Irrigation water use efficiency

considerable room for improvement. The Moran’s I of MWP was around 0.400 and it has a spatial distribution pattern that does not change over time. The temperature and precipitation are the primary factors that affect the MWP, which are the primary reasons for the significant aggregation of the MWP in space. In addition, the impact of the fertilizer and agricultural machinery power per sown area on the MWP cannot be ignored, and the MWP can also be further promoted by improving agricultural production conditions. Given the pattern of the temporal and spatial distribution of MWP, each region should develop specific strategies to improve the irrigation water use efficiency on their own water resource endowments and the extent of irrigation development, ensure the national food security and develop the sustainable use of water resources. Improving irrigation efficiency and reducing irrigation water per unit area is a direct measure to improve MWP. In addition, ameliorating crop varieties and raising crop yield can also contribute significantly to the promotion of regional MWP.

In this respect, reforms were undertaken since the beginning of the 90’s in order to improve the irrigation water use efficiency (IWUE) and to enhance the overall performance of the sector. Three important reforms are (i) the modernization of collective irrigation systems management by enhancing the role played by water users associations (WUA) and by promoting the participation of users in all management aspects, (ii) reformulating the water pricing system by introducing the cost recovery objective and (iii) developing incentives to enhance and promote the adoption of water saving technologies at farm level.

Two field experiments were carried out during growing seasons 2010 and 2011, it executed in research farm of national research center in Nubaryia region, Egypt to study the effect of pulse drip irrigation and mulching systems for saving water, increasing and improving yield of soybean. The study factors were, pulse drip ir- rigation technology (adding of daily water re- quirements on 4 times, 8 times, 12 times com- pared with adding of daily water requirements on 1 time) and mulching systems (covering the soil with black plastic mulch “BPM”, rice straw mulch “RSM” and the control treatment was soil surface without mulch “WM”). The following pa- rameters were studied to evaluate the effect of pulse drip irrigation and mulching systems: 1) Soil moisture distribution in root zone, 2) Growth characters of soybean plant, 3) Yield of soybean, 4) Irrigation water use efficiency of soybean “IWUE soybean”, and 5) Oil content and oil yield, 6) Protein content and protein yield, 7) Economical parameter. According to the eco- nomical view and the results of statistical ana- lysis for effect of pulse drip irrigation and mul- ching systems on yield, quality traits and IWUE soybean indicated that, applying the irrigation requirements on 8 pulses/day with using BPM is the best conditions because under these condi- tions was occurred the highest value of yield, quality traits and IWUE soybean and there was significant deference between this case and other treatments. Where, pulse irrigation tech- nique increase from water movement in hori- zontal direction than vertical direction hence

When the soil-water content exceeds the porosity the result is runoff or deep percolation. At saturation the pore space is completely filled with water. After allowing the soil to drain for 1-2 days, “field capacity” is reached. “Field capacity” is the amount of water that the soil can hold against gravity. When irrigating, it is best to never exceed field capacity to maximize irrigation water use efficiency. The lower level of soil-water content at which a plant can extract water is termed the “permanent wilting point”. At a soil-water content at or below the “permanent wilting point” plants can no longer extract water from the soil resulting in plant death. The difference in soil-water content between field capacity and permanent wilting point is termed “plant available water”. As the soil-water content decreases toward the “permanent wilting point” the water grows increasingly difficult for the plant to extract. Therefore, a “management allowable depletion” (MAD) level above the wilting point should be set to minimize plant water stress. The difference between field capacity and MAD is known as readily available water (RAW) (Allen et al. 1998) and to limit plant water stress and maximize yield the soil water content should be maintained above MAD. Researchers have used several different methods to maintain soil-water content between MAD and field capacity.

Distance from the source of irrigated water to farm (m) Negative Ownership of irrigation system Positive Education level (dummy variable) Positive Farmer’s irrigation experience (years) Positive Extension contact (dummy variable) Positive Access to credit (dummy variable) Positive

Maize (Zea Mays L.) is one of the most important food crops worldwide. In Ethiopia, it is one of the leading food grains selected to assume a national commodity crop to support the food self- sufficiency program of the country. Maize is fairly sensitive to water stress and excessive moisture stress. This is due to variation in sensitivity of different growth stages to water stress. The study was conducted to determine the water use efficiency of maize under deficit irrigation practice without significant reduction in yield and to identify crop growth stages which can withstand water stress. The experiment was conducted at the Alamata Agricultural Research center experimental site Kara Adishabo Kebele, Raya Azebo district. The experiment was laid out in randomized complete block design (RCBD) with three replications and six levels of irrigation water applications as possible treatments. Analysis was done to yield and water use efficiency of maize using R statistical software and the mean difference was estimated using the least significant difference (LSD) comparison. The highest grain (33.72qt/ha) and biomass yield (148.4qt/ha) was obtained from the 50% deficit irrigation at late growth. The maximum irrigation water use efficiency was obtained from both 50% deficit at all the four growth stages (0.5418 kg/ha) and at 50% deficit at late growth stage (0.446 kg/m3). And by comparing the grain yield obtained at the 50% deficit at

T HIS experiment was performed during the summer seasons 2015 - 2016, at a private farm in the El Kasasin area, Ismailia Governorate, Egypt, to study the effect of deficit irrigation (DI) during growth stages compared to full irrigation (FI) under surface drip (SDI) and sub- surface drip (SSDI) on marketable yield (Ym), plant quality parameters, water use efficacy (WUE) and irrigation water use efficiency (IWUE) of carrot (Daucus carota L.) crop. The experimental design was a split plot design with three replicates. The obtained results indicated that, the values of quality parameters, Ym, ETa for carrot roots decreased with increasing DI during the growth stages especially (initial and development stages) except L-ascorbic acid content and total sugar content which increased with increasing DI under SDI and SSDI for both seasons. In addition; the maximum values of Ym for carrot roots were 8.38 and 8.56 Mg fed -1 , respectively, under the FI (I=100, D=100, M=100, L=100%) and SSDI treatment.

HE INTELLIGENT irrigation technique is a valuable tool for scheduling irrigation and quantifying water required by plants to achieve water savings. Field experiments were carried out in New Salhia area, El- Sharqia Governorate, Egypt, at (30° 18` N: 31° 23` E. 27 m a.s.l) during the summer season of 2015.The main objectives were to investigate the effectiveness of the intelligent irrigation technique (IIT) (Hunter Pro-C (H)) which was irrigated automatically on water use efficiency (WUE) and irrigation water use efficiency (IWUE) for irrigation scheduling of cucumber (Cucumis sativus Hayle) and pepper (Capsicum annuum) crops. The intelligent irrigation technique, (IIT) was implemented and tested under surface, (SDI) and sub-surface drip irrigation systems, (SSDI). The results obtained with these systems were consequently compared to that of the irrigation control technique (ICT), which was irrigated manually based on crop evapotranspiration (ETc) values. The results revealed that cucumber and pepper growth parameters except pH of juice were significantly increased by IIT under SSDI. In addition; IIT under SSDI conserved 34 and 24% of total applied irrigation water for cucumber and pepper respectively. Moreover, the results showed that the IIT under SSDI recorded significant increase 12 and 13% for marketable yield Ym of cucumber and pepper respectively. While, the results reported that the WUE values using IIT under SSDI were significantly increased by about 30 to 33% for cucumber and pepper respectively. The results confirmed also that the values of IWUE at IIT under SSDI were significantly increased by about 49 to 39 % for cucumber and pepper respectively. The intelligent irrigation technique may provide a valuable tool for scheduling irrigation in cucumber and pepper farming and may be extendable for use in other similar agricultural crops. These results show that this IIT could be a flexible, practical tool for improving scheduled irrigation. Hence, this technique can therefore be recommended for efficient automated irrigation systems that produces higher yield and conserves large amounts of irrigation water.

The evapotranspitation was determined from sowing to harvest of crops according to the following water soil balance ET0 = ΔS [variation in soil water storage (mm)] + P [rainfall (mm)] + I [irrigation (mm)]. The soil water storage was measured by neutron probe (mm) before and after irrigation supply. During the time of experiment, drainage and runoff, have been absent during the period of experiments. Water was applied when evapotranspira- tion (ET0) from the crop, determined by Doorenbos and Kassam [10], reached 80 mm. In addition, in the last 5 years agreement was found from comparison of the ET0 value determined by meteorological instruments with those simulated by Decision Support System embodied in the AQUATER software for irrigation management in semi-arid Mediterranean areas [11].

and cadmium are highly toxic though at relatively low concentration. They interfere in enzyme action by replacing metals ions from metallo-enzymes and inhibit different physiological processes of plants resulting in poor growth and yield parameters (Kadar and Kastori, 2003; Palacios et al, 1998; Seregin and Kozhevnikova, 2006). However, biological treatment revealed better growth and yield parameters due to accumulation of such heavy metal ions by microbial uptake mechanisms (Ahluwalia and Goyal, 2007). Though, chemical treatment is being currently carried out in the industries that are under pressure to reduce pollutant load, the water that is drained into the streams is not significantly improved in qualities, in terms of toxicity. It is evident in the present study that the chemically treated wastewater is toxic to the plants. However, in biological treatment, though the clarity of the treated water is not to the desired re-use standard due to the biomass accumulation, the detoxification of the treated water is revealed by the phytotoxicity and yield parameters in the plants under study.Since water is a commodity of high demand in the country, with these limitations, one has to turn to non-conventional resources to meet the irrigation- water demand. Since the disposal of untreated textile wastewater is a major problem in urban areas, applying the bioremediation to textile wastewater can make crops grow better due to presence of various nutrients such as N, P, Ca and Mg (Kannan et al, 2005; Khan et al, 2003). Based on the above results, treatment of wastewater can be considered as an effective method in reusing the wastewater from industry for irrigation purposes.

Husk tomato seeds were sown in trays with 50 and 200 cavities. The substrate used was peat moss and vermiculite (1:1) in 107 L packets. Trays were covered with dark plastic and stacked. After the seeds germinated on the third day, the trays were unstacked and transferred to the nursery. The seedlings were watered with a nutrient solution (Steiner) diluted to 50% to avoid burn injury. Seedlings were transplanted at 30 days after sowing (Table 2). The characteristics of seedlings at the time of transplant were as follows: 10 cm in height, 2.7 mm in diameter and at least six fully expanded true leaves. The planting arrangement of the seedlings with drip irrigation and plastic sheeting was 1.5 m between rows and 0.40 m between plants (Figure 2) for a population of 16,500 plants per hectare.

The Guadiana Basin is characterized as a rural territory with low population density where water and irrigation have for decades been seen as the main route to modernize the re- gion and prevent land abandonment and depopulation. In the last forty years, the area in irrigation had expanded by 300 % (from 140 730 ha in 1970 to 400 431 ha in 2010; see Fig. 5). Irrigation development has increased agricultural produc- tion and crop diversification, enhancing income generation and favoring labor creation in rural areas (Varela-Ortega, 2011). However, it has been achieved at the expense of nega- tive environmental impacts, namely alteration of natural hy- draulic river regimes, reduction of in-stream flow volumes, disappearance of riparian vegetation, over-pumping of frag- ile aquifers, and the degradation of internationally protected water-dependent natural spaces (e.g., Tablas de Daimiel Na- tional Park in the upper part of the basin, and Sites of Com- munity Importance and Special Protection Areas in the mid- dle and lower part of the basin), which have reduced the resilience of the socio-ecological system in the river basin (Blanco-Gutiérrez et al., 2011, 2013). These and the trends shown in Fig. 6 represent examples of the efficiency and scale paradoxes. In 1987, La Mancha Occidental and Campo de Montiel aquifers, the largest and most important in the basin, were legally declared overexploited with strict regula- tory measures applied to both public and private water users. All water resources in Spain have been public property since 1986, when the Spanish Water Act 29/1985 made ground- water ownership public. In addition to surface water users, groundwater users were granted administrative concessions of water use rights defined by specific water allotments. Yet, those who wished to remain in the private property regime were allowed to do so. Therefore, public and private regimes still coexist.

For example, the ratio of cotton stem biomass under T2 was obviously lower than that of other treatments on DAS 62, while the ratio of cotton leaves under T1 was distinctly higher than that under T2 and CK at the same time, but there were no distinguishing differences in the relative biomass reproductive organs across different treatments (p>0.05). On DAS 101, the proportion of leaf biomass under T4 was significantly greater than that under other treatments (p≤0.05). In other words, compared with CK, a greater water supply promoted the distribution of dry matter towards the leaves, whereas it inhibited the distribution of biomass into reproductive organs. Above-ground biomass distributed in vegetative organs under T3 showed the smallest proportion at 136 DAS. In contrast, a greater proportion of total biomass was apportioned to reproductive structures under T3, which benefited the formation of economic yield. This clearly illustrates the importance of adequately regulated irrigation scheduling for cotton growth.

According to the study conducted by Yigezu [1], Irrigation method is one of the most important variables in explaining the variation in both technical and irrigation water efficiencies. Comparison between irrigation methods reveals that shift from the traditional surface canal irrigation to modern irrigation methods, particularly sprinklers, leads to 19% and 9% higher output oriented technical efficiency and irrigation water use technical efficiency, respectively. This finding is consistent with the views of Allan (1999) [2], in that water can be used more effectively by utilizing more advanced irrigation technologies (e.g., drip irrigation instead of water spreading).

In the NCP, since the 1970s, annual precipitation has been declining (Sun et al., 2010). Therefore, effective use of irrigation water is a key for sustainable development of winter wheat production. Under field conditions, crops WUE is determined by transpiration rate through leaves and water absorbing capacity through roots; hence, as for crops effective use of water in essence, is to achieve the optimum balance conditions of the structure and function of crops canopies and roots (Chen et al., 2005; Gao et al., 2007). In the NCP, as the saving water agriculture boots, to ensure the sustainable development of agriculture and effective use of water resources, it is in urgent need to study the key techniques and basic theory concerned root-shoot balance.

Using irrigation as a means of aiding rooting depth is a dynamic process and it not fully understood (Whalley et al. 2006). When a plant is in a dry environment it will exert resources into growing roots into the soil looking for water. However, in texture contrast soils, the strength of the clay subsoil increases as it dries. The soil then reaches a point when roots cannot penetrate through the subsoil as it becomes too hard. Therefore the roots may not sufficiently reach water that is stored deeper in the profile, which has shown to have a large impact on grain yield and WUE (Kirkegaard et al. 2007). Conversely, when the soil is wet, particularly the upper layers, roots may not grow to access water deeper in the profile. Moisture levels may be sufficient for the crop growth at that particular stage of development however, wet soils have a lower penetration resistance and therefore this is the ideal time for roots to extend deeper into the profile. However, it is important to find a balance where the crop is forced into root exploration without the onset of high penetration resistance in the soil. This is where irrigation, particularly earlier in the growing season, may be used as a tool to influence root growth by increasing soil water availability later in the season as well as provide sufficient amounts of water for successful crop development.

days to decrease soil water content to 30% below saturation although the disappearance of standing water was enhanced by soil desiccation. Consequently, 26 irrigation events were applied to soils for reaching the upper limit. The difference in water consumption, at each irrigation event, should be mainly from the difference between the low limit of irrigation regimes practiced in this study, while soil cracking, standing water depth, evapotranspiration, and percolation rate also could be reasons for such difference. Therein, percolation of water was increased with a large depth of ponding water. Cracks were also the motivation for a considerable increase in the irrigation water inputs at the time of irrigation.

becoming increasingly important in arid and semi-arid regions with limited water resources. Furrow irrigation is the most widely used system in Ethiopia and is characterized by low efficiency. The objective of this research study was to investigate the effects of alternative and fixed furrow irrigation system onion yield, WUE, irrigation water productivity, and economic return as compared with conventional method.This experiment was conducted for the last two years in Misrak Azernet Berbere woreda, Ethiopia. The experiment had three levels of treatments (alternative, fixed and conventional irrigation system) and which were arranged in RCBD with three replications. Different data were collected and analyzed using SAS software in probability of 5% confidence level. From the result water saved alternate furrow and fixed irrigation with 20% and 30% could save irrigation water applied. With respect to water use efficiency; alternative furrow irrigation results maximum values relative to fixed and conventional irrigation in both years. In the case of net return (NR) interaction of FFI and CFI, the highest was produced by alternate furrow AFI. Finally the finding indorses that farmers can practice alternate furrow irrigation (AFI) with 20% water saving as a best option, with maximum yield compared convectional furrow irrigation having full water application.

The field experiment was conducted using a randomized complete block design with eight irrigation treatments (T1–T8) and four replications. Each treatment received a seasonal irrigation allocation, which ranged from 53 to 356 mm in 2005 and from 22 to 226 mm in 2006 (Table 1). The aim was to develop well-defined crop response functions to irrigation, ranging from near dryland to over-irrigated conditions. A dryland treatment was not included because some irrigation water was needed to apply nitrogen fertilizer. Irrigations were scheduled to avoid or minimize water stress and deep percolation. The target was to keep the percent soil water depletion in the crop root zone below 50% of the total available soil water for as much of the season as possible. Another target was to maintain a soil water depletion of at least 50 mm to store potential rainfall and avoid deep percolation, which was especially important for treatments receiving and excessive allocation. For treatments with a deficient allocation to meet irrigation requirements for the entire season, the strategy was to minimize stress during the peak ETc period (in July), allowing stress later in the season. Once irrigation started, all treatments were irrigated at the same time until the allocation for a given treatment ran out. Irrigations were usually applied two to three times a week. In 2005, irrigations started in mid- July, since rainfall and stored soil water provided adequate moisture for crop development earlier in the season. In 2006, irrigation started in June due to drier soil conditions compared with 2005.

To try to remedy the uniformity issues, the 7005 sprinklers were removed and replaced with 8005 models fitted with nozzles slightly larger than that used in the 7005’s. The factory specifications stated that the 8005 heads were capable of a throw radius of twenty three metres, two metres longer than the 7005’s. It was hoped with the longer throw radius and the use of the larger nozzle that the droplet size would be slightly larger and would be able to travel further distances under windy conditions. When removing the 7005 sprinkler heads it was found that many of them were installed at incorrect depths and angles. In some cases the sprinkler heads were installed at a distance from the surface so deep that the stream of water that the sprinkler produced was being restricted because it was spraying straight into the side of the surrounding turf. The angle that the many sprinklers were operating at also brought cause for concern. In some cases the sprinkler heads were approximately 20° off the proper working angle. This caused the sprinkler to spray at an angle too low for half of its designed target area and too high for the remaining half. Not operating at the designed angle causes the throw radius to be changed and when the sprinkler is spraying higher in the air than designed, the wind is going to have a greater effect on your overall