scholarly journals OPTIMIZING SYSTEM OF RICE INTENSIFICATION PARAMETERS USING AQUACROP MODEL FOR INCREASING WATER PRODUCTIVITY AND WATER USE EFFICIENCY IN RICE PRODUCTION

Author(s):  
Z. Katambara ◽  
F. C. Kahimb ◽  
W. B. Mbungu ◽  
R. Paul ◽  
M. Maugo ◽  
...  
2009 ◽  
Vol 45 (3) ◽  
pp. 275-286 ◽  
Author(s):  
LIMEI ZHAO ◽  
LIANGHUAN WU ◽  
YONGSHAN LI ◽  
XINGHUA LU ◽  
DEFENG ZHU ◽  
...  

SUMMARYField experiments were conducted in 2005 and 2006 to investigate the impacts of alternative rice cultivation systems on grain yield, water productivity, N uptake and N use efficiency (ANUE, agronomic N use efficiency; PFP, partial factor productivity of applied N). The trials compared the practices used with the system of rice intensification (SRI) and traditional flooding (TF). The effects of different N application rates (0, 80, 160 and 240 kg ha−1) and of N rates interacting with the cultivation system were also evaluated. Resulting grain yields with SRI ranged from 5.6 to 7.3 t ha−1, and from 4.1 to 6.4 t ha−1 under TF management. On average, grain yields under SRI were 21% higher in 2005 and 22% higher in 2006 than with TF. Compared with TF, SRI plots had higher harvest index across four fertilizer N rates in both years. However, there was no significance difference in above-ground biomass between two cultivation systems in either year. ANUE was increased significantly under SRI at 80 kg N ha−1 compared with TF, while at higher N application rates, ANUE with SRI was significantly lower than TF. Compared with TF, PFP under SRI was higher across all four N rates in both years, although the difference at 240 kg N ha−1 was not significant. As N rate increased, the ANUE and PFP under both SRI and TF significantly decreased. Reduction in irrigation water use with SRI was 40% in 2005 and 47% in 2006, and water use efficiency, both total and from irrigation, were significantly increased compared to TF. With both SRI and TF, the highest N application was associated with decreases in grain yield, N use efficiency and water use efficiency. This is an important finding given current debates whether N application rates in China are above the optimum, especially considering consequences for soil and water resources. Cultivation system, N rates and their interactions all produced significant differences in this study. Results confirmed that optimizing fertilizer N application rates under SRI is important to increase yield, N use efficiency and water use efficiency.


Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 170
Author(s):  
Chusnul Arif ◽  
Satyanto Krido Saptomo ◽  
Budi Indra Setiawan ◽  
Muh Taufik ◽  
Willy Bayuardi Suwarno ◽  
...  

Evapotranspirative irrigation is a simple idea in a watering field based on the actual evapotranspiration rate, by operating an automatic floating valve in the inlet without electric power to manage water levels. The current study introduces a model of evapotranspirative irrigation and its application under different water levels. The objectives were (1) to evaluate the performances of evapotranspirative irrigation under various irrigation regimes, and to (2) to observe crop and water productivities of the system of rice intensification (SRI) as affected by different types of irrigation. The experiment was performed during one rice planting season, starting from July to November 2020, with three irrigation regimes, i.e., continuous flooded (CFI), moderate flooded (MFI) and water-saving irrigation (WSI). Good performance of the system was achieved; low root mean square error (RMSE) was indicated between observed water level and the set point in all irrigation regimes. Developing a better drainage system can improve the system. Among the regimes, the WSI regime was most effective in water use. It was able to increase water productivity by up to 14.5% while maintaining the crop yield. In addition, it has the highest water-use efficiency index. The index was 34% and 52% higher than those of the MFI and CFI regimes, respectively. Accordingly, the evapotranspirative irrigation was effective in controlling various water levels, and we recommend the system implemented at the field levels.


2017 ◽  
Vol 9 (1) ◽  
pp. 286-290
Author(s):  
M. Paramasivan ◽  
A. Selvarani

Four hundred and sixteen on-farm demonstrations on system of rice intensification (SRI) were carried out in 350 hectares of farmer’s fields in Sankarankovil, Vasudevanallur and Kuruvikulam blocks of Tirunelveli district of Tamil Nadu from 2008-09 to 2010-11 under Tamil Nadu – Irrigated Agriculture Modernization and Water Bodies Restoration and Management (TN-IAMWARM) project. Two methods viz., SRI and conventional were compared. The results revealed that the adoption of SRI favorable influenced yield attributes and yield of rice. The maximum grain yield (8222 kg ha-1) obtained from SRI which was higher than conventional method (6534 kg ha-1). Higher grain yield coupled with substantial water saving to the tune of 37.1 per cent resulted in higher water use efficiency of rice under SRI method. The best net income ( Rs. 50, 587) and benefit: cost ratio (3.64) were also associated with SRI than conventional method of rice cultivation. The cost of cultivation was comparatively lesser in SRI which re-sulted in gaining an additional income of Rs. 8080 ha-1 as compared to conventional method of rice cultivation. The system of rice intensification (SRI) proved its benefits in this basin.


2019 ◽  
Vol 6 (12) ◽  
pp. 223-231
Author(s):  
Hiba Ghazouani ◽  
Basma Latrech ◽  
Boutheina M. Douh ◽  
Cherni Amani ◽  
Mguidich Belhaj Amel ◽  
...  

In Tunisia, water scarcity forces producers to face stress conditions. In this study, AquaCrop was used to reproduce the dynamic of water contents, vegetative growth, yield production and water use efficiency under a non-stressed and water stressed treatments. Calibration procedure aimed to use in maximum default parameters of AquaCrop. Since, the paper presented only the parameters that have to be adjusted to obtain similar results of field measurements. Root mean squared error, RMSE, values were always lower than 0.04 cm3.cm-3 for water contents lower than 0.06 for vegetation cover estimation. Moreover, results from Nasch Coefficient, E, were almost equal to one. RMSE and E justified that the model was well assessed to predict the soil water contents and vegetation development under the study area. However, the model presented a greater performance in the case of full irrigation strategy. When evaluating different values of water productivity, it was showed that a WP of 32 g.m-2 produced the lowest estimation error. Regarding yield productions, statistical indictors, computed for a water productivity value of 32 g.m-2 show in general RMSE values lower than 0.4 t/ha. In addition, E was closer to one for the non stressed treatment, T1. For irrigation water use efficiency, it was depicted that the model underestimated field IWUE. Moreover, the discrepancy between simulated and estimated irrigation water use efficiency rose for treatment T2, implying that the model calibration should be improved, especially for stressed conditions. The model, after being calibrated, could be used for simulating the response of the crop to different irrigation management aiming to optimize water use efficiency.


2019 ◽  
Vol 124 (4) ◽  
pp. 581-589 ◽  
Author(s):  
Michael Papacek ◽  
Alexander Christmann ◽  
Erwin Grill

Abstract Background and Aims Water deficit is the single most important factor limiting plant productivity in the field. Poplar is a crop used for second-generation bioenergy production that can be cultivated on marginal land without competing for land use in food production. Poplar has a high demand for water, which makes improving its water use efficiency (WUE) an attractive goal. Recently, we showed that enhanced expression of specific receptors of arabidopsis for the phytohormone abscisic acid (ABA) can improve WUE in arabidopsis and water productivity, i.e. more biomass is formed per unit of water over time. In this study, we examined whether ABA receptors from poplar can enhance WUE and water productivity in arabidopsis. Methods ABA receptors from poplar were stably introduced into arabidopsis for analysis of their effect on water use efficiency. Physiological analysis included growth assessment and gas exchange measurements. Key Results The data presented here are in agreement with the functionality of poplar ABA receptors in arabidopsis, which led to ABA-hypersensitive seed germination and root growth. In addition, arabidopsis lines expressing poplar RCAR10, but not RCAR9, showed increased WUE by up to 26 % compared with the wild type with few trade-offs in growth that also resulted in higher water productivity during drought. The improved WUE was mediated by reduced stomatal conductance, a steeper CO2 gradient at the leaf boundary and sustained photosynthesis resulting in an increased intrinsic WUE (iWUE). Conclusions The analysis is a case study supporting the use of poplar ABA receptors for improving WUE and showing the feasibility of using a heterologous expression strategy for generating plants with improved water productivity.


Rice ◽  
2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Prathibha M. Dharmappa ◽  
Pushpa Doddaraju ◽  
Mohankumar V. Malagondanahalli ◽  
Raju B. Rangappa ◽  
N. M. Mallikarjuna ◽  
...  

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