Use Efficiency Of Rice Research Articles

Nutrient expert ® rice - an alternative fertilizer recommendation strategy to improve productivity, profitability and nutrient use efficiency of rice in Nepal

Nepal is a major rice producer of South Asia, feeding more than 20 million people of the country and abroad. However, productivity and profitability of rice are low in Nepal compared to other regional countries. Large yield gaps exist between attainable and farmers’ yields and nutrient management is identified as one of the major reasons. Nutrient Expert ® (NE), a decision-support tool based on site-specific nutrient management (SSNM) principles has been validated and applied in many countries of Asia and Africa as new recommendation protocol for nutrient management in selected crops, including rice. Present study used NE ® Rice as nutrient management protocol in farmers’ fields across Terai and mid-hills regions of Nepal during 2014–2018. The study revealed that NE-based fertilizer recommendations resulted in increase in yield over 2.0 t.ha−1 (p ≤ 0.05) and double the profits compared to existing blanket fertilizer recommendation, and farmers’ fertilizer practice. Due to large variations in slope, altitude, soil, and management, performance of NE ® varied across locations. Its performance was better in Terai due to flat lands and less variations in soil types, compared to sloping lands and varied soils of mid-hills. NE tool provided adequate guidance to apply the required rate of fertilizer that matched the crop requirement and soil nutrient supply of each farmer fields. The novelty of the study is introduction of a dynamic fertilizer recommendation approach that can supplement the existing static blanket recommendation system. We conclude that Nutrient Expert ® - Rice can be considered as an effective tool for nutrient recommendation for rice in Nepal.

Effect of different levels of nitrogen and zeolite on nutrient uptake and nitrogen use efficiency in rice

Effect of different levels of nitrogen and zeolite on nutrient uptake and nitrogen use efficiency in rice

Natural allelic variation in a modulator of auxin homeostasis improves grain yield and nitrogen use efficiency in rice.

The external application of nitrogen (N) fertilizers is an important practice for increasing crop production. However, the excessive use of fertilizers significantly increases production costs and causes environmental problems, making the improvement of crop N-use efficiency (NUE) crucial for sustainable agriculture in the future. Here we show that the rice (Oryza sativa) NUE quantitative trait locus DULL NITROGEN RESPONSE1 (qDNR1), which is involved in auxin homeostasis, reflects the differences in nitrate (NO3-) uptake, N assimilation, and yield enhancement between indica and japonica rice varieties. Rice plants carrying the DNR1indica allele exhibit reduced N-responsive transcription and protein abundance of DNR1. This, in turn, promotes auxin biosynthesis, thereby inducing AUXIN RESPONSE FACTOR-mediated activation of NO3- transporter and N-metabolism genes, resulting in improved NUE and grain yield. We also show that a loss-of-function mutation at the DNR1 locus is associated with increased N uptake and assimilation, resulting in improved rice yield under moderate levels of N fertilizer input. Therefore, modulating the DNR1-mediated auxin response represents a promising strategy for achieving environmentally sustainable improvements in rice yield.

A genome-wide association study reveals the quantitative trait locus and candidate genes that regulate phosphate efficiency in a Vietnamese rice collection.

The crucial role of phosphate (Pi) for plant alongside the expected depletion of non-renewable phosphate rock have created an urgent need for phosphate-efficient rice varieties. In this study, 157 greenhouse-grown Vietnamese rice landraces were treated under Pi-deficient conditions to discover the genotypic variation among biochemical traits, including relative efficiency of phosphorus use (REP), relative root to shoot weight ratio (RRSR), relative physiological phosphate use efficiency (RPPUE), and relative phosphate uptake efficiency (RPUpE). Plants were grown in Yoshida nutrient media with either a full (320μM) or a low Pi supply (10μM) over six weeks. This genome-wide association study led to the discovery of 31 significant single nucleotide polymorphisms, 18 quantitative trait loci (QTLs), and 85 candidate genes. A common QTL named qRPUUE9.16 was found among thethree investigated traits. Some interesting candidate genes, such as PLASMA MEMBRANE PROTEIN1 (OsPM1), CALMODULIN-RELATED CALCIUM SENSOR PROTEIN 15 (OsCML15), phosphatases 2C (PP2C), STRESS-ACTIVATED PROTEIN KINASE (OsSAPK2), and GLYCEROPHOSPHORYL DIESTER PHOSPHODIESTERASES (GDPD13), were found strongly correlated to the Pi starvation. RNA sequencing transcriptomes revealed that 45 out of 85 candidate genes were significantly regulated under Pi starvation. Furthermore, nearly two-thirds of genotypes did not possess the OsPsTOL1 gene; however, no significant difference was observed in response to Pi deficiency between genotypes with or without this gene, suggesting that other QTLs in rice may resist Pi starvation. These results provide new information on the genetics of nutrient use efficiency in rice and may potentially assist with developing more phosphate-efficient rice plants.

Non‐flooding rice yield response to straw biochar and controlled‐release fertilizer

AbstractThe non‐flooding plastic film‐mulching cultivation (NFMC) is an important water‐saving rice (Oryza sativa L.) production technique for mountainous areas. Several studies indicated that this promising production system had positive effects on rice growth compared with the traditional flooding method. However, two obvious disadvantages need to be modified for its wider application: technical difficulties for mid‐season application of fertilizer and the observed loss of soil C. The solution for these problems may lead to enhanced and more sustainable rice production under NFMC conditions. A 2‐yr field experiment was conducted to evaluate the effects of combining straw biochar and controlled‐release urea with the NFMC system. The experimental design included two treatments of traditional flooded cultivation: (a) no N fertilizer; (b) urea alone; and four treatments under NFMC conditions: (a) no N fertilizer; (b) urea alone; (c) controlled‐release urea + urea; (d) a combination of straw biochar and controlled‐release urea + urea. Compared to a basal application of urea, controlled‐release urea plus urea together with straw biochar significantly increased rice grain yield and effective panicles. It also increased total biomass accumulation, the greenness of the leaves (SPAD value) and improved recovery efficiency of applied N. Our results show that the combination of controlled‐release urea and straw biochar can increase yield and N use efficiency of rice under NFMC conditions.

Nitrogen management practices for improving yield and nitrogen use efficiency in rice (Oryza sativa)

A field experiment was conducted on rice (Oryza sativa L.) during kharif season of 2017 at Crop Research Centre of Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut (U P) to assess the nitrogen (N) use efficiency and performance of rice under different nitrogen management practice. Management practices included N levels with modified application through leaf colour chart (LCC) and chlorophyll meter (SPAD). The study shows that treatment T6 (LCC (50 kg N/ha) with basal N @50 kg/ha)gave highest yield and N-use efficiency which were comparable to T9 (SPAD (67 kg N/ha) with basal N @33 kg/ha). The total biological yield (grain + straw) of rice was significantly higher in T6 (114.4 q/ha) as compared to control (66.9 q/ha). The SPAD and LCC-treated plot showed higher N-use efficiency in rice over fixed-scheduling N treatments. Highest N content(1.88% (grain) and 0.76% (straw)) and uptake (128.14 kg/ha) was recorded in T6 treatmentin all stages (tillering, PI and harvest) which was comparable with T8 and T9 treatment.

Physiological and biotechnological approach to improve water use efficiency in rice (Oryza sativa L.): Review

Rice is the widely cultivated cereal crop in the world. But low water use efficiency of rice (Oryza sativa L.) led rice cultivation more water expensive. Due to the climate change, drought and high temperature are the major environmental stress experienced by the plants. In this situation to sustain the yield of rice under limited water consumption is the major concern. Therefore physiological, biotechnological and agronomical approaches are adopted to improve water use efficiency (WUE) of rice. This review focused more about physiological and biotechnological approach to improve water use efficiency of rice.

Effect of urea briquettes deep placement on yield and nitrogen use efficiency of rice

Effect of urea briquettes deep placement on yield and nitrogen use efficiency of rice

Natural Diversity in Stomatal Features of Cultivated and Wild Oryza Species

BackgroundStomata in rice control a number of physiological processes by regulating gas and water exchange between the atmosphere and plant tissues. The impact of the structural diversity of these micropores on its conductance level is an important area to explore before introducing stomatal traits into any breeding program in order to increase photosynthesis and crop yield. Therefore, an intensive measurement of structural components of stomatal complex (SC) of twenty three Oryza species spanning the primary, secondary and tertiary gene pools of rice has been conducted.ResultsExtensive diversity was found in stomatal number and size in different Oryza species and Oryza complexes. Interestingly, the dynamics of stomatal traits in Oryza family varies differently within different Oryza genetic complexes. Example, the Sativa complex exhibits the greatest diversity in stomatal number, while the Officinalis complex is more diverse for its stomatal size. Combining the structural information with the Oryza phylogeny revealed that speciation has tended towards increasing stomatal density rather than stomatal size in rice family. Thus, the most recent species (i.e. the domesticated rice) eventually has developed smaller yet numerous stomata. Along with this, speciation has also resulted in a steady increase in stomatal conductance (anatomical, gmax) in different Oryza species. These two results unambiguously prove that increasing stomatal number (which results in stomatal size reduction) has increased the stomatal conductance in rice. Correlations of structural traits with the anatomical conductance, leaf carbon isotope discrimination (∆13C) and major leaf morphological and anatomical traits provide strong supports to untangle the ever mysterious dependencies of these traits in rice. The result displayed an expected negative correlation in the number and size of stomata; and positive correlations among the stomatal length, width and area with guard cell length, width on both abaxial and adaxial leaf surfaces. In addition, gmax is found to be positively correlated with stomatal number and guard cell length. The ∆13C values of rice species showed a positive correlation with stomatal number, which suggest an increased water loss with increased stomatal number. Interestingly, in contrast, the ∆13C consistently shows a negative relationship with stomatal and guard cell size, which suggests that the water loss is less when the stomata are larger. Therefore, we hypothesize that increasing stomatal size, instead of numbers, is a better approach for breeding programs in order to minimize the water loss through stomata in rice.ConclusionCurrent paper generates useful data on stomatal profile of wild rice that is hitherto unknown for the rice science community. It has been proved here that the speciation has resulted in an increased stomatal number accompanied by size reduction during Oryza’s evolutionary course; this has resulted in an increased gmax but reduced water use efficiency. Although may not be the sole driver of water use efficiency in rice, our data suggests that stomata are a potential target for modifying the currently low water use efficiency in domesticated rice. It is proposed that Oryza barthii can be used in traditional breeding programs in enhancing the stomatal size of elite rice cultivars.

Increasing nitrogen use efficiency in rice through fertilizer application method under rainfed drought conditions in Nepal

Nitrogen (N) is the most important yield-limiting plant nutrient. Despite various measures available for improvement of N management, nitrogen use efficiency (NUE) is still very low in rice (Oryza sativa L.), particularly under rainfed conditions. A field experiment was conducted at the Regional Agricultural Research Station, Banke, Nepal, during the rainy seasons of 2017 and 2018 to study the effects of nitrogen application method on NUE and grain yields across different varieties. The field experiment was laid out in a split-plot design, consisting of three rice varieties—Arize 6444, Radha-4, and Sukkha Dhan-3—as the main plots and five fertilizer treatments in sub-plots, and replicated thrice. The five fertilizer treatments included control (0 kg N ha−1), broadcast prilled urea at 78 kg N ha−1 and 100 kg N ha−1, and deep placement of prilled urea and briquetted urea at 78 kg N ha−1. Both rice variety and fertilizer treatment had a significant (p < 0.05) effect on grain yield. The hybrid variety (Arize 6444) increased grain yield by 23% compared to Sukkha Dhan-3 (4.9 Mg ha−1). Deep-placed briquetted urea increased grain yield by 21–23% (6.7 Mg ha−1) compared to broadcast and deep-placed prilled urea. A higher grain yield for briquetted urea positively correlated (r = 0.43) with the number of tillers per hill. Deep-placed briquetted urea increased NUE (apparent N recovery, agronomic NUE, partial factor productivity of N, and physiological efficiency by 44%, 40%, 34%, and 3%, respectively), while reducing ammonia volatilization by 57% compared to the current recommended rate of broadcast prilled urea. Our results confirm that deep placement of briquetted urea significantly increases grain yields and NUE of rainfed rice.

Nitrogen forms affect the root characteristic, photosynthesis, grain yield, and nitrogen use efficiency of rice under different irrigation regimes

AbstractAppropriate irrigation methods and N management can effectively increase the yield and N efficiency of rice (Oryza sativa L.). A soil‐grown experiment was conducted in 2018 and 2019 using Liangeng 7 with different N forms (NH3–N, NH4+ and NO3− mixed 50:50 [50:50], and NO3–N), as well as three irrigation regimes (submerged irrigation [0 kPa], alternate wetting and moderate drying [−20 kPa], and alternate wetting and severe drying [−40 kPa]). Results showed that yield and N agronomic efficiency were maximized at the alternative wetting and moderate dying treatment with NH4NO3 mixed among all treatments. Nitrogen forms in different irrigation regimes had different effects on root characteristic and leaf photosynthesis rate. In submerged irrigation, NH3–N treatment improved root morphology, increased the activities of NH3 assimilation enzymes in roots, and promoted root oxidation and leaf photosynthesis rate at different growth stages compared with other N forms. By contrast, moderate drying interacted with 50:50 and significantly enhanced root length, average root diameter, root volume, root tips, and root oxidation activity and promoted C and N metabolism in root and photosynthesis rate of leaves compared with other N forms under alternate wetting and drying irrigation. Multiple regression analysis showed that root length, the glutamate synthase (GOGAT) activity of roots, and the photosynthetic rate of leaves closely related with high rice yield and efficient N utilization. All these results suggested that improved root morphology and physiology activity, enhanced C and N metabolism, and increased leaf photosynthesis rate through the appropriate regulation of irrigation‐regime interaction with N forms can help to increase the grain yield and N agronomic efficiency of rice.

P-dipping of rice seedlings increases applied P use efficiency in high P-fixing soils

Applied phosphorus (P) use efficiency is generally low due to the low mobility of P in soil and its affinity to form insoluble complexes. Localized P application nearby the root zone is a potential approach to overcome this issue in crop production. However, the interaction with soil conditions is little understood, which results in less effective application of this approach. Using root-box experiments and changing P-retention capacity of soils, we revealed that applied P use efficiency of rice can be substantially improved by dipping seedlings in P-enriched slurry at transplanting (P-dipping) even in highly P-fixing soils. Spatial analysis of soluble P in soils indicated that P-dipping creates a P hotspot because the P-enriched slurry is transferred with seedling roots. The P hotspot could have induced vigorous surface root and facilitated further P uptake from the spot. In contrast, the effect of conventional P incorporation depended on P-retention capacity of soils; no increases in soluble P content in soils or plant P uptakes were observed when P-retention capacity was high. Our finding of significant interaction between localized P application and a specific soil property should help improving applied P use efficiency and achieving sustainable rice production against depleting P fertilizer resources.

Doubling farmers income through system of rice intensification and comparative analysis of SRI and conventional method of rice cultivation in Theni district of Tamil Nadu

On farm demonstrations on Green manure-System of Rice Intensification (GM-SRI) were carried out in 10 hectares farmer’s fields in Jeyamangalam, Silvarpatti and Melavadipatti villages of Varaganadhi sub basin, Periyakulam Block, Theni district of Tamil Nadu during September 2018 – February 2019 under Tamil Nadu Irrigated Agriculture Modernization Project (TN-IAMP).Totally twenty one demonstrations were laid out in the sub basin villages. Green manure – System of Rice Intensification (GM-SRI) and conventional method of rice cultivation were the two rice cultivation methods compared in the farmers field. Results revealed that adoption of Green manure followed by System of Rice Intensification recorded higher yield attributes of rice viz., number of productive tillers m-2, length of panicle and numbers of grains panicle-1 and there by increased grain yield and straw yield. GM-SRI resulted in 17.0 per cent yield increment than the conventional method of cultivation besides the substantial water saving of 29 per cent and 7.7 kg/ha mm water use efficiency. Higher grain yield coupled with substantial water saving resulted in higher Water Use Efficiency of rice under Green manure - SRI method. Higher gross income, net profit and benefit cost ratio were also associated with Green manure-SRI than conventional method of rice cultivation. The cost of cultivation was comparatively lesser in Greenmanure - SRI which resulted in gaining an additional net profit of Rs. 53643 ha-1 in Greenmanure - SRI as compared to conventional method of rice cultivation.

A push, and a pull, to enhance nitrogen use efficiency in rice.

A push, and a pull, to enhance nitrogen use efficiency in rice.

Association Analysis of Growth Characteristics, WUE, and RUE of Rice in Cold Region Under Different Irrigation Patterns

In order to clarify the relationship between growth characteristics of rice, WUE and RUE, the apriori algorithm was used to mine association rules for rice indicators data. In this study, the experiments set up control irrigation, wet irrigation and flood irrigation from May to September in 2017 and 2018, which were carried out in Qing’an Irrigation Experimental Center in the semi-humid area of Heilongjiang Province, China. Because of the difficulty in data collection and the long test period during the study, insufficient data could not be collected for data mining. Therefore, before using the apriori algorithm, the original data was augment by using the generative adversarial network. Correlation analysis of indicators data showed that the correlation among the indicators of rice under the three irrigation patterns was very close. Height, stem diameter and other indicators interacted with each other, which in turn affected the yield, water and radiation use efficiency of rice. Water use efficiency and dry matter got the highest value of correlation analysis under control irrigation was 0.97, yield and dry matter got the second highest value was − 0.95. Yield and height got the highest value of correlation analysis under wet irrigation was 0.94, dry matter and seed setting rate got the second highest value were 0.90, respectively. Yield and height got the highest value of correlation analysis under flood irrigation was − 0.90, stem diameter and dry matter got the second highest value of correlation analysis was 0.85. The results of association analysis combined with three irrigation patterns indicated that the association between seed setting rate, height, leaf area index, dry matter, yield and water use efficiency was the closest. The increase of height, stem diameter, dry matter and seed setting rate can promote rice yield and water use efficiency, while reducing leaf area index and 1000-grain weight will have a negative impact on yield.

Influence of nitrogen on the growth and use efficiency of rainfed lowland rice in northwest Ethiopia

Rice productivity in Fogera Plain of Ethiopia is low due to poor soil nitrogen management. A field experiment was conducted for two years during the main cropping seasons of 2017 and 2018 in Fogera Plain to study the effect of N fertilizer rates and application methods on productivity and nitrogen use efficiency of lowland rice. The experiment was conducted using a factorial arrangement of six levels of N rates (46, 92, 138, 184, 230, and 276 kg N ha−1) and two levels of application methods (farmers’ practice and mud-balls form) with the control, laid out in a randomized complete block design (RCBD) in three replicates. Results revealed that N rates had a significant effect on the growth, biomass and grain yields, and N use efficiency of rice. Interaction effects of application methods by N rates had only a significant effect on N use efficiency of rice. Generally, rain-fed lowland rice grain yield (4.2–5.2 tons ha−1) positively responded to fertilizer N rates from 138 to 276 kg ha−1. Nitrogen use efficiency was highest at the low and intermediate levels of N and low on highest levels of N. From this study, mud-balls making Urea is a tedious and labor intensive work. Rather, hence, nitrogen use efficient methods of Urea supergranule tablet should be used based on the recommended 276 kg ha−1 nitrogen rate to exploit more grain yield of rain-fed lowland rice without yield penalty in Fogera Plain.

Alkaline hydrolyzable nitrogen and properties that dictate its distribution in paddy soil profiles

Nitrogen (N) is a key nutrient for rice production, and its bioavailability in paddy soils is strongly coupled to soil organic matter (SOM) cycling. A better understanding of potentially available N forms in soil, such as alkaline hydrolyzable N (AH-N), and their depth distribution will support the development of best management practices to improve the N use efficiency of rice while minimizing adverse environmental effects. Fifteen rice (Oryza sativa L.) fields from Southern Brazil were selected, and stratified soil samples were taken to a depth of 60 cm before crop establishment. Selected soil physical and chemical properties were analyzed to evaluate their relationships with AH-N contents in the soil profile. The AH-N contents below 20 cm varied extensively (increased, reduced, or constant) compared with that above 20 cm. Although clay and clay + silt contents were highly correlated to AH-N for some soils, the major property dictating AH-N distribution by depth was total N (TN), as the correlation between TN and AH-N was mainly by direct effect. The proportion of TN recovered as AH-N across sites and depths presented high amplitude, and thus AH-N was not a constant N pool across depths, indicating that AH-N can be affected by soil management practices even when TN showed no major changes. The distinct distribution of AH-N across soil sampling sites and depths indicates that depths greater than 20 cm should be considered when calibrating the AH-N index for N fertilizer recommendations for flooded rice in Southern Brazil.

Survey and Mapping of P Nutrient Status on Paddy Land in Aek Simare Irrigation Area, Laguboti District, Toba Samosir Regency, Northern of Sumatera, Indonesia

The research aims to a mapping of nutrient status available phosphate and total phosphate in the Aek Simare Irrigation Area Laguboti District Toba Samosir Regency. This research was conducted at the Testing Laboratory of Agricultural Technology Research Center in North Sumatera Province. Which began in Mey to June 2019. The method used is the Free Grid Survey detailed level survey and analysis of nutrient data available phosphate by Bray I method, total phosphate by acid destruction method, and then interpret to the map nutrient status. The result of research showing that status available phosphate classified by 3 statuses such as medium (3,99 ha), high (44,26 ha), and very high (71,75 ha). Total phosphate classified in 4 nutrient status such as low (0,004 ha), medium (67,37 ha), high (45,316 ha) and very high (7,31 ha). Available phosphate and total phosphate are very related to increasing rice production in the Aek Simare Irrigation Area Laguboti District Toba Samosir Regency, Northern of Sumatra, Indonesia REFERENCES BPS Toba Samosir. 2018. Laguboti Subdistrict in Figures 2018. Central Bureau of Statistics of Toba Samosir Regency. De Datta, S.K., Buresh, R.J., Mamaril, C.P. 1990. Increasing Nutrient Use Efficiency in Rice with Changing Needs. Kluwer Academic Publishers. Netherland. Center for Soil and Agro-Climate Research (PUSLITANAK). 1983. Assessment Criteria of Soil Chemical Properties. Center for Soil and Agro-climate Research. Bogor Agriculture Department. 2007. References Determination of Fertilizer Recommendations N, P, and K on Specific Rice Fields Location. As an Appendix of Permentan Number40 / Permentan / OT.140 / 04/2007. Sanchez, P. A. 1993. Nature and Tropical Management 2. Translation of Amir Hamzah. ITB. Bandung. Agricultural Land Resources. Bogor, 30 November - 1 December 2010. Husnain. 2010. Loss of Nutrients Due to Burning Rice Straw and Potential of Environmental Pollution. Soil Research Institute. Published Paper at the Proceedings of the National Seminar. Soil Research Institute. Published Paper at the Proceedings of the National Seminar Agricultural Land Resources. Bogor, 30 November - 1 December 2010.

Phosphorus (P) use efficiency in rice is linked to tissue-specific biomass and P allocation patterns

Phosphorus (P) is a non-renewable resource which may be depleted within next few decades; hence high P use efficiency is need of time. Plants have evolved an array of adaptive mechanisms to enhance external P acquisition and reprioritize internal utilization under P deficiency. Tissue specific biomass and P allocation patterns may affect the P use efficiency in plants. six rice cultivars were grown in solution culture for 20 days and then were divided into two groups to receive either adequate P or no P that were harvested at 30, 40 and 50 days. Plants were dissected into various tissues/organs. Two rice cultivars viz Super Basmati (P-inefficient) and PS-2 (P-efficient) were grown in soil with no or 50 mg P kg−1 soil till maturity. Rice cultivars PS-2 and Basmati-2000 had higher P uptake, utilization efficiency and internal remobilization than other tested cultivars after P omission. Young leaves and roots were the major sinks while stems and mature leaves were the sources of P during P omission. In conclusion, biomass allocation and P accumulation among various tissues and P remobilization were major factors responsible for P efficiency.

Nitrogen fertiliser and establishment method affect growth, yield and nitrogen use efficiency of rice under alternate wetting and drying irrigation

AbstractSustainable rice production through selection of best suitable cultivar, water‐efficient crop establishment method and optimum nitrogen (N) management practice is needed to feed the growing world population. Two polyhouse experiments were conducted to evaluate the response of rice to different rates and schedules of N application under different establishment methods subjected to alternate wetting and drying (AWD) irrigation. In the first experiment, the response of two rice cultivars (Pathumthani 1, RD57) under three establishment methods (transplanting [TP], wet direct seeding [WDS], dry direct seeding [DDS]) and five N rates (0 [N0], 30 [N30], 60 [N60], 90 [N90], 120 [N120] kg ha−1) was evaluated. The second experiment consisted of the same cultivars and establishment methods, but with four N application schedules (T1: 100% at basal; T2: 75% + 25% at basal and at active tillering, respectively; T3: 50% + 25% + 25% at basal, at active tillering and at panicle initiation, respectively; and T4: 25% + 25% + 25% + 25% each at basal, at active tillering, at panicle initiation and at early flowering or just before heading starts) applied at the rate of N60 kg ha−1. Plants were maintained under AWD irrigation (soil was saturated by applying water whenever soil water potential drops to −5 kPa during the implementation period) in both experiments. RD57 performed better than Pathumthani 1 having higher shoot dry matter, panicle number, grain yield, total N uptake and apparent N recovery efficiency. TP gave better response than WDS and DDS regardless of cultivars. Application of N120 resulted in better growth, yield and its components and total N uptake regardless of establishment methods and cultivars. Increasing N rate decreased N use efficiency (NUE). Scheduling the interval of N application to two or three times (T2 or T3) for RD57 and Pathumthani 1, respectively, provided overall better results, and could be recommended for the tested rice cultivars. An optimal N rate and selection of critical growth stages for N application would be very effective for maximising yield and NUE under the water‐saving cultivation technique of AWD irrigation.