َA. H. Jalali; H.R. Salemi
Abstract
Introduction: In recent years, canola cultivation in Iran has been considered as oil production, and in 2014-2015, it has been allocated to 7.7% of the cultivation area of industrial products of the country. The yield of canola oil and seeds depends on the availability of sufficient water resources during ...
Read More
Introduction: In recent years, canola cultivation in Iran has been considered as oil production, and in 2014-2015, it has been allocated to 7.7% of the cultivation area of industrial products of the country. The yield of canola oil and seeds depends on the availability of sufficient water resources during the growth period. In the Mediterranean, with the cultivation of canola autumn, the high- temperature occurs in the stages of formation and growth of seeds in the spring can increase the water requirement of this plant and irrigation management at this time is important in increasing plant yield. Due to the weather conditions of each area, type of variety and soil conditions may vary the need for canola. In one study in Hamedan water use efficiency of canola in two ways drip and furrow irrigation were calculated as 1.09 and 0.63 kg m-3, respectively. The present study was conducted with the purpose of evaluating the net water requirement of canola plant in different cities of Isfahan province into different climatic zones and considering the phonological stages. Materials and Methods: In order to estimate the net water requirement of canola under two different climates (arid-cold winter with temperatures above freezing point - hot summer A-C-W) and (Semi-arid-cold winter with a temperature equal to or less than zero-hot summer SA-K-W) in Isfahan province, a research was conducted in 2014-2015 using a completely randomized, unbalanced design. The study was carried out in different cities of Isfahan province, which have canola cultivation. The required statistical information was obtained from 28 stations of synoptic and climatologic meteorology in Isfahan province and some neighboring provinces. Soil data was used to calculate the soil evaporation coefficient (Ke), which describes the evaporation component in the trait (ETc). In order to calculate the soil properties, in addition to the sampling of existing fields, a database of 1600 soil profiles in the Soil and Water Research Department of Isfahan province was also used. The plant growth stages were considered based on FAO’s 56 irrigation and drainage journal. For analyzing data in each climate, a completely randomized, unbalanced design (with inequality repeat) was used, and the meanings were compared with Duncan’s multiple range test (at 5% level). Results and Discussion: There was a significant difference (α=1%) between the different cities in terms of total water consumption and the net water requirement of different phenological growth stages. In the SA-K-W climate, the net water requirement for each hectare of canola cultivated in the cities of Fereydoun Shahr, Friedan, Golpayegan, Khansari, Semirom, Tiran and Karvan, Shahreza, Chadegan, Dehaghan, and Boein va Mian Dasht was 3936, 4069, 4258, 4011, 3991, 4147, 3964, 3961, 4035 and 4055 m-3, respectively. In the SA-K-W climate (with ten cities), the net water requirement of canola was estimated at 4,000 m-3 ha-1. The difference between the highest and the least water requirement in this climate were 322 m-3 ha-1 and related to cities of Frieden and Fereydoun City, respectively. In the climate of A-C-W (12 cities), canola net water requirement was 892 m-3 ha-1 more than the net water requirement of this crop in the SA-K-W climate. On average, the initial, developmental, and (middle and final) net water requirements of the canola in the A-C-W climate were 540, 2150, and 2200 m-3 ha-1, respectively. The net irrigation requirement estimated for each ha-1 of canola cultivation in Isfahan, Ardestan, Khomeini Shahr, Falavarjan, Kashan, Lenjanat, Naein, Najaf Abad, Natanz, Shahin Shahr, Mobarakeh, and Borkhar cities was 4747. 4807. 4797, 5,105, 4885, 4908, 4750, 4785, 4974, 4971, 4879 and 5097 m-3, respectively. Conclusion: Based on the results of the 10 cities in the SA-K-W climate, canola production per hectare requires an average of 4,000 cubic meters of net water per hectare. In the A-C-W climate of 12 cities, the average net water requirement per hectare was 4892 m-3. The difference in water requirement between this climate and the climate of SA-K-W was related to the middle and late stages of canola growth.
Hamid Reza Salemi; Ali Reza Tavakoli
Abstract
Introduction: Water crisis as a majorlimitation factor for agriculture, like other arid and semiarid regions exists in Isfahan province which is located in the central part of the Zayandehrud River Basin (ZRB). Rice appears to be the far-most profitable crop but at the same time it has a major impact ...
Read More
Introduction: Water crisis as a majorlimitation factor for agriculture, like other arid and semiarid regions exists in Isfahan province which is located in the central part of the Zayandehrud River Basin (ZRB). Rice appears to be the far-most profitable crop but at the same time it has a major impact on basin scale water resources, especially affecting downstream farmers. In the study area (ShahidFozveh Research Station), the water resources for agricultural production face heightened competition from other sectors like industry and domestic use. This necessitates considering different crops, altered agricultural systems and innovative methods that can reduce the water requirements for the irrigation of rice. The Alternative Wetting and Drying (AWD) seems to be an effective method reducing water use for rice crops and possibly save the water for downstream users. There have been no qualitative evaluations of rice production under deficit irrigation practices in Isfahan area. This study sought to determine, under study area conditions, the quantities of water irrigation used with AWD practices, the resulting water productivity (WP) and the effects of alternative irrigation management on yield, quality indices and rice production performance.
Materials and Methods: The ZRB (41,500 km2) is a closed basin with no outlet to the sea. The research was conducted in the Qahderijan region of Isfahan province, which is located in the central part of the ZRB. The ShahidFozveh Agricultural Research Station (32°, 36’ N, 51°, 36’ E) is located at the altitude of 1612 m above the sea level. In order to improve WP and illustration of the impact of various levels of flooding depth on grain yield and quality indices at rice production, a field experiment (3000 m2) was conducted at ShahidFozveh Research Station for 2 years arranged in a split plot design with three replications. It will be necessary to use different scenario of water flooding depth management to achieve the highest irrigation application efficiency and WP. The treatments included: three levels of irrigation managements I1: permanentflooding under 3.5 cm water during growth period, I2: permanent flooding under2.2cm water during growth period and I3: 0-1.5cm. (AWD) were considered as main plots and eight advanced rice cultivars (Geredehmahali, Zayandeh-rud, Sazandegi , Hasani, 67-97, 67-113, 67-47 and 67-72) as sub plots. The treatments were compared based on grain yield and quality indices for irrigation management and rice varieties including: amylose content (AC), Gelatinization temperature (GT) and gel consistency (GC). Production (grain yield), quality indices, the consumption water, WP and cultivars reactions to different irrigation management were evaluated in different treatments. The soil of the experimental area, according to USDA Soil Taxonomy 1994 is of FINE CLAYEY. At the soil depth of 1m, soil salinity (6.2 dS.m-1), water salinity (3.9 dS.m-1), and soil moisture at saturated capacity (48 Vol. %) at the field site were measured or experimentally obtained in the Isfahan Soil and Water Laboratory. The results were subjected to an ANOVA to analyze the effects of the treatments and their interactions using PROC GLM (SAS 9.1, SAS institute Ltd., USA). Duncan’s multiple range tests at 0.05 probability level was used for paired mean comparison.
Results and Discussion: Results showed that water flooding depth treatments had significant effect on gel consistency, geletination degree and WP (P0.01). Significant differences (P0.01) were noticed in Gelenation degree, gel consistency, grain yield, WP among the cultivars. Also cultivars have significant effect (P0.05) on amylose contents. The highest magnitude of WP was calculated 0.91kg.m-3for (I3) followed by Zayandehrud, 67-113 and Sazandegi with 0.86 and 0.85, respectively. Maximum WP obtained from AWD irrigation management and Zayandehrud rice variety, its amount was 9.1kg.mm-1. At this treatment with 33.4 percent reduction of irrigation water, have resulted only 11.1 percent decreased of paddy grain yield. Results showed that it is not necessary to maintain the rice field submerged in whole growth period. Considering the importance of water flooding depth optimization as the main scope in arid and semi-arid lands of Iran, (I3) is recommended.
Conclusion: During the two years of conduction of an experiment in ZRB with clay texture and mild saline water with the three (3) irrigation treatments imposed on the rice crop. The highest WP was achieved for (I3) followed by Zayandehrud, 67-113 and Sazandegi, respectively. It was found that the AWD irrigation management, despite its lower yield than other irrigation treatments, increased water productivity. Thus, this treatment is desirable therefore highly recommended for agricultural rice production in arid region.
