Effects of differential availability of water on rice yields and farm practices in the vaca creek irrigation system, Nueva Ecija, [Philippines] 1985 dry season
1987
Bello, R.T.
The results of the analysis of variance revealed that intralateral yield variation was greater than the inter-lateral variation. Also, soil water requirements were significantly different among the laterals. Average yields declined with increasing amount of stress. Moreover, water inadequacy appeared directly related to the soil water requirements and the distance of the farm from the source. A three stage recursive equation model was developed to determine the water-nitrogen-yield relationships. The results showed that seepage and percolation and distance of the farms from the water source were the dominant factors affecting the occurrence of stress days. Nitrogen use, on the other hand, was significantly influenced by the amount of operating capital available to the farmer. Crop yield variation was explained largely by the variation in nitrogen use and duration of stress days. The results of the multiple regression analysis, suggest that water distribution problems may be present along the tertiaries in the upper section and along the laterals for the downstream portion. Systemwise, the incidence of stress days was attributed to maldistribution of water along the main and secondary canals.
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