall pattern, and their separate effects were investigated in this study of a spatial analysis of LGP, using inputs for rainfed lowland rice in Savannakhet province in central Laos. The analysis showed that the start of growing period (SGP) and end of growing period (EGP) were affected largely by geographical variations in rainfall and soil clay content, respectively. Also, the areas having relatively short LGP were generally associated with large yield reduction because of low water availability associated with coarse-textured soils. At local scale, field water availability varied from upper to lower positions of a sloping land (toposequence) in the rainfed lowland ecosystem of the Mekong region, causing variation in yield within the toposequence. Using the level of field water determined around flowering time at different toposequence positions in 45 farms, estimated yield reduction was compared in seven main rice-growing districts of the province. Variability of yield loss, associated with variation in water availability, was larger across the toposequence positions than across districts, showing the importance of local variability in determining yield in rainfed lowland rice. The present approach of a combination of simulation model and GIS is adopted for characterisation of the water environment for rainfed lowland rice in other parts of Laos, as well as in neighbouring Thailand and Cambodia.

scholarly journals Topographic Position Influences Water Availability in Rainfed Lowland Rice at Rajshahi, Northwest Bangladesh

2004 ◽  
Vol 7 (1) ◽  
pp. 101-103 ◽  
Author(s):  
Benjamin Samson ◽  
Ansar Ali ◽  
Mohammed Rashid ◽  
Mohammed Mazid ◽  
Len Wade
Keyword(s):  
Water Availability ◽  
Lowland Rice ◽  
Topographic Position ◽  
Rainfed Lowland

Comparative efficiency of different planting methods in intermediate deepwater (15–50 cm) rice

1987 ◽  
Vol 108 (3) ◽  
pp. 573-577 ◽  
Author(s):  
M. D. Reddy ◽  
B. C. Ghosh
Keyword(s):  
Grain Yield ◽  
Clonal Propagation ◽  
Lowland Rice ◽  
Comparative Efficiency ◽  
Planting Methods ◽  
Rainfed Lowland ◽  
Intermediate Deepwater

SummaryIn rainfed lowland rice areas of intermediate deepwater (15–50 cm), transplanting in greater depths of water (50–60 cm) with clonal tillers (double transplanting) from 20 or 40- to 50-day-old-transplanted crops of similar environment increased grain yield significantly compared with seedlings of the same age (60 or 80- to 90-day-old) from a nursery. The grain yield did not decrease significantly when the clonal tillers were removed at 20 or 40 days after transplanting compared with that of the undisturbed crop. The practice of double transplanting (clonal propagation) increased tiller production and the number of panicles, and the crop could tolerate better the greater depths of water and thereby give greater grain yield.

Genotypic performance in multi-location on-farm trials for evaluation of different on-station screening methods for drought-prone rainfed lowland rice in Lao PDR

2014 ◽  
Vol 160 ◽  
pp. 1-11 ◽  
Author(s):  
P. Xangsayasane ◽  
S. Fukai ◽  
J.H. Mitchell ◽  
B. Jongdee ◽  
D. Jothityangkoon ◽  
...  
Keyword(s):  
Lao Pdr ◽  
Lowland Rice ◽  
Screening Methods ◽  
Rainfed Lowland ◽  
On Farm
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