Irrigation and Drainage最新文献

This study aimed to determine the impact of supplemental irrigation (SI) on the water use efficiency and yield of haricot beans during the growing seasons from 2020 to 2022. Six treatments were tested, including rain-fed/no irrigation (T1), full irrigation throughout the season (T2), SI at vegetative, flowering and pod formation (T3), SI at emergence, vegetative and pod formation (T4), SI at emergence, flowering and grain filling (T5) and SI at emergence, pod formation and grain filling (T6), with three replications arranged in a randomized complete block design. The results showed that T2 significantly affected all growth and yield parameters except pod length and harvest index. However, T3 provided better water use efficiency and more acceptable yield reduction than T2. Thus, applying SI during the vegetative, flowering and pod formation phases proves to be more efficient for the production of haricot beans in the area under study as it leads to better economic returns and water productivity. In summary, irrigating the crop during the critical growth stages would result in water conservation and improved water productivity. Further research is recommended on SI to improve water use efficiency across different locations and seasons.

Cette étude visait à déterminer l'impact de l'irrigation d'appoint (IS) sur l'efficacité de l'utilisation de l'eau et le rendement des haricots pendant les saisons de croissance de 2020 à 2022. Six traitements ont été testés, y compris en culture pluviale/sans irrigation (T1), l'irrigation complète tout au long de la saison (T2), la SI au stade végétatif, à la floraison et à la formation des cosses (T3), la SI à l'éclosion, au stade végétatif et à la formation des gousses (T4), la SI à l'éclosion, à la floraison et au remplissage des grains (T5) et la SI à l'éclosion, à la formation des cosses et au remplissage des grains (T6), avec trois répétitions disposées en blocs complets aléatoires. Les résultats ont montré que T2 a eu une incidence significative sur tous les paramètres de croissance et de rendement, à l'exception de la longueur des cosses et de l'indice de récolte. Cependant, le T3 a permis une meilleure efficacité de l'utilisation de l'eau et une réduction acceptable du rendement que le T2. Ainsi, l'application de la SI pendant les stades de végétation, de floraison et de formation des cosses s'avère plus efficace pour la production de haricots dans la zone étudiée, car elle conduit à de meilleurs rendements économiques et à une meilleure productivité de l'eau. En résumé, l'irrigation de la culture pendant les stades critiques de la croissance se traduirait par la conservation de l'eau et une meilleure productivité de l'eau. Il est recommandé de poursuivre les recherches plus approfondies sur l'irrigation d'appoint afin d'améliorer l'efficacité de l'utilisation de l'eau à différents lieux et saisons.

Subsurface pipe drainage (SPD) could provide a suitable environment for crop production in arid and semi-arid agricultural areas; however, less attention has been given to the design layout of SPD on the regional scale in Hetao Irrigation District (HID). In this study, the appropriate layout of the final subsurface pipe was determined using the distributed SWAP-WOFOST (Soil–Water–Atmosphere–Plant and WOrld FOod STudies) model in HID. Subsequently, the impact of the proper SPD on crop yield and water productivity (WP) were evaluated. Finally, the crop zoning was adjusted to further enhance crop WP, and the corresponding newly added cultivated land area was preliminarily estimated based on the suggested SPD. The results indicated that after zoning in the suggested SPD, the annual average yields of spring wheat, spring corn and sunflower increased by 19%, 7% and 11%, respectively, and WP improved by 13%, 5% and 10%, respectively, compared to the traditional layout. The newly added cultivated land area was estimated to be approximately 3489 ha through the replacement of traditional end ditches with subsurface pipes in HID. Therefore, the suggested subsurface pipe designs and cropping pattern adjustment improved crop growth and led to an increase in the cultivated land area in HID.

Most of the agency-built surface irrigation systems in Nepal the operation and maintenance (O&M) of which are being managed by irrigation agencies jointly with farmers are not performing satisfactorily. The unreliable delivery of irrigation services to farmers is one of the reasons for this. Thus, the most important challenge in the past and in the present is how to enhance the delivery of irrigation services to farmers.

If one examines the private sector management of other public enterprises, they are efficiently delivering services to their clients. Considering this aspect, the government of Nepal recognized that irrigation systems or parts of them may also be managed through private irrigation operators (PIOs) under a fixed-term management contract to enhance their service delivery.

This paper analyses the O&M of jointly managed irrigation systems (JMISs) and suggests that a lack of capacity, accountability and incentive mechanisms on the part of irrigation agencies are the principal causes pertaining to the deficient delivery of irrigation services in them. It further suggests that introducing PIOs in managing the operation and maintenance of part of the JMISs can address these causes. The paper argues that the said PIO approach is viable from financial, technical and managerial perspectives.

In many arid and semi-arid regions, such as Iran, traditional irrigation systems consume a large proportion of surface water and groundwater resources. In the last few decades, due to the undesirable effects of climate change and continuous drought, many studies have been conducted on reducing threatening factors using the capacity of irrigation and drainage networks and participating water users in irrigation management. This study aimed to evaluate the performance of the irrigation and drainage network of the Varamin Plain using the SWOT model that is an analytical model used based on the results of the strengths, weaknesses, opportunities and threats of the subject, considering the cooperative management of water users. In addition to conducting interviews, a questionnaire was used to collect data from two groups of network water users and experts. According to the results, the farmers and water users of the network are in a relatively good situation in terms of access to water, possibly due to the available three annual planting seasons (due to the existence of irrigation and the drainage network and the use of grey water, conditions for irrigation and crop cultivation are available in four seasons of the year). The most critical concerns of the water users were the lack of knowledge about the organization of water collectors, the inconsistency among governmental organizations and the insignificant action of the Agricultural Jihad Organization (a government ministry in Iran to advance agricultural goals and all related matters) in solving issues related to water rights. Failure to inform the users about the costs of creating network infrastructure, maintaining facilities and canals, not accepting water shortage conditions and the state of groundwater resources, consecutive cropping seasons throughout the year, cultivation of crops with high water demand, people with political and social influence obtaining excess water rights, and the lack of coordination among related governmental policies were the most critical concerns of the experts.

Subsurface drainage is effective for not only controlling groundwater levels in agricultural lands but also alleviating soil salinity localized at the root zone, especially for arid and semi-arid agro-ecosystems. In this research, an optimization model that minimizes the overall costs of subsurface drainage systems subjected to design constraints was formulated. The Lagrange multiplier method for optimization was utilized to derive a general differential equation for obtaining the most economical design of the subsurface drainage system. Design charts for the minimum cost of the subsurface drainage network ($ ha⁻¹) for lateral diameters (dL) of 2.5, 5, 7.5, 10 and 12.5 cm; hydraulic conductivities (K) of 0.5, 1, 2, 3 and 4 m day⁻¹; different lateral lengths (L_L) of 100, 150, 200, 250, and 300 m; a constant collector length (L_C) of 1000 m (assuming laterals join the collector from both sides); drainage recharge (q) values of 1, 2, 3, 4 and 5 mm day⁻¹; and excavation depths of 1.5 and 2.0 m were developed. The minimum computed subsurface drainage network (SSDN) costs observed at a lateral length (L_L) of 300 m were 205, 246, 288, 331 and 374 ($ ha⁻¹) for lateral diameters of 2.5, 5, 7.5, 10 and 12.5 cm, respectively, corresponding to lateral spacing of 175, 176, 177, 178 and 179 m. The suggested charts for the optimum design of a subsurface drainage system have lower overall costs than using conventional design approaches for pipelines and tube wells. The results will support solutions for designers to implement subsurface drainage systems with less and more affordable expenses in the old lands of the Nile delta of Egypt and other regions with similar agrosystems. Quality control during construction is very necessary for guaranteeing the effective and sustainable performance of subsurface drainage systems for many years.

To improve the fertilizer injection performance of a non-axisymmetric Venturi injector (NAVI), the effects of the contraction angle, diffusion angle, throat diameter and tilt angle of the injection pipe on the fertilizer injection performance of NAVI were examined. Based on the test, the original NAVI was optimized, and the fertilizer injection performance of NAVI before (F1) and after (F2) optimization was compared. Then, a non-axisymmetric Venturi injector with arc diffusion (F3) was proposed. The results showed that when the water inlet diameter of the non-axisymmetric Venturi injector was 25 mm, the optimal structural parameters were as follows: the contraction angle was 40°, the diffusion angle 6°, the throat diameter 7 mm and the tilt angle of the injection pipe was 120°. Compared with F1, the injection rate and fertilizer injection efficiency of F2 increased by 21–66 and 27–79%, respectively. Changing the diffusion section of NAVI into an arc structure was conducive to reducing the vortex area size by 11% and improving the injection rate by 20–62%. The results can provide an important reference for the structural design of Venturi injectors.

To investigate the effects of various biochar application levels on the growth physiology and water use efficiency of dry direct-seeded rice (DDSR) in the black soil region of north-east China, five biochar application treatments consisting of 2% (BC1), 4% (BC2), 6% (BC3), 8% (BC4) and 10% (BC5) were set, and no biochar application was used as the control treatment (CK). The differences in photosynthetic properties, dry matter accumulation characteristics, water consumption pattern, yield and water use efficiency of DDSR under different biochar application levels were compared and analysed, and the effect of the water use efficiency of leaves (WUE_L) at each growth stage on the water use efficiency of yield (WUEy) was also investigated. The results showed that the photosynthetic properties, dry matter accumulation and water consumption of rice increased and then decreased with increasing biochar application level. Compared with CK, the rice yield increased by 1.6%–52% with biochar application, and the 4% biochar application level showed the most significant increase in rice yield (P < 0.05). The WUEy in the BC2, BC3, BC4, BC1, CK and BC5 treatments gradually decreased in that order. Among the WUEy values, significant increases of 27%, 13% and 8% in the BC2, BC3 and BC4 treatments, respectively, compared with the CK were observed (P < 0.05). The effect of WUE_L at the prophase tiller, late tiller and milk ripening stages on WUEy enhancement was significant.

The sustainable use of soil and water resources is a goal that should be pursued to attain food security. This investigation was implemented to compare the effects of three legume intercropping systems with sugar beet on (i) enhancing sugar beet yield under imposed water stress conditions, (ii) soil N contents, (iii) land and water use efficiencies, and (iv) farmers' net income. Two field experiments were carried out in the 2018/19 and 2019/20 seasons in the El-Minia Governorate, Egypt. The treatments included the interaction between three irrigation treatments: required irrigation ((control, 100% ETc, RI) and two levels of imposed water stress (85% ETc (WS₁) and 70% ETc (WS₂)), and three intercropping systems: faba bean (FIS), chickpea (CIS) and lentil (LIS) intercropped with sugar beet. The results indicate that the application of implementing CIS and with RI attained higher average values of soil N content (SNC = 14.0 mg kg⁻¹) and net income (NI = US$3,974 ha⁻¹) than those obtained by sugar beet alone. Irrigation with WS₁ and the implementation of CIS gave a value of SNC (12.3 mg kg⁻¹) close to that obtained under sugar beet alone irrigated with RI. CIS irrigated with WS₁ attained higher averaged values of land equivalent ratio (LER = 1.34), area time equivalent ratio (ATER = 1.28), land equivalent coefficient (LEC = 0.38), water equivalent ratio (WER = 1.12), negative value of change in water use (ΔWU < 0) and NI (US$3,602 ha⁻¹) than those obtained under FIS or LIS irrigated with RI. In conclusion, implementing CIS and irrigation with RI can achieve the sustainable use of land and water. However, implementing CIS and irrigation with WS₁ can realize soil improvement, conserve irrigation water and attain higher values of LER, ATER, LEC, WER, and NI than those obtained under FIS, LIS and sugar beet alone.

To promote sustainable production and the multiple roles of paddy rice, it is essential to expand our understanding of the impacts of different management options, with particular emphasis on irrigation development. The impact of various management practices (supplementary irrigation during the rainy season, improved fertilization, cropping during the dry season and mulching practices) on irrigation water requirements, crop productivity and the multifunctional roles of irrigated paddy rice was evaluated in diverse agro-ecological zones of Zambia, by using the AquaCrop model. Irrigation development has been demonstrated to boost paddy rice production (by 8%) in the southern districts by providing supplementary irrigation (about 150 mm) during the rainy season. Additionally, supplementary irrigation during the rainy season can make improved fertilization more attractive, doubling the yield rise under rainfed conditions. The required irrigation development would also enable paddy rice cropping intensification by allowing for dry season sowing (with net irrigation requirements from 700 to 800 mm). Moreover, the associated straw production increase could also play an important role as mulch during the dry season, reducing the net irrigation requirements by 15%. These findings will enable policymakers to make informed decisions regarding investment strategies and policies.

Maize (Zea mays L.) is the third most important cereal crop produced globally after wheat and rice and provides the basic raw materials for starch, oil, protein, alcoholic beverages, food sweeteners and fuel. It is grown on an area of 201.98 Mha worldwide, with an average productivity of 5.75 t ha⁻¹. Maize is mostly grown during the rainy season, but it performs better during the winter season with irrigation and resource conservation techniques. The average productivity of maize during the rainy and winter seasons is 4.3 and 6.2 t ha⁻¹, respectively. The total production is as low as 2.7 Mt in Nepal to 362.78 Mt in the USA. Maize performs better under the furrow and drip irrigation methods, and the range of water requirements is between 425–789 and 351–685 mm, respectively. Plastic and straw mulching has enhanced irrigation water use efficiency up to 34.0–47.2 and 15.3–24.1 kg ha⁻¹ mm⁻¹, respectively. The crop coefficients, K_c values, for maize crops ranges between 0.2 and 1.2. Of the different methods of irrigation, the drip irrigation method enhances the maize yield by 28% and plays a great role in corn yield. This paper discusses various strategies for enhancing global maize yield.