Improving Irrigated Lowland Rice Water Use Efficiency under Saturated Soil Culture for Adoption in Tropical Climate Conditions

Abstract

Saturated soil culture is one of the water saving techniques that can improve water productivity. However, it is either less implemented or adopted because it consumes more time and energy. Therefore, an experiment was conducted to determine the effective water depth that can keep soil moisture close to saturation for a commonly practiced irrigation interval, combined with a rainfall pattern for increasing water productivity. The design was a randomized complete block with three replications and four water treatments representing 120% (T120), 180% (T180), 240% (T240), and 300% (T300) of soil saturation or the application of 2, 3, 4 and 5 cm water depth. The results showed that the application of 3 cm was the effective depth. It decreased plant height, tiller number, chlorophyll content, and panicle number per hill by 12.37%, 20.84%, 7.59%, and 70.98%, respectively. The decrease of these parameters is followed by total recovery due to effective rainfall contribution, which led to low yield sacrifice (6% of reduction) and 40% of water saving. We argue that weekly application of a 3 cm water depth and matching crop needed-water period with the onset of rainfall may be implemented and recommended as suitable saturated soil culture practice for rice production in high water demand conditions.

Impact of Water Management on Rice Varieties, Yield, and Water Productivity under the System of Rice Intensification in Southern Taiwan

“…In addition, root volume was heaviest in plants grown under three-day intermittent irrigation intervals. Greater root volume and longer roots is regarded as an adoption measure for plants to maximize water capture and access water at grater depths [36,51]. Even though root dry biomass produced similar results, it was highest under intermittent irrigation of three-day interval, which could indicate a strong water and nutrient absorption capacity translating into high grain production.…”

“…The 20 uppermost fully expanded leaves were selected from the randomly selected hills with three observations made per leaf for chlorophyll content analysis among treatments. Analysis of leaves sampling patterns done by [36,37] showed that at least four leaves per plot are needed, with several observations per leaf. Then, the average of these observations was used to represent the leaf chlorophyll content.…”

Influence of Transplanting Age on Paddy Yield under the System of Rice Intensification

“…However, the processes of transplanting younger seedlings should be carried out in a well-designed and levelled field to avoid irregular distribution of irrigation water that may lead to the submergence of the transplanted seedlings that consequently result to premature crop failure [10]. These and many technological aspects enhance sustainable high yield per unit area of rice production [11]. However, this technology requires high reliability of water so as to facilitate physiological and nutritional maintenance of the fields [9].…”

Impact of water management on root morphology, growth and yield component of lowland rice varieties under the organic system of rice intensification

“…In addition, the root volume weight of intermittent irrigation was higher too. Greater root volume and longer roots are regarded as an adoption measure for plants to maximize water capture and access water at greater depths (Ascha, 2005 ;Kima et al, 2014).…”