Moderate Irrigation Research Articles

Study of ancestral irrigation systems in the oasis of Taghit in the South West of Algeria

The unique oasis of Zousfana, on the western edge of the Grand Erg Occidental, Taghit is the pearl of the oases of Saoura, a palm grove of 180 ha over an 18 km length crossed by Oued Zouzfana. It regroups the different types of landscapes of an arid zone (erg, hamada, barga – a small hill, oued ...). Taghit is known for its hydraulic civilization, the oasis in its hostile environment has survived thanks to the exploitation of rare groundwater irrigation according to the traditional customs applied to the whole of society. The peasants spur out the water resources through foggaras and traditional wells. But the intervention of modern irrigation techniques in an anarchic way has disrupted the fragile mode of irrigation and the abandonment of the palm grove. The over-exploitation of groundwater by the use of boreholes and motor pumps leads to the drying up of water sources, mists and traditional wells. Today, only 45 000 palm trees are productive and less than 1500 fruit trees. There are 500 fellahs in the entire agricultural area of Taghit, the majority of them is fleeing work in the oasis because of the lack of income from it. When comparing the results of analyses from different campaigns (2015 and 2008), a spectacular increase in the salt concentrations in the groundwater of the different palm groves is noticed. According to our investigations, the main causes of this jump are: the overexploitation of the water tables by motor pumps, the abandonment of land inside the palm grove, the lack of maintenance of the gardens, the exploitation of domestic wastewater in the irrigation. According to this preliminary study, it is important for the State to make farmers aware of the role of their traditional irrigation systems in the continuity of the oasis and life in it.

The effectiveness of resource-saving techniques for the cultivation of onions during irrigation in the conditions of the Lower Volga

Relevance. The main areas under vegetables, including onions, are located in the south of Russia. Inclusion of vegetables in the list of food safety products with a threshold value of 90% will significantly increase the responsibility of agricultural workers at all levels for the production and sale of vegetable products. The purpose of the research is to justify the feasibility and effectiveness of cultivating promising varieties and hybrids of onions during irrigation in the Lower Volga region to obtain yields of 150 or more t/ha of high-quality products.Methods. For the first time in the area of chestnut soils, comprehensive scientific research was conducted on resource-saving techniques to increase the productivity of a vegetable crop in an extremely arid climate by regulating the physiological and biological processes during drip irrigation, and a system was developed for applying these techniques. Research in the experiment was carried out according to generally accepted methods.Results. The most significant increase in the onion crop was obtained on the variants of the complex application of the studied agricultural methods and amounted, on average, for 2011...2016 with an irrigation regime of 75...75...75% of HB on the standard variety Volgodonets – 159%, relative to the control, on a promising hybrid Octant F1 – 118%, on the hybrid – 125%. With the regime of 70...80...75% of HB on the Volgodonets standard grade – 155%, relative to control, on the promising Oktant F1 hybrid 113%, on the Valero F1 hybrid – 115%. When calculating the cultivation efficiency of this crop, economic data were obtained, the value of which allows us to conclude that when planning the growth of onion production efficiency, agricultural producers are recommended to introduce agricultural technology with a profitability of 253.63%: promising hybrid Octant F1, irrigation mode – differentiated, background N450P180K135+Mortar+Energy-M. Against this background, in the context of research on the variety and hybrids, the maximum return on production costs is 3.2 rubles. An analysis of data on a combination of crop-forming factors showed that for onions when cultivating promising hybrids Octant F1 and Valero F1, when planning yields of 130 and 150 t/ha, it is necessary to maintain a moisture level of 70...80...75% HB, and when grown without fertilizers and when planning 110 t/ha it is enough to create a permanent irrigation regime.

Methane Emission Related to Enzyme Activities and Organic Carbon Fractions in Paddy Soil of South China Under Different Irrigation and Nitrogen Management

The objectives of this study were to obtain rational irrigation and nitrogen (N) management for reducing methane (CH4) emission from paddy field and understand how CH4 emission flux is affected by the changes in soil enzyme activities and organic carbon fractions under different irrigation and N management. Two-season field experiments were conducted with three irrigation modes, conventional irrigation (C), “thin-shallow-wet-dry” irrigation (T), and alternate drying and wetting irrigation (D), and two N treatments, 100% urea (FM1) and 50% urea and 50% pig manure (FM2), to investigate CH4 emission flux, soil enzyme activities, and organic carbon fractions and analyze the relationships between them. CH4 emission fluxes from early and late rice fields peaked at tillering stage (652.74 and 103.78 mg m−2 h−1). Compared to C mode, D and T modes increased early rice yield and D mode also increased total yield of both seasons. However, D and T modes decreased cumulative CH4 emissions over the whole growth period under FM2. CH4 emission flux was positively correlated with saccharase activity and microbial biomass carbon (MBC), but negatively correlated with cellulase activity. Path analysis indicates that cellulase activity had a direct negative effect on CH4 emission. FM2-D and FM2-T were rational irrigation and fertilizer treatments for rice production with higher yield and lower CH4 emission, and CH4 emission flux was affected by the changes in MBC, saccharase, and cellulase activities in soils under different irrigation and N management.

Relationship of population quality and nitrogen fertilizer utilization characteristics of direct seeding rice under water-nitrogen interaction

Understanding population quality and nitrogen utilization characteristics of direct seeding rice under water-nitrogen interaction could provide theoretical and practical basis for high yield and ample production of direct seeding rice. Hybrid rice F You 498 was used as the material. Three irrigation methods were set in this study: flooding irrigation (W1), dry-wet alternate irrigation (W2) and drying irrigation (W3), with different ratio of base fertilizer: tiller fertilizer: panicle fertilizer at 5:3:2 (N1), 3:3:4 (N2), 3:1:6 (N3), respectively. No nitrogen application (N0) was set as the control. We investigated the effects of water-nitrogen interaction on population quality and nitrogen utilization characteristics of direct seeding rice, with the aim to clarify the relationship between population quality construction, nitrogen utilization characteristics and yield of direct seeding rice. The results showed that irrigation and N rate significantly interacted to affect dry matter accumulation, rice harvest index, heading high-efficiency leaf (the upper three leaves) dry weight, light transmittance rate at maturity stage, total nitrogen accumulation (TNA), apparent nitrogen use efficiency (ANE), nitrogen partial factor productivity (NPFP), nitrogen physiology efficiency, and rice yield. Taking population quality, yield and N fertilizer utilization characteristics into consideration, suitable panicle N-fertilizer under each irrigation mode was 20%-40% (N1-N2). Panicle N-fertilizer reached 60% (N3) and W3 treatment would significantly reduce population quality, yield, nitrogen agronomy efficiency (NAE), NPFP of direct seeding rice. Yield and nitrogen utilization characteristics of direct seeding rice were significantly correlated with effective panicles, dry matter accumulation at maturity stage, other leaf (except the upper three leaves) dry weight reduction, total leaf dry weight reduction, and middle part and basel part light-receiving rate under water-nitrogen interaction. The dry-wet alternative (W2) treatment could increase the rate of production til-lers, dry matter accumulation, rice harvest index, TNA, NAE and rice yield. W2 combined with N2 could improve population quality of direct seeding rice and realized the coordination and unification of high yield and efficient utilization of nitrogen, which is the best combination in this experiment.

Impact of Irrigation on India’s Dairy Economy

This paper explores the impact of irrigation on India’s mixed crop-based dairy production system. It uses a four-equation recursive regression model to outline the impact of water applied under different modes (groundwater irrigation, surface water irrigation, and rainfall) on the bovine herd efficiency and dairy output. The results of the model show that rain-fed areas account for 47% of the total value of milk output, whereas area under groundwater irrigation and surface water irrigation account for 38% and 15%, respectively. Of all the different irrigation modes, groundwater irrigated areas have the most efficient bovine herd for milk production. The addition of one hectare of groundwater in an irrigated area adds around Indian Rupees (INR) 20,000 (~US $448) to the gross value of milk output of a district, which is twice the addition of one hectare of surface water in an irrigated area and five times the addition of one hectare of rainfed area. Based on the results of the model, the paper suggests that expanding well irrigation in the groundwater-abundant eastern and central tribal belt of India can yield a positive impact on milk production.

Productivity and adaptive abilities of corn hybrids under different irrigation modes and moisture supply in the Arid Steppe of Ukraine

Productivity and adaptive abilities of corn hybrids under different irrigation modes and moisture supply in the Arid Steppe of Ukraine

Utilization of grafting technique for sustaining cantaloupe productivity and quality under deficit irrigation water

BackgroundWater use efficiency (WUE) is becoming a decisive factor for agricultural expansion to face water shortage. To meet the needs of high population density in Egypt, we have to use modern irrigation systems and new cultivation technologies. The current study is aiming to apply grafting technique for ameliorating the impact of deficit water on cantaloupe productivity and fruit quality. Two commercial cultivars (Ideal and Veleta) were grafted on two rootstocks (Cobalt and Strong-Tosa) and self-grafting. The seedlings were treated with three different irrigation levels: 100, 75, and 50% of Class A pan Evapotranspiration (ETc).ResultsThe results showed that moderate irrigation level (75% ETc) increased the early yield, fruits number, by 15.3 and 17.4%, respectively, compared to control irrigation treatment (100% ETc). No significant variation was found concerning total yield between 100 and 75% ETc, so this led to an increase in WUE of moderate irrigation level (75% ETc) by 34.3%, compared to control irrigation treatment (100% ETc). Increasing deficit levels up to 50% ETc reduced the total yield by 47.4%, but it increased the WUE by 8.8%, compared to the non-deficit irrigation level (100% ETc). Meanwhile, grafting both cultivars on Cobalt rootstock improved the fruit number, total yield, and WUE by 39.2%, 26.9%, and 24.1%, respectively when irrigated with the moderate irrigation level (75% ETc), as compared to the non-grafted plants which recorded the highest decrease when irrigated with deficit irrigation level (50% ETc).ConclusionFinally, the combination treatments of Ideal/Strong-Tosa, Veleta/Cobalt, or Ideal/Cobalt irrigated with moderate irrigation level (75% ETc) increased the WUE by 97.3, 83.4, and 65%, respectively, compared to the control treatment (non-grafted plants of the same cv. at 100% ETc) and recorded higher flesh thickness, TSS and firmness.

Clinical, host-derived immune biomarkers and microbiological outcomes with adjunctive photochemotherapy compared with local antimicrobial therapy in the treatment of peri-implantitis in cigarette smokers.

The aim of this study was designed to assess the peri-implant oral hygiene parameters, clinical, radiographic, host-derived immune biomarkers and microbiological levels after photochemotherapy (PCT) and local antibiotic therapy (LAT) in peri-implantitis lesions among cigarette smokers. Fifty current cigarette smokers with peri-implantitis were divided into two groups: PCT and LAT. Test implants received PCT that consisted of toluidine blue photosensitizer and application of 660 nm diode laser with a total of 100 mW power and 124.3 W/cm2 energy using continuous mode of irrigation for 60 s. Control implants received one-unit subgingival application of metronidazole gel in viscous consistency. Clinical measurements included the assessment of plaque scores (PS), bleeding on probing (BOP), probing depth (PD) and clinical attachment level (CAL). Intraoral standardized digital peri-apical radiographs were taken at baseline and at 12 months. Interleukin (IL)-1β and matrix metalloproteinase (MMP)-1 in the PICF were determined using the manufacturers guide from one-step enzyme-linked immunosorbent assay. Real-time polymerase chain reaction (PCR) for Parvimonas micra, Porphyromonas gingivalis and Tannerella forsythia was performed and counts evaluated at baseline, 3, 6 and 12-months. Plaque scores reduced in both groups (p < 0.05). Mean BOP percentage significantly increased in both the groups at 1-month follow-up compared to baseline. Following this period, BOP showed reduction from 1-month to consecutive follow-up periods. The PD significantly reduced in both the groups with no statistically significant difference when compared between PCT and LAT groups at follow-up (p > 0.05). CAL did not change over the period and between both groups (p > 0.05). The differences from baseline to 12 months and between the groups for mesial and distal crestal bone levels did not show any statistical significance (p > 0.05). The levels of IL-1β significantly dropped from baseline to 12 months in the LAT group (p < 0.05). However, for PCT groups, the levels of IL-1β significantly reduced only at 12-month visit follow-up (p < 0.05). MMP-1 showed statistically significant reduction at 9 and 12-months compared with baseline for LAT group. Both P. gingivalis and T. forsythia showed statistically significant reduction in both the groups when values were compared from baseline to 3-, 6- and 12-months follow-up (p < 0.05). However, these differences were not significant when compared between the groups (p > 0.05). Both PCT and LAT showed equal efficacies in improving clinical, host-derived immune biomarkers and microbiological parameters in peri-implant infection in cigarette smokers.

Pure phaco: phacoemulsification without ophthalmic viscosurgical devices

The ophthalmic viscosurgical device (OVD) is an essential part of modern phacoemulsification surgery. Many times, OVDs are blamed for intraocular pressure spikes, toxic anterior segment syndrome, and capsular bag distension syndrome. To avoid these complications, we developed a technique in which phacoemulsification can be done without using OVDs. The irrigating cannula, on a continuous irrigation mode, was introduced through a side port, and capsulorhexis and incision construction were performed under an irrigating balanced salt solution. No hydroprocedure was performed. Phacoemulsification was done by chopping technique. At the end of the procedure, the intraocular lens was implanted by wound assistance technique under a continuous irrigation mode.

Direct root-zone irrigation outperforms surface drip irrigation for grape yield and crop water use efficiency while restricting root growth

Direct root-zone irrigation is a novel subsurface drip irrigation strategy for water conservation. However, a comparison with traditional irrigation methods is lacking to better define the potential advantages of direct root-zone irrigation. A two-year study was conducted to evaluate the performance of Vitis vinifera L. cv. Cabernet Sauvignon under direct root-zone irrigation and surface drip irrigation in a commercial vineyard with loamy sand soil in a semi-arid region of southcentral Washington State, USA. Plant water status, root traits, grape yield, berry morphology and composition, and crop water use efficiency were compared between irrigation methods under three irrigation rates. Compared to surface drip irrigation, direct root-zone irrigation improved grape yield by 9–12% and crop water use efficiency by 9–11% under varied climate conditions with minor effects on berry composition, which could be potentially adjusted by irrigation rate. Moreover, grapevines irrigated through direct root-zone irrigation had 48–67% and 50–54% decrease in root number, respectively, at high and moderate irrigation rates in the upper soil profile (0–60 cm) with a decrease in water stress as revealed by higher midday stem water potential. Irrigation rate was the major factor influencing berry morphology. In fact, reduced irrigation resulted in a decrease in weight, size and number of berries. We conclude that direct root-zone irrigation could be a successful tool for improving yield and crop water use efficiency, potentially encouraging deep rooting to alleviate the water stress in grapevine under seasonal drought, and offering the ability to modify berry morphology and composition by adjusting the amount of water use.

ОСОБЕННОСТИ ФОРМИРОВАНИЯ САЖЕНЦЕВ СЛИВЫ, ВЫРАЩИВАЕМЫХ В ПЛОДОВОМ ПИТОМНИКЕ ПРИ КАПЕЛЬНОМ ОРОШЕНИИ

There is currently a lack of capacity in the Russian nursery-garden, as a result of which a significant part of the planting material comes from abroad. Drip irrigation is one of the types of resource-saving technologies that can intensify agricultural production, including in the field of growing planting stock for gardening. The goal of the work was to study the effect of drip irrigation on the formation of plum seedlings grown in a fruit nursery under the conditions of the central Nonblack Soil zone of Russia. Field studies were conducted on the territory of the educational-experimental farm of the Michurinsky Garden fruit-growing laboratory of the Russian State Agrarian University–Moscow Timiryazev Agricultural Academy. A two-factor field experiment was laid in spring 2018. The first factor is the drip irrigation mode; the second factor is the plum varieties (Mashenka and Utro) grafted on cherry plum stock. The results of the experiment show that an irrigation mode with maintaining soil moisture in the range of 80–100% of the lowest moisture capacity with a soaking depth of 30 cm in the first year and 40 cm in the second year is recommended to more rationally use irrigation water and to obtain high-quality plum planting material in the nursery. This irrigation mode was noted to result in the maximum values of the stem diameter, height of seedlings, and leaf surface area.

Fate of urea-15N as influenced by different irrigation modes.

Fertilizer nitrogen (N) is a main pollutant in the agricultural ecosystem, while the fate of fertilizer N influenced by different irrigation modes is not well comparatively investigated. In this study, the distribution of fertilizer N in soil layers and tomato organs as well as its loss under drip, spray and flood irrigation with different quotas of 140, 180 and 220 m3 ha−1 were evaluated quantitatively by using nitrogen-15 (15N) labeled urea (abundance of 19.6%) as fertilizer source. The results showed that the plant 15N, soil 15N and 15N loss accounted for 27.9–47.8%, 38.8–54.0% and 10.3–21.9% of the total applied 15N, respectively. The amount of 15N absorbed by plants was significantly (p < 0.05) higher under drip and spray irrigation in comparison to flood irrigation with the same irrigation quota. The maximum 15N use efficiency and the minimum 15N residual were detected under drip irrigation with quota of 180 m3 ha−1, indicating that the supply and demand of urea-15N was more synchronized under such an irrigation mode. The 15N loss increased obviously as irrigation quota increased. Moreover, the correlation analysis between 15N loss and the possible impact factors indicated that the soil mineral 15N content after irrigation was one important factor influencing the 15N loss. Among the three irrigation modes, spray irrigation caused the lowest 15N loss of 10.3–13.1% when using the same irrigation quota. It was concluded that the irrigation modes have profound impacts on the fate of urea-15N. Irrigation could be used as a regulation pathway of plant N absorption and agricultural N output.

Regularities of beet root crop yield formation based on retrospective data

The article presents a statistical model of the impact of agromeliorative factors, including methods and modes of irrigation on the productivity of beet root crops in the combination of drip irrigation and fine sprinkling (MAV). The experiments were carried out according to a three – factor scheme providing for the regulation of the phytoclimate (factor A): A1 - drip irrigation; A2-drip irrigation together with the management of the phytoclimate by MAV. Hydrothermal regulation of the phytoclimate was carried out using additional equipment with an interval of 1 hour during the entire vegetation period, provided that the air temperature was higher than the biologically optimal 26°C. the parameters of controlling the lowest humidity of HB (factor B) were taken: B1 – 70 %; B2 – 80 %. On the basis of the dispersion statistical analysis of the results of field studies, the following statistically significant shares of their participation in the formation of the crop were established: factor A – 23%, factor B – 29%, factor C – 44%. The revealed joint influence of factors A and C on the variability of the crop of root crops, the share of which was two percent, exceeds the value of the influence of other pair interactions.

Institutional Arrangements and Farmland Rents in India: A Ricardian Analysis

In addition to environmental factors, the welfare of farming communities in most developing countries depends largely on the credibility of organizations that regulate, implement, and protect different institutional arrangements for facilitating coordination between people. This study adopts the Ricardian approach to investigate whether people’s confidence in such local and national organizations is reflected in farmland rents in rural India. By using repeated cross-sectional household and monthly rainfall data, econometric modeling results indicate a positive relationship between farmland rents and a constructed index of confidence in different organizations. Accounting for the potential endogeneity in this index, TSLS results, with a monthly marginal implicit rent (M-MIR) of $13.32 per acre, reveal an even stronger and significant impact. This implies that the M-MIR of farmlands, of people’s confidence in institutional arrangements is equivalent to 83% of the monthly rural poverty line for a five-member household. The instrument selected to address the potential endogeneity in the confidence index is men’s exposure to mass media in the household. Factors controlled for include - households’ participation in community groups, land area, mode of irrigation, seasonal rainfall, village level information on cattle prices, and distance to different amenities. The findings support the critical importance of continued investment in regional and national entities that oversee and implement various institutional arrangements for facilitating greater cooperation within farming communities.

Influence of irrigation mode on winter wheat production and moisture changes of wheat fields under extreme rainfall patterns

This work studied the effect of irrigation measures on water changes and crop growth in wheat fields during extreme drought years with rainfall of only 47.7 mm during the wheat growth period. Field investigation was carried out in the low plains of Hebei Province. In the experiment, six water-saving wheat varieties were used, and five irrigation levels (0 mm, 75 mm, 150 mm, 225 mm and 300 mm designated as T0, T1, T2, T3 and T4, respectively) were set in the spring. Results showed that wheat yield ranged from 70.5 kg/hm2 to 7053.0 kg/hm2. With the increase in irrigation times, yield level gradually increased and was highest under the T4 treatment. The effect of irrigation mode on panicle number was different from that on yield. The T0 treatment group had the smallest panicle number, whereas the other treatment groups showed slight differences and no discernible trend. The range of 1000-grain weight of different varieties of wheat was 33.36–46.68 g. Except for the T0 treatment, all other treatments increased with the increase in irrigation times. The difference between panicle and grain number was irregular and related to varieties. When population difference was large, yield was related to population size. When the population difference was small, yield was correlated with 1000-grain weight. From the perspective of soil water changes, in the late growth stage, the water content of deep soil under T0 and T4 treatments was higher, whereas that under T1 and T2 treatments was lower. This result indicated that T1 and T2 irrigation modes were conducive for the full utilisation of water in deep soil and were efficient water use modes. T1 and T2 were water saving irrigation models in this study. These conclusions can provide a theoretical basis for guiding the selection of irrigation patterns for wheat cultivation during spring.

Factors affecting the change in wheel resistance and track depth of wide-grip sprinkler machines

The operation of sprinkler machines is accompanied by the formation of a track with undercarriages, leading to an increase in resistance to wheel movement and leading to many negative consequences: over-watering of irrigated areas, an increase in energy expended on movement, an increase in soil compaction, etc. The depth of the track and the resistance to wheel movement depend on many parameters: soil moisture, irrigation mode, soil bearing capacity, wheel geometry, etc. But the greatest influence is exerted by the load on the wheel axle and the air pressure in the tires. The article presents the results of laboratory studies of installations that simulate the undercarriage of sprinkler machines, which showed that while maintaining a constant air pressure in the tires, an increase in the axle load of the pneumatic wheel from 0,1 to 1.0 kN leads to an increase in the track depth to 4 cm, and also a linear increase in the resistance to wheel movement. With an increase in the pressure generated by the pneumatic wheel, the permanent deformation, the depth of the track, and, consequently, the resistance to movement of the pneumatic wheel increases. The track depth increases by 20 % with an increase in tire pressure from 0,5 to 1,0 MPa. With a constant load on the axle of the wheel, the resistance to movement of the pneumatic wheel increases on average by 25 % when the air pressure in the tires rises from 0,5 to 1,6 MPa. Optimization of running systems, the ratio of the load on the axle of the wheel, geometrical parameters and characteristics, as well as the air pressure in the tires is an urgent task.

ФАКТОРЫ, УСИЛИВАЮЩИЕ ОТРИЦАТЕЛЬНОЕ ВОЗДЕЙСТВИЕ ДЛИТЕЛЬНОГО ОРОШЕНИЯ НА СВОЙСТВА ЧЕРНОЗЕМА ОБЫКНОВЕННОГО

Purpose: to identify factors enhancing the negative impact of long-term irrigation on soil fertility. Materials and methods. The influence of mineralization and quality of irrigation water on ordinary chernozems (Neklinovsky district), the level of groundwater table on the reclamation state and soil fertility of ordinary chernozems (Bagaevsky district of Rostov region), the structure of crop rotations was studied, and optimal moisture levels for different irrigation modes were established. Results. Long-term use of sulphate-sodium low-mineralized water led to the degradation of ordinary chernozems. They acquired the properties of medium alkaline and medium solonized soils: alkalinity – 1.29 mmol(eq)/100 g, solonetzicity – 7 % of exchangeable sodium from the total soil absorbing complex (SAC), soil bulk density – 1.34 t/m³, humus content decreased by 23 % during its transformation from fulvate-humate to humate-fulvate. The close ground waters table and their mineralization of 5 g/dm³ contributed to secondary salinization. Fertility reproduction is observed only with the introduction of organic fertilizers. The increase in humus content in the alfalfa-corn crop rotation was 0.68 % with the introduction of 60 t/ha of manure after 4 years of corn cultivation in comparison with the humus content after 3 years of alfalfa cultivation, and in the grain feed – 0.55 %. It was found that with an increase of irrigation rate up to 30 %, leaching of exchangeable calcium is observed with a simultaneous increase in the content of exchangeable sodium up to 4 % of the total SAC, which contributes to an increase in bulk density of ordinary chernozem to 1.38 t/m³. In the variant with over-irrigation, the humus content decreased by 0.22 % over 4 years of regular irrigation, and in the variant with the optimal and reduced by 40 and 60 % rates, its amount decreased from 0.04 to 0.07 %, as in dry land. Conclusions. The investigated factors enhance under certain conditions the negative impact of long-term irrigation on the properties of ordinary chernozem.

The biometric indicators and productivity of maize hybrids under different irrigation modes and moisture supply in the Arid Steppe of Ukraine

The biometric indicators and productivity of maize hybrids under different irrigation modes and moisture supply in the Arid Steppe of Ukraine

Methodological approach to development of technology of growing spring wheat under irrigation based on resource conservation with use of imitational model

A methodology of the formation of spring wheat cultivation technology is presented under the optimization of such factors as fertilizers and irrigation. The methodology includes the agroecological verification of spring wheat varieties, adaptation to the imitation model of grain crops, performing a series of numerical experiments, development and solution of the optimization problem of technology resource supply and determination of the optimum operating mode of irrigation. The optimum irrigation regime was based on the use of variations of the imitation model of spring wheat. This version of the model is adapted to the appropriate doses of fertilizers. An irrigation regime conducive to obtaining the required yield was formed as a result of the analysis of the curves of the water status of sowing and infiltration effluent. Consideration of the actual results obtained with the use of optimum irrigation regimes in different years of research contributed to the formulation of the rules for watering purpose. The optimum combination of regulated factors allows to improve significantly grain quality, protein up to 17.0 % and gluten up to 41.5 % content.

DEVELOPMENT OF APPROACHES TO WATER RESOURCES MANAGEMENT IN THE LOWER KUBAN TO ENSURE WATER USER REQUIREMENTS IN LOW‐WATER YEARS†

ABSTRACTThe Lower Kuban River Basin experiences an acute shortage of water resources during the growing season. Every third year is a low‐water period. The complex layout of rice irrigation systems requires reliable forecasting and skilful management. This article presents the results and methodology for determining the optimal operational modes of the Lower Kuban irrigation and drainage systems based on multi‐criteria analyses and trade‐off theory that ensure the reliable functioning of the water resource system taking into account contradictory requirements of water users and restrictions aimed at preserving the Kuban River Basin ecosystem.The methodology is based on multi‐criteria analysis and hydrodynamic modelling with the application of the ‘operating structures' module, which, according to a given hierarchy of priorities, allows the water users to fulfil the requirements for discharges and water levels during the determined time period at water intake sites and outlets within the river network. The developed computational technology allows a reasonable compromise to be reached in the process of negotiations between water users and water basin authorities. © 2019 John Wiley &amp; Sons, Ltd.