Investigation of the Response of onion (Allium Cepa L.) to continuous deficit irrigation as smart approaches to crop irrigation under Mediterranean conditions (original) (raw)
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Irrigation Water Management of Horticultural Crops
HortScience, 2003
WP by increasing yield and/or reducing ET always results in net savings, thus reducing agricultural water requirements. This is a key point in assessing the opportunities for true water savings in horticultural crop cultivation and will be addressed in detail later in this paper. Water productivity in irrigated agriculture varies widely and depends on many biophysical and management factors. Because variations in ET among crops are within an order of magnitude apart, by far the most important factor infl uencing WP is the economic value of the product. Horticultural products are usually high value and thus WP normally exceeds that of fi eld and row (agronomic) crops. For example, using current values for yield and ET characteristic of California agriculture, the WP of corn is about 0.20 /m3,comparedto0.70/m 3 , compared to 0.70 /m3,comparedto0.70/m 3 for almond, 5.00 /m3forstrawberry,andevenmoreforgreenhouseandornamentalcrops.AnextremeexampleofthisoccurswithvegetablecropsgrownunderplasticinsoutheastSpainduringtheoff−season.ThecombinationofhighmarketpricesandlowETleadstoaWPofabout10/m 3 for strawberry, and even more for greenhouse and ornamental crops. An extreme example of this occurs with vegetable crops grown under plastic in southeast Spain during the off-season. The combination of high market prices and low ET leads to a WP of about 10 /m3forstrawberry,andevenmoreforgreenhouseandornamentalcrops.AnextremeexampleofthisoccurswithvegetablecropsgrownunderplasticinsoutheastSpainduringtheoff−season.ThecombinationofhighmarketpricesandlowETleadstoaWPofabout10/m 3. While impressive, even this value cannot compete with that of industrial and urban uses. Nevertheless, it helps explain the trend of shifting irrigated acreage from low value fi eld and row crops to horticultural crops in many water-scarce areas of the US, a trend that will probably increase worldwide (National Research Council, 1996). Indeed, the WP of an irrigation district in Southern Spain increased over a four year period as the proportion of horticultural crops increased (I. Lorite, L. Mateos, and E. Fereres, unpublished data). This paper describes the evolution of water use as related to productivity with an emphasis on the U.S. experience, analyzes how irrigation systems and management have evolved since the early 1900s, and explores the challenges and opportunities for water conservation in horticulture. Because of the broad scope of the subject and limited space, the paper focuses primarily on tree crops although many principles are applicable to all horticultural crops.
International journal of natural resource ecology and management, 2022
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/m 3) 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/m 3 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/m 3) was attained at 80 percent ASMDL, whereas the minimum efficiency of water use (5.29 kg/m 3) 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.
Agricultural Water Management, 2008
The amount of water used by any crop largely depends on the extent to which the soil water depletion from the root zone is being recharged by appropriate depth of irrigation. To test this hypothesis a field study was carried out in November-March of 2002-2003 and 2003-2004 on a sandy loam (Aeric haplaquept) to quantify the effect of depth of irrigation applied through micro-sprinklers on onion (Allium cepa L.) bulb yield (BY) and water use patterns. Seven irrigation treatments consisted of six amounts of sprinkler applied water relative to compensate crop (K c) and pan (K p) coefficient-based predicted evapotranspiration loss from crop field (ET p) (i) 160% of ET p (1.6ET p); (ii) 1.4ET p ; (iii) 1.2ET p ; (iv) 1.0ET p ; (v) 0.8ET p ; (vi) 0.6ET p ; (vii) 40 mm of surface applied water whenever cumulative pan evaporation equals to 33 mm. Water use efficiency (WUE), net evapotranspiration efficiency (WUE ET) and irrigation water use efficiency (WUE I) were computed. Marginal water use efficiency (MWUE) and elasticity of water productivity (EWP) of onion were calculated using the relationship between BY and measured actual evapotranspiration (ET c). Yield increased with increasing sprinkler-applied water from 0.6 to 1.4ET p. Relative to the yield obtained at 0.6ET p , yield at 1.0ET p increased by 23-25% while at 1.4ET p it was only 3-9% greater than that at 1.0ET p. In contrast, yield at 1.6ET p was 9-12% less than that at 1.4ET p. Maximum WUE (7.21 kg m À3) and WUE ET (13.87 kg m À3) were obtained under 1.0ET p. However, the highest WUE I (3.83 kg m À3) was obtained with 1.2ET p. The ET c associated with the highest WUE was 20% less than that required to obtain the highest yields. This study confirmed that critical levels of ET c needed to obtain maximum BYs, or WUE, could be obtained more precisely from the knowledge of MWUE and EWP.
Principles of Irrigation Management for Vegetables
Vegetable Growing [Working Title], 2021
Vegetables have a very high percentage of water content. Some of the vegetables, such as cucumber, tomato, lettuce, zucchini, and celery contain over ninety-five percent of water. As a result of the high-water content in the cells, they are extremely vulnerable plants to water stress and drought conditions. Their yield and quality are affected rapidly when subjected to drought. Therefore, irrigation is essential to the production of most vegetables in order to have an adequate yield with high quality. However, over-irrigating can inhibit germination and root development, decrease the vegetable quality and post-harvest life of the crop. Determination of suitable irrigation systems and scheduling to apply proper amount of water at the correct time is crucial for achieving the optimum benefits from irrigation. This determination requires understanding of the water demand of the vegetable, soil characteristics, and climate factors. All these factors have major impact for the success and...
Sustainable Water Resources Management, 2018
Optimizing irrigation water requirement is necessary to improve productivity of irrigated agriculture. Hence, adapting the knowledge of irrigation scheduling for specific crop and location is important. Field experiment was then conducted in Raya Alamata district of Tigray, Ethiopia to investigate the impact of different irrigation water levels on yield and irrigation water use efficiency (IWUE) of tomato. Eight treatments (50, 35, 25% above estimated crop water requirement (CWR), estimated CWR, 25, 35, 50% below the estimated CWR and farmers practice) were arranged in randomized complete block design under three replications. Tomato water requirement was estimated using CROPWAT 8 software and it was estimated to be 500 mm throughout the base period. The result indicates significant difference between marketable yield (MY), total yield (TY) and IWUE of tomato by the level of irrigation. The application of estimated CWR of tomato gave higher MY (36.37 ton/ha) and TY (38.58 ton/ha). Unmarketable fruit yield of tomato was unaffected by level of irrigation. Farmers' practice gave considerable MY (36.32 ton/ha). But, the depth of water applied by farmers throughout the growing season was 561 mm which was 12.2% above the estimated CWR. The yield obtained per unit of applied water (IWUE) ranges from 0.357 to 0.876 kg/m 3 for the different irrigation water levels. This shows that IWUE increases with decreasing depth of water application. In conclusion, deficit irrigation practice could be successful in saving irrigation water up to 35% of tomato CWR without significant reduction in fruit yield of tomato in regions where water is a limiting factor for vegetable production.
Evaluation of Water Productivity under Furrow Irrigation for Onion (Allium cepa L.) Crop
Advances in Agriculture
Irrigation water management practices are the main strategies to improve water productivity. This research work was focused to study the performance of alternate and paired row furrow irrigation systems at three levels of irrigation (100%, 75%, and 50% of crop evapotranspiration) using different water productivity indicators for onion crops. The experiment had six treatments and replicated three times to evaluate the analysis of variance in SAS software. Water productivity indicators like crop water use efficiency, field water use efficiency, and field water expense efficiency were determined through bulb yield and water which were used by the crop. The crop yield was expressed as the total yield of onion bulbs, and crop water use was expressed as crop evapotranspiration (ETc), gross depth of irrigation, and water expense. The estimated maximum values of crop water use efficiency, field water use efficiency, and field water expense efficiency were 11.941, 16.152, and 9.361 kg m−3, r...
…, 2011
ADDITIONAL INDEX WORDS. crop water requirements, evapotranspiration, irrigation methods SUMMARY. Irrigation is a vital component of the world agriculture. It is practiced worldwide on %270 million hectares and it consents to produce 40% of our total food. Agricultural water consumption accounts for 70% of total freshwater use. The competition for this precious resource is increasing tremendously. Therefore, it is becoming critically important to optimize agricultural water use efficiency (WUE) defined as the ratio of crop yield over the applied water. This requires a shift from maximizing productivity per unit of land area to maximizing productivity per unit of water consumed. To maximize WUE it is necessary to conserve water and to promote maximal crop growth. The former requires minimizing losses through runoff, seepage, evaporation, and transpiration by weeds. The latter objective may be accomplished by planting high-yielding crops/cultivars well adapted to local soil and climatic conditions. Optimizing growing conditions by proper timing of planting and harvesting, tillage, fertilization, and pest control also contribute to improve crop growth. Most of these techniques refer to proven technology, whose implementation and/or fine-tuning in current farming systems may tremendously improve water management efficiency. In this paper, after discussing the importance of irrigation in agriculture, we will introduce basic concepts that define crop WUE and will finally review the means to improve irrigation efficiency in field vegetable crop production.