Olive Irrigation Management Project Setting the Scene

Transcription

1 live Irrigation Management Project Setting the Scene V. Nangia, and M. Karrou live Irrigation Management Project Setting the scene.. 7 th International Conf. on Water Resources in the Mediterranean Basin, ct 1-12, Marrakech, Morocco V. Nangia 1*, M. Karrou 2 1 International Center for Agricultural Research in the Dry Areas (ICARDA), Amman, Jordan * v.nangia@cgiar.org 2 ICARDA, Rabat, Morocco Abstract - The key success factors of the olive oil market are the enhancement and stabilization of olive yields, improvement of olive oil quality and reduction of production costs. There is great potential for water saving in olive production in Morocco and Syria. The main purpose of this four year (21-214) study is to enhance crop yields of smallholder olive farmers in two Mediterranean countries - Morocco and Syria, through the optimization of water management practices applied to olive cultivation. Due to the sufficiency of rainfall in Syria for growing olives, the study investigates the effect of supplemental irrigation in increasing and stabilizing yield, whereas in Morocco the low rainfall allows only irrigated olive cultivation and so the study investigates the effects of deficit irrigation in reducing water consumption without adversely affecting the olive yield. Results indicate that adding 23 mm (@ 1% of crop water requirement) supplemental irrigation led to as much as 175% increase in olive yields in Syria, and in Morocco, adding water at 7% of ETc led to 63-77% saving in water compared to flood irrigation along with 13-43% increase in yield. olive oil quality and reduction of production costs. The main purpose of this four year (21-214) study is to enhance crop yields of smallholder olive farmers in two Mediterranean countries - Morocco and Syria, through the optimization of water management practices applied to olive cultivation. Improved and more stable olive yields are going to lead to improved earnings and livelihoods for the targeted smallholder farmers. The project objective is achieved through the demonstration and dissemination of sustainable irrigation technologies, water management practices and effective irrigation techniques. Pilot demonstration fields were set up in each country (Tessaout research stations near Marrakesh, Morocco and Daraa research stations and farmer s field in Syria, fig. 1) in predominantly olivegrowing areas with diverse soil and climatic conditions, where rainfed or traditional irrigation methods now prevail. The study is transferring best practices and know-how to farmers on irrigation, fertilization and pest control through the management of the pilot demonstration fields and systematic training sessions. Secondary beneficiaries are local researchers and extension officers who benefit from intensive training. Keywords - Drip irrigation, deficit irrigation, Morocco, supplemental irrigation, Syria, water productivity 1. Introduction live has been cultivated since the beginning of historical times in its native Asia Minor. Its cultivation spread very early to most of the Mediterranean countries and this is still the prime area of production since this crop requires very warm average temperatures, dry climates and does not tolerate cold climatic conditions. The key success factors of the olive oil market are the enhancement and stabilization of olive yields, improvement of Figure 1: Location of study sites in Morocco and Syria Syria 2. Materials and methods 1

2 In Syria, since the available rainfall of 3-4 mm in olive growing regions is sufficient for rainfed production, the study investigates adoption of supplemental drip irrigation to substantially increase the olive productivity. There are two sites where research on supplemental irrigation is carried out Al Ash ari farmer s field and a research station both located in Dara a Province. Another site was initially selected and characterized in Sarbaya, near Aleppo (fig. 1), but due to civil unrest and poor security in the area, the research at this site had to be discontinued after July, 211. water requirement, rainfed treatment (control). Trees are on average 3 years old and are spaced at 8 x 8 m distance (fig 3). Drip, 8 drippers/tree for the 1% CWR treatment and 4 drippers/tree for 5% CWR treatment, with a discharge of 16 L/hr/dripper are installed where the irrigation time for the 1% and 5% CWR treatment is equal. Fertilizer application is the same as at the farmer s field. Sorani cv. and Jluott cv. of olive was grown at this site Al Asha'ari Farmer's Field Site The site belongs to a private farmer from Daraa countryside. The average rainfall here is 324 mm. Experiment here includes three water treatments: irrigation to 1% of CWR (crop water requirement), irrigation to 5% of CWR, and rainfed treatment (control). The trees are on-average 46 years old and are spaced at 1 m x 1 m distance (fig. 2). Drip irrigation systems are at 8 drippers/tree for the 1% of CWR treatment and at 4 drippers/tree for the 5% of CWR treatment, with a discharge of 16 L/hr./dripper, where the irrigation time for the two treatments is equal. Fertigation operation is performed using a Dosatron-type fertilizer injector. Two fertilizer management practices were performed in February, 212 and all recommended amounts of phosphorus and potassium (3/kg/ha) fertilizers were added. For nitrogen, 5% of the total amount (3/kg/ha) was added before cultivation, while second half was added by applying fertigation during the season. As for soluble fertilizers (N, P, K), elements, an amount of 1/kg/ha was added during the season; calculation of the amounts of fertilizers depended on soil analyses. Sorani cv. of olive was grown at this site. Figure 3: Experimental design agricultural research station, Daraa, Syria Morocco Two irrigation methods were applied, drip irrigation with two water regimes and flood irrigation or traditional system used by most of the farmers. The planting density of the orchard was 28 trees ha- 1 in the case of flood treatment with a row spacing of 8 m x 6 m and 156 trees ha -1 for drip irrigation treatment with 8 m x 8 m row spacing. In both systems, olive trees had the same age. 1% 5% Rainfed Frame Figure 2: Experimental design Al Asha'ari farmer's field in Daraa Province, Syria. Saada agricultural research station, Marrakech, Morocco Jillin Agricultural Research Station site Jillin agricultural research station belongs to the General Commission for Scientific Agricultural Research (GCSAR). It is located 25 km north of Dara'a City; with an annual rainfall average of 4 mm. Experiment includes three water treatments: irrigation to 1% of CWR, irrigation to 5% of crop 2

3 Water productivity (kg/m3 ET) Water applied (rainfall + irrigation, mm) il yield (kg/ha) Yield (kg/ha) Tessaout pilot plot design, Marrakech, Morocco Figure 4: Experimental design Drip irrigation and traditional irrigation systems are used in two adjacent plots. A randomized complete block design (RCBD) is used with three replications per irrigation regime in the case of drip irrigation system (fig. 4). The drip irrigation plot had an area of 1 ha and the traditional irrigation plot had an area of.5 ha. The drip irrigation experimental plot included 6 subplots (two irrigation regimes x three replicates). The two irrigation regimes under drip irrigation systems are: 1% of crop evapotranspiration (ETc) and 7% of ETc. Each replicate included 1 trees. Deep tillage was conducted on 13 January, 211 at 6 cm depth and 1 meter from the trunk. The ETc was calculated following the equation: ETc = ETo x Kc x Ke / Ne where ETo is the reference evapotranspiration (Penman Monteith) and Kc is the crop coefficient for olive tree, Kr is the corrector coefficient and Ne is the efficiency of irrigation network Syria 3. Results and discussion During 212 growing season, applying deficit supplemental irrigation at Daraa experiment station at 5% ETc (353 mm rainfall mm irrigation) compared to rainfed plantation, fruit yield increased by 2,46 (33%) to 3,9 (96%) kg/ha (fig. 5). Yield of Sorani cv. was always higher than Jlout cv. at all locations. The water productivity (WP) ranged between 1.1 and 2.1 kg/m 3 ET. There was a further increase of 1,25 (13%) to 2,3 (25%) kg/ha by switching from 5% ETc to 1% ETc. The lowest WP was found for rainfed Sorani cv. at farmer s field (not shown here) and highest for rainfed Sorani cv. at experimental station in Daraa, but yields were always higher for irrigated olives plantations compared to rainfed proving that there is a loss of yield if we do not irrigate. In terms of percentage oil extracted from fruit, Sorani cv. grown under 5% ETc treatment produced highest values (24%). Similar results were found during 211 growing season (not shown here) yields increased by as much as 113% (4,375 kg/ha vs. 9,36 kg/ha) when 115 mm of irrigation was applied (in addition to 316 mm rainfall) by drip. A further increase of 2,652 kg/ha (28%) was achieved by applying additional 115 mm of irrigation (1% ETc) in addition to the rainfall Figure 5: Comparison of 212 growing season olive fruit and oil yield, water applied and water productivity between rainfed and drip irrigation (at 1% and 5% ETc) treatments for Sorani cv. and Jlout cv. at experiment station in Daraa Province, Syria Morocco % ETc 5% ETc Rainfed Sorani cv. Jlout cv. In Morocco, the rainfall in olive growing regions is low (2-25 mm) and insufficient to grow olives 769 1% ETc 5% ETc Rainfed % ETc 5% ETc Rainfed % ETc 5% ETc Rainfed 3

4 Water applied (mm) il yield (kg/ha) live yield (kg/ha) Water productivity (kg/m3 ET) using just the rainwater. So, farmers are compelled to practice irrigated olive plantations, mostly using the flood method. ur research compares traditional flood irrigation method with drip irrigation applied at full and regulated deficit level. ur results indicate that by adopting improved irrigation methods, there was a gain in yield of fruit and oil, and water productivity increased significantly, thus, saving water and increasing farmers' income. There was a declining trend with total water applied for all the four parameters. The linear trend was found significant (P<.5) for oil WP % ETc 7% ETc Traditional % ETc 7% ETc Traditional % ETc 7% ETc Traditional Figure 6: Comparison of 211 growing season olive fruit and oil yield, water applied and water productivity between flood and drip irrigation (at 1% and 7% ETc) treatments at Tessaout experiment station in Marrakesh, Morocco. During 211 growing season (a relatively wetter than normal year - 33mm) at experiment site in Marrakesh, by switching from traditional flood irrigation to drip irrigation, there was a saving of 66% of water (6 mm vs. 23 mm), 27% increase in olive fruit yield, 76% increase in water productivity (.19 kg/m 3 vs..78 kg/m 3 ) and 31% increase in oil yield (fig. 6). Another 11% saving of water was possible by applying deficit drip irrigation at 7% of ETc level - yield was 13% higher than traditional irrigation method, water productivity was 8% higher and oil yield was 25% higher. Whereas, 212 growing season received less than normal rainfall (14 mm) and so the water requirement of olive trees, in addition to the rainfall, was higher than the previous year (not shown here). Traditional flood irrigation method consumed 1,61 mm of irrigation water and produced 4,53 kg/ha olive fruit yield at a WP of.43 kg/m 3 ET. Switching to regulated drip irrigation reduced the water usage by 412 mm (39%) for 1% ETc treatment along with an increase of 3,4 kg/ha of yield (4%), and 7% ETc treatment further saved 157 mm water (24%) and further increased yield by 19 kg/ha (2.5%) Statistical analysis % ETc 7% ETc Traditional Using the three and higher factor interaction of year, location, irrigation and cultivar as experimental errors, their main effects and two factor interactions were evaluated using the restricted maximum likelihood method for analysis of unbalanced data. The two factor interactions when found insignificant (P>.5) were also merged into experimental errors. The effects and interactions that were found statistically significant (P <.5) included: irrigation treatments and cultivars for yield and oil, and their interaction for oil. For yield and oil waterproductivities, cultivar differences were significant. 4

5 4. Conclusions The results from research suggest that applying small amount of water by drip irrigation, in addition to rainfall, can be beneficial in two ways it helps increase the yields of fruits as well as oil, and helps stabilize the yields. Acknowledgements The study was presented by the International lives Council (IC) to the Common Fund for Commodities (CFC) for funding and was drawn up at the IC Executive Secretariat in cooperation with the Instituto de Agricultura Sostenible (IAS-CSIC), Spain, and the Instituto per i Sistemi Agricoli e Forestali del Mediterraneo (CNR-ISAFoM), Italy. CFC is an intergovernmental financial institution established within the framework of the United Nations, headquartered in Amsterdam, the Netherlands. 5