Soil Moisture Depletion Levels Research Articles

Effect of Deficit Irrigation and Mulch on Field and Water Productivity of Tomato Under Drip Irrigation at Ambo Agricultural Research Center, West Shewa, Ethiopia

Ethiopia produces far fewer tomatoes than the world average due to poor management techniques. It was found that the soil moisture and agroclimatic conditions affected how tomatoes reacted to water management during irrigation. In order to assess the impacts of irrigation level and mulch types on the yield, yield components, water productivity, and economic return of drip irrigated tomato production, a field experiment was carried out at the Ambo Agricultural Research Center Farm Site in 2021–2023. The experiment was a two-factor factorial experiment arranged in a randomized complete block design. The two factors were the four irrigation levels (55%ETc, 85%Etc, 70%ETc and 100%ETc) and three mulch types (no mulch, wheat straw mulch, and white plastic mulch). The two-year data on fruit yield, yield components, and water productivity were subjected to analysis of variance using SAS 9.4 software with a significance level (p≤ 0.05). least significant difference test was applied for statistically significant parameters to compare means among the treatments. The best soil moisture depletion levels, as determined by statistical analysis, are 100% ETc, 85% ETc, and 70% ETc, with marketable fruit yields of 56,405 kg/ha, 45,331 kg/ha, and 41,769 kg/ha, respectively. As for mulch types, the best practices are wheat straw mulch and white plastic mulch, with marketable fruit yields of 45,721 kg/ha and 44,514 kg/ha, respectively, for the study area. However, the results of the partial budget analysis results showed that, with net incomes for onion production in the research region of 1,350,930 ETB/ha and 1,367,071 ETB/ha, respectively, 85% ETc and wheat straw mulch are the economically optimal methods.

RESPONSE OF SUNFLOWER CROP TO DIFFERENT LEVELS OF SOIL MOISTURE DEPLETION

The amount of water utilized by the plant has a significant impact on its yield. In this regard, yield response factor (Ky) permits measuring yield decline as a function of evapotranspiration. As a result, the purpose of this study was to calculate Ky for the sunflower crop grown in North Nile Delta, Egypt and to calculate economic water productivity. Seasons 2021 and 2022 were studied. The experiment used a complete randomized block design with three replicates. W1 (50-55%), W2 (55-60%), and W3 (60-65%) maximum allowable depletion of available soil moisture (MAD of ASW) treatments were used. In total, the average two seasons (0.52 and 0.61) found for sunflower crop under W2&W3, respectively, demonstrated its strong sociability to water deficit. Its yield is substantially impacted by water availability, with average 0.65 & 0.47% loss in yield for every 1% reduction in evapotranspiration with w2 and w3 treatments, respectively. The treatment without stress, w1 (50-55% MAD of ASW), yielded the highest grain yield. However, after considering water and irrigation costs, it could conclude that other stressed treatments, W2&W3, were more cost-effective.

Determination of Optimal Irrigation Using Soil Moisture Depletion on Yield and Water Productivity of Onion at Odo Shakiso District, Southern Ethiopia

Irrigation scheduling is the use of water management strategies to prevent over-application of water while minimizing yield losses due to water scarcity or drought stress. The experiment was conducted in Odo Shakiso district at a farm during the 2020/21 and 2021/22 irrigation seasons with the aim of determining the optimal irrigation schedule for yield, yield component and water productivity of onions based on the available soil moisture depletion levels. The experiment was performed in RCBD with three replicates randomly assigned to experimental plots with treatments. Five available soil moisture depletion levels (20% ASMDL, 40% ASMDL, 60% ASMDL, 80% ASMDL and FAO recommended ASMDL) were used for treatment. Results from two years of research showed that different levels of available soil moisture had a significant impact (P<0.05) on bulb diameter, bulb weight, unmarketable onion yield, marketable onion yield, and water productivity. However, different soil moisture depletion did not show a significant difference in plant height. The highest onion diameter (4.25 cm) and marketable onion yield (363.9 qt/ha) was recorded at 60% ASMDL. The highest water use efficiency at marketable onion yield (9.487 kg/m³) was also achieved at 60% ASMDL, which was statistically comparable to the FAO-recommended ASMDL treatment. On the other hand, the minimum water use efficiency (6.234 kg/m³) was recorded at 40 percent ASMDL. Therefore, based on the results of the current experiment, it is recommended to use 60% ASMDL under a furrow irrigation system for onion cultivation in areas around Shakiso and similar agro ecologies as it is the best option to increase yield and water use efficiency for onion production.

Determination of Optimal Irrigation Scheduling for Coffee (Coffee arabica L.) at Gera, South West of Ethiopia

Afield experiment was carried out from 2011 to 2018 cropping seasons at experimental site of Gera agricultural research sub-center to investigate the effect of soil moisture depletion and to identify optimal soil moisture depletion level on growth, yield and water productivity of coffee Arabica (coffee Arabica L.) of variety 74165. The treatments consists of five allowable soil moisture depletion level (ASMDL), i.e, 60% ASMDL, 80% ASMDL, 120% ASMDL, 140% ASMDL and control irrigation of 100% ASMDL. These five treatments were laid out in complete randomized block design with three replications. The irrigation water was applied based on allowable soil moisture depletion of (p=40%) considered for coffee Arabica. The over year analysis of variance showed that soil moisture depletion level significantly (P&lt;0.05) affected coffee yield and water productivity. The average highest coffee yield of 2330 Kg/ha was obtained from the 120% ASMDL by applying 10145 m 3 /ha of water, while the FAO recommended treatment of 100% ASMDL produced the lowest yield of 1780 Kg/ha. The 60%, 80%, 100% and 140% treatments were not statistically significant from each another. Therefore, 120% ASMDL treatment gave above mean value of yield and water productivity and hence can be used as the allowable soil moisture depletion for coffee Arabica (coffee Arabica L.) in a coffee growing area of Gera. Keywords: ASMDL, Irrigation regime, coffee DOI: 10.7176/JNSR/13-7-03 Publication date: April 30 th 2022

Determination of optimum irrigation scheduling for sorghum in Benna-Tsemay Woreda, Southern Ethiopia

Scarcity of water is the most severe constraint for sustainable development of agriculture in arid and semi-arid areas. Hence, novel irrigation water application systems need to be developed so that high crop yield and water productivity per unit of land can be increased. Thus, the field experiment was conducted with the objective of determining the effect of different soil moisture depletion levels on yield and water use efficiency of sorghum crop in Benna-Tsemay woreda at Enchete kebele, Southern Ethiopia. The experiment was conducted for two consecutive years (2019-2020). It was arranged in RCBD with three replications and treatment was rated for five levels of available soil moisture depletion (ASMD), where T1 = 60%, T2 = 80%, T3 = 100%, T4 = 120%, and T5 = 140% of ASMD. Analysis of variance has shown that yield and water use efficiency of sorghum crop was significantly (P &lt; 0.05) affected by irrigation scheduling. As observed in this study, the most economically attractive and environmentally accepted for small scale farmers with tolerable cost of production and higher net benefit was obtained by application of T3 (100% ASMD) under conventional furrow irrigation system. Therefore, for this particular sorghum crop (teshale variety), it could be concluded that increased water saving and water productivity through irrigation at 100% ASMD under conventional furrow irrigation system can solve the problem of water shortage and would ensure the opportunity of further irrigation development in the study area and similar agro-ecology. Int. J. Agril. Res. Innov. Tech. 11(2): 95-102, Dec 2021

Determination of Optimal Irrigation Scheduling for Onion (&amp;lt;i&amp;gt;Allium cepa&amp;lt;/i&amp;gt; L.) in Gumara Scheme, North Western Ethiopia

The experiment was performed at Gumara irrigation scheme farm in the 2017/18 and 2019/19 irrigation seasons, with the objective of determining the optimum irrigation schedule based on the available soil moisture depletion levels. The experiment was carried out in RCBD with three replications, randomly assigned to the experimental plots with treatments. Six available soil moisture depletion levels (60, 80, 100, 120, 140, and 160%) were use. The results obtained of two years of research showed that different rates of levels of soil moisture available had a very highly significant effect (P<0.0001) on bulb mass, bulb diameter, marketable yield, and water productivity. The highest marketable bulb yield and water productivity (35222.2 kg ha^-1 and 7.06kg/m³) were recorded at 80% and available soil moisture depletion levels (ASMDL) and also the lowest non-marketable bulb yield (1513.9 kg/ha) was recorded at 80% ASMDL. However, the lowest marketable yield, lowest water productivity and highest non-marketable bulb yield (28722.2 kg ha^-1, 5.29 kg/m³ and 5236.1 kg /ha) was recorded at 160 percent ASMDL Very highly significant (P < 0.0001) plant height and bulb length differences were observed due to the treatments. The highest plant height and bulb length were recorded at 60 per cent AMADL (66.33 cm and 5.62 cm respectively). However, different soil moisture depletion levels showed no significant difference in the stand count of onion. The highest efficiency of water use on onion yield (7.06 kg/m³) was attained at 80 percent ASMDL, whereas the minimum efficiency of water use (5.29 kg/m³) was recorded at 160 per cent ASMDL. Therefore, based on the findings of the current experiment, it is recommended that using 80%ASMDL for furrow irrigation system for onion to be grown in areas around Fogera and similar agroecology as best options to increase yield and water use efficiency for the production of onion.

Optimal Irrigation Scheduling for Pepper (Capsicum annuum L.) at Gidara Condition, Central Rift Valley of Ethiopia

The wise use of irrigation water relies on understanding the exact crop water demand and its application which help to boost agricultural water productivity. Proper irrigation scheduling comprises crop water demand and the rifling frequency of the required water amount. Therefore, this activity was aimed at determining the optimal irrigation regime for pepper. The trial was carried out during 2016 and 2017 to determine the optimal irrigation regime of Pepper (Mareko Fana variety) at Gidara trial site of Melkassa Agricultural Research under five soil moisture depletion levels at which the next irrigation is given: 60% ASMDL, 80% ASMDL, 100% ASMDL, 120% ASMDL and 140% ASMDL). The allowable soil moisture depletion level (100% ASMDL) was scheduled to be refilled when 30% of the total available soil moisture was depleted. The result revealed that there was significant difference in plant height, yield and water productivity among treatments at 5% level of significance. The maximum yield and water productivity were observed in 60% ASMDL treatment. Using depletion levels of 60% and 80% of the recommended soil moisture depletion levels has increased the water productivity significantly. Hence, as much as the total water to be applied throughout the growth period is similar it is better to irrigate pepper frequently with smaller amount. Keywords: Allowable soil moisture depletion level, Irrigation interval, Irrigation regime, Pepper, Water productivity DOI: 10.7176/JEES/12-1-02 Publication date: January 31 st 2022

Niveles de agotamiento de la humedad aprovechable del suelo en el rendimiento del girasol

ntroduction: Optimizing the irrigation water resource is essential due to its scarcity, so it is therefore important to consider efficient crops such as sunflower. Objective: To estimate the sunflower grain yield at different levels of available soil moisture depletion to estimate water use efficiency (WUE) of the crop under different water conditions. Methodology: Seven treatments resulting from four soil moisture levels (40, 60, 60, 80 and 100 % of available soil moisture [ASM] and two periods of sunflower growth (from emergence to the beginning of flowering [first stage] and from flowering to physiological maturity [second stage]). Results: The highest grain yield (5.5 t·ha-1) and WUE of (0.922 kg·m-3) were recorded in the 60-60 % ASM treatment in the first and second stages of sunflower development, and by consuming 62.8 cm of water. Limitations of the study: The results should not be extrapolated to conditions outside the study levels. Originality: To generate research methodologies to quantify, in a more realistic way, the relationship of yields with crop water requirements. Conclusions: The highest WUE in sunflower (0.922 kg·m-3) was recorded when it consumed 31.4 and 28.12 cm of water, with 58.8 and 60.5 % of ASM in the first and second stages, respectively, which was similar to the 60-60 % treatment.

Evaluation of Some Drought Tolerance Criteria in Locally Gynoecious Cucumber (Cucumis Sativus L.)

A field experiment was carried out in an unheated plastic house in the College of Agriculture-University of Anbar/Ramadi – Iraq in the Autumn season 2018 and Spring season 2019, to evaluate some drought tolerance criteria for three locally hybrids of cucumber (H2, H3, H4) compared with Local hybrid (H1) Certified by Iraqi Ministry of Agriculture under three levels of soil moisture depletion (30%, 50%, 70%) were calculated on the basis of available water. Six criteria were used (Tol, MP, SSI, YSI, YI, GMP) to determine drought tolerance of planted cucumber hybrids. Results showed that the depletion level (30%) gave highest productivity in 2018 and 2019 (3.397, 5.190 Kg plant−1) on the respectively, whereas the lowest yield (3.061, 3.857 Kg plant−1) on the respectively for 70% depletion level. The hybrids H1 and H3 achive highest yield (3.488, 3.260 Kg plant−1) on the respectively in 2018, while the highest yield in 2019 was (4.782 and 4.758 Kg plant−1) for H3 and H1 hybrids on the respectively without significant differences. H4 hybrid gave the lowest yield in the two seasons with significant difference in comparison to H3 and H1. The results also showed that the locally producted hybrid H3 distinguished in most drought tolerance criteria compared with registered hybrid (H1) and was considered as a most tolerance to stress, whereas H1 hybrid the most sensitive to stress

Optimal Irrigation Scheduling for Pepper (Capsicum annuum L.) at Gidara Condition, Central Rift Valley of Ethiopia

The wise use of irrigation water relies on understanding the exact crop water demand and its application which help to boost agricultural water productivity. Proper irrigation scheduling comprises crop water demand and the rifling frequency of the required water amount. Therefore, this activity was aimed at determining the optimal irrigation regime for pepper. The trial was carried out during 2016 and 2017 to determine the optimal irrigation regime of Pepper (Mareko Fana variety) at Gidara trial site of Melkassa Agricultural Research under five soil moisture depletion levels at which the next irrigation is given: 60% ASMDL, 80% ASMDL, 100% ASMDL, 120% ASMDL and 140% ASMDL). The allowable soil moisture depletion level (100% ASMDL) was scheduled to be refilled when 30% of the total available soil moisture was depleted. The result revealed that there was significant difference in plant height, yield and water productivity among treatments at 5% level of significance. The maximum yield and water productivity were observed in 60% ASMDL treatment. Using depletion levels of 60% and 80% of the recommended soil moisture depletion levels has increased the water productivity significantly. Hence, as much as the total water to be applied throughout the growth period is similar it is better to irrigate pepper frequently with smaller amount. Keywords: Allowable soil moisture depletion level, Irrigation interval, Irrigation regime, Pepper, Water productivity DOI: 10.7176/JNSR/12-4-01 Publication date: February 28 th 2021

Determination of Optimal Irrigation Scheduling for Maize (Zea Mays) at Assosa District, Benishangul Gumuz Regional State, Ethiopia

Knowing the appropriate time of irrigation and the amount of water applied to the crop is essential to increase yield and water productivity. There was no research activity which was conducted in Assosa district regarding to optimal irrigation scheduling of maize before this study. Therefore, this study was conducted to evaluate the response of maize to irrigation regime( when and how much) and determination of water productivity. Field experiments were conducted in two consecutive years. The experiment had five treatments which were, Soil moisture depletion levels (SMD1=60% of ASMDL, SMD2=80% of ASMDL, SMD3=100% of ASMDL,SDL4= 120% of ASMDL and SMD5= 140% of ASMDL) with RCBD experimental design. Reference evapotranspiration, crop water and net irrigation requirements were calculated. The results were indicated that yield and water productivity were significance at SMD3 or 100% available soil moisture depletion level of maize variety of BH-540. Hence applying irrigation water when the available soil moisture content reaches at critical depletion and 444.2mm total net depth of water was contributed. Keywords : Water requirement, Irrigation scheduling, Water productivity, Maize, Assosa DOI: 10.7176/JNSR/12-3-02 Publication date: February 28 th 2021

Determination of Optimal Soil Moisture Depletion Level for Stevia (Stevia Rebaudiana Bertoni) at Wondo Genet, South Ethiopia

The study was conducted based on the objective to evaluate the optimal soil moisture depletion level of stevia (Stevia rebaudiana Bertoni). Six levels of soil moisture depletion (20, 30, 40, 50, 60, and 100%) with four replications were used in a randomized complete block design. Different levels of total available water depletion significantly (p<0.05) affected all recorded yield and yield components. Significantly highest plant height, fresh and dry leaf weight, fresh and dry stem weight, aboveground fresh and dry biomass, and water productivity were obtained as stevia was irrigated below 40% TAW depletion level. However, water productivity was decreased both at higher and lower depletion levels and higher was at 30 and 40% depletion levels. The pooled mean revealed that irrigating stevia under different soil moisture depletion levels had a significant (p<0.05) effect on fresh leaf weight, fresh stem weight, dry stem weight, fresh biomass, and water productivity. Moreover, plant height, dry leaf weight, and dry biomass of stevia were also highly significantly (p<0.01) affected due to different soil moisture depletion levels. The maximum plant height (23.95 cm), fresh leaf weight (3300.3 kg/ha), fresh stem weight (1213.3 kg/ha), fresh biomass (4513.6 kg/ha) and water productivity (1.92 kg/m3) were recorded at 30% TAW. Moreover, the maximum dry leaf weight (1155.8 kg/ha), dry stem weight (869.0 kg/ha) and dry aboveground biomass (2024.7 kg/ha) were recorded at 40% TAW. On the other hand, the minimum growth, yield and yield component, and water productivity were recorded at 100% TAW. The current study revealed that irrigating stevia after 40% of the total available water in the soil depleted could be practiced in the study area and similar agroecology and soil type as the wider irrigation interval could be achieved without significantly affecting yield and water productivity.

Fertigation in citrus, a toolkit for sustainable quality production

Techniques and managements of perennial fruits production are nowadays directed towards the need to conserve resources, energy and a commitment to the environment. In this sense, fertigation has risen as a valuable tool in recent years spreading around the world in major fruit belts. The million dollar question strikes why fertigation out-performs conventional basin method of irrigation carrying fertilizers. Citrus trees do not exhibit visible symptoms of water stress until most of the available soil moisture has been depleted. However, fruit set can be adversely affected at soil moisture depletion levels of only 40 to 50 percent, particularly from pre-bloom through June. Consequently, extensive research in the citrus production areas has led to the recommendation that water be applied at one-third depletion during January through June and at two-thirds depletion over the remainder of the year.Fertigation is an effective method of fertilizing in arid climates. Fertilizer levels in the soil are maintained at constant levels of 35–60 mg/kg throughout the irrigation period. Studies suggest that optimum nitrogen rate for mature Shamouti orange trees is about 170kg/ha/year. Higher nitrogen (N) rates increased yields but decreased external fruit quality by delaying peel color development and increasing peel thickness. However, juice quality, specifically total soluble solids, was not affected by nitrogen rate.A plant exposed to uniform regime of moisture and nutrient flow within rhizosphere zone has to spend much less energy than the growing conditions constantly changing over time. Fertigation, is thus, energy efficient as well. While addressing these concerns, however, the major concern emerges as orchard efficiency vis-a-vis FUE/WUE by adopting variable rate fertilizer application taking into consideration the spatial variability in soil properties in a time domain manner known as automated fertigation.This has led to an increase in both fertilizer use efficiency (FUE) and water use efficiency (WUE).

Optimal Irrigation Scheduling of Garlic (Allium sativum L.) using Allowable Soil Moisture Depletion for Water Scarce Areas of Ethiopia

The main objective of this study was to evaluate the responses of garlic to the irrigation regime (when and how much) to irrigate. The field experiment was conducted at the main station of Debre Zeit Agricultural Research Center in 2016 and 2017. Five treatments for allowable soil moisture depletion levels (ASMDL) of irrigation at 60%, 80%, 100%, 120%, and 140% were used. Application of irrigation water for garlic was scheduled when 30% of the total water available in the soil profile was depleted. Treatments’ were laid out in RCBD experimental design with three replications for each treatment. In the study, it was observed that there was a significant difference in marketable yield and water use efficiency (WUE) between treatments. The maximum marketable bulb yield (7.5 t/ha) and WUE were observed by applying irrigation water at 20% more than the recommended ASMDL and the lowest (4.68 t/ha) was recorded at 40% less than the recommended ASMDL. Reducing the allowable soil moisture depletion level by 40% and also by 20% from the recommended fraction (0.30) has significantly increased the water use efficiency. Generally, from this study it has been observed that irrigating garlic at a shorter frequency enhance yield and water productivity. Therefore, managing the soil moisture content above the allowable depletion level (i.e 60% ASMDL and 80% ASMDL) was better than using the recommended allowable depletion and the other lower levels. Hence, to have a higher yield and maximum water productivity, it was recommended to irrigate garlic frequently.

Effect of Water Regimes and Polyvinyl Alcohol on Faba Bean Yield, Chemical Composition and Water Use Efficiency

Quantifying local crop response to irrigation is important for establishing proper irrigation management approaches.To apply that, a field experiment was carried out to evaluate the effect of three available soil moisture depletion(ASMD) levels, 25 %, 50 %, and 75% applied using solid set sprinkler irrigation system in combination with four concentrations (0.00%, 0.05%, 0.1% and 0.2 %)of poly vinyl alcohol soil conditioner. The combined effect of water regimes and different concentrations of soil conditioner was studied on faba bean (Vicia faba cvGiza 843), The experiment was carried out in the semiarid climate of northeast Farm of El-Ismailia Agricultural Research Station, El-Ismailia Governorate Egypt during two successive seasons(2012/2013 and 2013/2014).Evapotranspiration (ETa), yield productivity of faba bean, water use efficiency and macronutrients uptake were also evaluated. Results showed that the actual seasonal crop evapotranspiration (ETa) for ASMD treatments varied between (1605.36 –2482.45m3 fed-1.) in the first season (2012/2013) and (1439.26 – 2457.01m3 fed-1.) in the second season (2013/2014). There are three options to calculate seasonal ETc for faba bean crop in Ismailia condition. So, it can be use FAO-24RD, PMd or Droogers and Allen (2002)methods. Moreover,obtained data reveal that application of polyvinyl alcohol(PVA)synthetic soil conditioners (with high concentration), decreased available soil moisture depletion (ASMD) in sandy soil and caused a significant increase in faba bean yield, water use efficiency (WUE) and improved the macronutrient uptake by faba bean yield. Finally, the results clearly showed that the significant effect of PVA at (0.1or 0.2 %) concentration was most observed at 50% ASMD.

A study on different micro-irrigation techniques for mitigating water stress of immature rubber (&lt;em&gt;Hevea brasiliensis&lt;/em&gt;) plants

The Intermediate and Dry Zones of Sri Lanka have been targeted in expanding the rubber plantations with a view to expand the extent under planting to achieve national targets in natural rubber production. However, climatic conditions of these regions are suboptimal for growing of rubber. The mid-year dry period in these areas extends from June to September and as a result, plants experience a severe water stress especially in nursery and immature period. Therefore, this study was carried out in the Kilinochchi District, which belongs to the Agro-ecological Zone, DL3 in order to assess the performance of micro-irrigation techniques for immature or young rubber plants. Two micro-irrigation systems; viz. drip and spray jet were tested under three soil moisture depletion levels; 30, 50 and 70% of available soil moisture. Results showed that the growth of immature young rubber plants were highly responsive to moisture depletion levels and micro-irrigated systems. It was found that both drip and spray jet irrigation systems performed well in supplying water at 30% depletion level when compared to the depletion levels of 50 and 70%. Water stress is created by 70% depletion level with decreased chlorophyll content, stomata closure and increase in leaf temperature. Adequate irrigation at 30% depletion level in both systems resulted significant increment of chlorophyll content (p< 0.05). There was significant increment in chlorophyll content in plants which were irrigated with spray jet system when compared to drip system. Plants which were irrigated at 30% depletion level regulated higher stomatal conductance even under higher temperatures during mid-day period.

Determination of Optimal Irrigation Scheduling for Onion (Allium Cepa L.) in Raya Valley, Northern Ethiopia

Irrigation technologies that save water are necessary to assure the economic and environmental sustainability of commercial agriculture. Precision irrigation scheduling is critical to improving irrigation efficiency. A field experiment was conducted to evaluate the responses of onion to irrigation regime (when and how much) and to identify water productivity under optimal irrigation regime. The study was conducted for three non-consecutive years at Mehoni Agricultural Research Center, Raya valley, Ethiopia. Five irrigation scheduling (60% ASMDL, 80% ASMDL, 100% ASMDL (FAO recommended ASMDL), 120% ASMDL and 140% ASMDL were used. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. Bomby Red variety of onion was used for this experiment. Results showed that onion marketable, total bulb yield and water productivity was significantly affected by irrigation scheduling. The highest marketable onion bulb yields of 27.45, 26.92 and 26.76 ton/ha were obtained from treatment 60% ASMDL, 80% ASMDL and 100% ASMDL, respectively. The lowest yield of 24.45 and 24.32 ton/ha was obtained from treatment 120% ASMDL and 140% ASMDL respectively. The highest water productivity (WP) of onion 5.81 kg/m 3 was obtained from treatment of FAO recommended available soil moisture depletion level followed by +20 % FAO recommended ASMDL, while the lowest value of 4.74 kg/m 3 was obtained from treatment -40% or 140% FAO recommended ASMDL. Therefore, based on the current findings, application of irrigation scheduling for onion in study and similar agro - climatic area and soil type application of irrigation at 100% ASMDL or FAO recommended gives highest bulb yield and water productivity. Keywords: ASMDL, Irrigation scheduling, Onion, Water productivity DOI : 10.7176/JNSR/9-20-02 Publication date :October 31 st 2019

Effect of irrigation scheduling at different management allowable deficit by using pan evaporation on wheat yield and water efficiencies at North Delta

Two field experiments were carried out at Sakha farm, Kafr El-Sheikh Governorate during 2016/2017 and 2017/2018 to investigate the effect of irrigation scheduling at different allowable soil moisture depletion (ASMD) levels by using Pan evaporation method (PEM) on wheat yield and water efficiencies at North Delta. Four irrigation treatments; 40, 50, 60, and 70% ASMD denoted as I1, I2, I3 and I4, respectively. The design of the experiment was randomized complete block with three replicates. The obtained results showed that the highest amount of seasonal water applied was recorded under PEM at 60 % ASMD. Meanwhile, the lowest value was recorded with I4 treatment in both seasons. Both of actual water consumptive use and water stored have the same order; I3 > I2 > I1 > I4. The highest water application efficiency values were achieved with I4 treatment. Irrigation treatment (I1) surpassed the other irrigation treatments in increasing the water productivity, productivity of irrigation water, wheat yields and its components as well as grain yield, total seasonal return, net seasonal revenue and benefit cost ratio. Irrigation treatment I1 has superiority in increasing the grain yield by (4.36, 9.86 and 13.18 %) & (1.33, 7.17 and 10.55 %) for I2, I3 and I4, in the 1st and 2nd seasons respectively. Under the conditions of the current study, irrigation treatment I1 (irrigation scheduling by PEM at 40% ASMD) is the proper treatment to obtain the higher production of wheat crop and higher profitability.

Yield and Some Water Relation of wheat (Triticum aestivum L.) Crop as Influenced by Irrigation Regime, Nitrogen Fertilization Rates and Dosses at North Nile Delta.

Two field experiments were carried out at Sakha Agricultural Research Station, Kafr El-Sheikh Governorate, Egypt during the two successive seasons of 2014/2015 and 2015/2016. The objectives of this research were: (i) to study the effect of irrigation regime using tow irrigation levels (40% and 60%) of soil moisture depletion on wheat grain yield; (ii) to evaluate the growth, yield and N use efficiency of wheat as affected by different rates of N fertilization. The experimental used design was split split plot design with three replicates. Irrigation regimes I1 (irrigated at 40% depletion) and I2 irrigated at 60% depletion were assigned in the main plots. Three nitrogen rates i.e. zero, 50, and 75 kg N fed-1 in the sub plots namely N0, N50, and N75 and two doses of nitrogen i.e D1 one time and D2 tow times Results showed that irrigation at 40% depletion significantly increased grain yield by 6.03, 5.5% and straw yield by 7.8, 9.1% compared to irrigation at 60% depletion during the tow growing seasons respectively. The highest grain yield value of 3107.43, 2955.50 kg fed-1 was obtained with I1N75D2 treatment, while the lowest one was 2265.05, 2174.05 kg fed-1 with I2N50D1­ in the 1st and 2nd seasons respectively. Also irrigation at 40% depletion resulted in the higher amount of irrigation water to be 1810, 1920 m3 fed-1 distributed on 5 irrigations while it was 1460, 1600 m3 fed-1 irrigated at 60% depletion distributed on 4 irrigations during the 1st and 2nd seasons respectively. The highest consumptive water use was obtained under irrigation at 40% depletion i.e 38.53, 39.6 cm while the lowest 32.48, 32.58 cm obtained from irrigation at 60% depletion in the 1st and 2nd seasons respectively. Increasing nitrogen rates up to 75 kg N fed-1 (N75) significantly increased grain yield by 234.4%, 119.0% and 218.5%, 111.2 % as compared to control N0; N50 treatments in the 1st and 2nd seasons respectively. Also, increased straw yield by 192.9%, 111.4% and 182.4%, 111.6% as compared to N0; N50 treatments in the 1st and 2nd seasons respectively. Nitrogen use efficiency (NUE) increased with increasing water applied. It was 0, 42.07, 24.23 and 0, 31.74, 17.32 for N0, N50 and N75 on the 1st and 2nd seasons respectively, results showed that increasing the applied N-rate decrease the NUE since the highest value was obtained with N50 and the lowest one obtained with N75. The highest water productivity (WP) of 2.20, 2.4 kg m-3 was obtained with I2N75D2 treatment during 1st and 2nd seasons respectively. Therefore, it could be recommended that irrigate wheat at 60% depletion in north Nile Delta soils to save water of about 320 m3

Optimal Soil Moisture Depletion Levels for the Production of Vernonia (Vernonia galamensis L.) and it’s Effect on Growth, Yield and Yield Components

The field experiment was carried out at Wondo Genet Agricultural Research Center 07°03’19’’ to 07°04’00’’ N latitude and 38°30’08’’ to 38°31’02’ E longitude during 2015/16 dry season. The experiments were arranged in a randomized complete block design with three replications. Seven soil moisture depletion levels (30, 40, 50, 60, 70, 80 and 100% of the total available water of the soil) were used. The result indicated that different soil moisture depletion levels had very highly significant (p<0.001) effect on days to flowering, days to seed set, days to maturity, plant height, number of branches per plant, number of capsules per plant, thousand seed weight and seed yield. It was also affected oil yield highly significantly (p<0.01). Moreover, different soil moisture depletion levels significantly (p<0.05) influenced water use efficiency. However, different soil moisture depletion levels showed no significant difference in the oil content of Vernonia. Vernonia grown under 100% SMDL took a shorter number of days to 50% flowering, days to seed setting and days to maturity. On the other hand, 30% SMDL took the longest days to flowering, seed setting and days to maturity. The maximum plant height, number of branches per plant and number of capsule per plant were 162.7 cm, 150 and 196.8 at 30% SMDL, respectively. The highest seed yield (2213 kg ha-1) and oil yield (711.8 kg ha-1) were obtained at 60% soil moisture depletion level. However, the highest water use efficiency based on oil yield (0.15 kg/m3) was obtained at 100% SMDL irrigation is set when soil moisture content touches PWP. Thus, the optimal seed yield, oil yield and WUE could be achieved when 493.4 mm seasonal net irrigation depth of water applied with scheduling at 60% SMDL for the production of Vernonia at Wondo Genet and similar agro-ecological areas.