A field study was conducted at Al-Mishkhab Rice Research Station (MRRS) during the summer season 2009 to evaluate irrigation water use efficiency (IWUE) using Anbar 33 variety with the System of Rice Intensification compared to traditional methods. During the growth phase, the number of leaves, stems, and roots, and the average plant height were measured every 15 days for the two sets of methods. At maturity, the depth and length of plant roots was assessed, along with leaf area index (LAI) of the flag leaf and plant height. The amount of irrigation water applied was measured by water meter for both methods. SRI principles for plant age, spacing, etc., were implemented in the SRI plots. The results indicated more vigorous growth of roots under SRI methods, reaching 13,004 cm plant -1 compared with non-SRI results of 4,722 cm plant -1 . There was 42% increase in grain yield when SRI methods were used. These had water use efficiency (WUE) of 0.291 kg m -2 compared with WUE of 0.108 kg m -2 for non-SRI cultivation, almost a threefold difference. SRI practices reduced the need for irrigation water by 38.5%.

The conservation of natural resources like soil and water and reduces chemical pollution in the environment is the desired goal of the directions of improving the performance of important crops that to meet the global food demand. However System of Rice Intensification (SRI), is a rice cropping system that is consistent with Conservation Agricultural (CA) and Sustainable Agriculture (SA). The current study was aimed to investigate the effects of SRI method on grain yield and its components in two rice varieties compared with conventional practice in farmers' fields (CFM) in different environmental conditions in Iraq. Study was conducted in the fields during the rice season 2019 in three provinces in south of Iraq (Najaf, Diwaniya and Muthanna ). Anber33 and Jasmine rice varieties were grown in each location and the traits were conducted at sites having two donum of land (5,000 m2). The trial was performed as factorial expriments based on a randomized complete blocks design (RCBD) having three blocks. The results showed superior significant of SRI method compared to CFM method in traits (plant height and panicle length, number per panicle and percentage of unfilled grains). Furthermore, SRI method gave higher grain yield as percentage with both varieties in each province (25.6% in at Muthanna, 24.5% in Najaf and 13.2% in Diwaniya province) compared to CFM. However, grain yield in Jasmine variety was higher than on Anber33 approximately 50% in three locations in this study. Overall, our results suggest that SRI method is the most convenient method in Iraq conditions due to the increased grain yield in rice compared to the CFM method.

The conservation of natural resources like soil and water and reduces chemical pollution in the environment is the desired goal of the directions of improving the performance of important crops for meeting the global food demand. However,System of Rice Intensification (SRI), is a rice cropping system that is consistent with Conservation Agricultural (CA) and Sustainable Agriculture (SA). The current study was aimed to investigate the effects of SRI method on grain yield and its components in two rice varieties compared with conventional practice in farmers' fields (CFM) in different environmental conditions in Iraq. The study was conducted in the fields during the rice season 2019 in three provinces in the south of Iraq (Najaf, Diwaniya and Muthanna). Anber33 and Jasmine rice varieties were grown in each location and the traits were conducted at sites having 2 donum of land (5,000 m2).The trial was performed as a factorial experiment based on a randomized complete blocks design (RCBD) having three blocks. The results showed superior significant of SRI method compared to CFM method in traits (plant height and panicle length, number per panicle, and percentage of unfilled grains). Furthermore, SRI method gave higher grain yield as a percentage with both varieties in each province (25.6% in Muthanna, 24.5% in Najaf, and 13.2% in Diwaniya province) compared to CFM. However, grain yield in Jasmine variety was higher than on Anber33 approximately 50% in three locations in this study. Overall, our results suggest that SRI method is the most convenient method in Iraq conditions due to the increased grain yield in rice compared to the CFM method.

This study evaluated what intervals of irrigation in conjunction with the use of SRI methods could achieve the greatest economic, as well as agronomic returns when growing irrigated rice under the water-deficit conditions of southern Iraq. A field study at the Al-Mishkhab Rice Research Station in southern Iraq recorded input and output data for three different irrigation regimes: continuous submergence of the rice crop; irrigation at 3-day intervals; and irrigation at 7-day intervals. Benefit–cost analysis showed 3-day intervals with SRI methods, giving the highest net returns and highest internal rate of return, indicating that the continuous irrigation of rice fields is a waste of water, with neither agronomic nor economic benefit. In Iraq, there are large opportunity costs for any unnecessary use of irrigation water. The highest water productivity was achieved with 7-day intervals of irrigation together with SRI methods, but this entails some sacrifice of the yield ha−1, as 13% less grain is produced than with continuous submergence of the crop. With 7-day intervals compared to 3-day intervals, water-saving was 44%, but compared to continuous submergence of the crop, the saving was 72%. This large amount of water could, if redeployed, enable many more farmers to cultivate larger areas of the land, increasing total rice production for Iraq, and some of the water saved could be put to other, high-value uses. It would thus benefit the country and many farmers if, in return for rice farmers’ using irrigation water more productively, those who currently grow rice could be persuaded to accept a grain yield somewhat lower than they could produce with 3-day intervals of irrigation and SRI crop management. The redeployment of water saved by having longer irrigation intervals coupled with SRI methods could raise Iraq’s rice output more than enough to compensate the farmers for forgoing some attainable production by their accepting 7-day irrigation intervals. If no such incentive scheme could be established, there would still be a significant benefit for farmers and for the country by moving to SRI production methods with 3-day intervals rather than continuing the present practice of routinely flooding rice fields and using conventional methods.

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