بررسي امكان توليد علوفه در دو توده كوشيا .(Bassia scoparia L) با كاهش مصرف آب در شرايط شور

The possibility of forage production of two kochia accessions by reducing water application under saline conditions

سابقه و هدف: در تمامي مناطق خشك و نيمه خشك، آبياري براي توليد محصولات زراعي ضروري است، همچنين شور شدن خاك نيز غيرقابل اجتناب است. بنابراين براي تضمين توليد در اين مناطق كاشت گونه هايي از محصولات با آستانه تحمل بالا و كاهش كم محصول در شرايط كم آب و شور ضروري است. كشاورزي و دامپروري در مناطق خشك و نيمه خشك همواره همراه هم بوده است، بنابراين تهيه علوفه براي دام ها يكي از دغدغه هاي اصلي كشاورزان اين مناطق است. كوشيا ((Bassia scoparia (syn. Kochia scoparia) گياهي است يك ساله كه مقاومت به شوري و خشكي بالايي دارد. اين گياه قادر است با استقرار سريع خود در خاك هاي شور، علاوه بر ايجاد يك پوشش محافظتي يك ساله به عنوان يك علوفه جايگزين به ويژه در مناطق خشك و نيمه خشك معرفي شود. بنابراين هدف از اين مطالعه ارزيابي ميزان تحمل به خشكي كوشيا در شرايط آبياري با آب شور در مراحل مختلف رشدي با تأكيد بر خصوصيات علوفه اي كوشيا بود

Background and objectives: In all arid and semi-arid area irrigation is necessary for crop production; salinization of soil is also unavoidable. Therefore, for sustainable crop production in such areas, growing crop species with higher threshold and lower yield reduction under saline and water shortage conditions is needed. Agriculture and animal husbandry are integrated in arid and semi-arid regions. Therefore, providing of forage for livestock in these areas is one of the main concerns of farmers. Kochia (Kochia scoparia L. syn Bassia scoparia L.) is an annual plant with high tolerance to salt and drought stress. It is capable to rapid established in saline soils, and is a ground cover plant that can introduced as an alternative fodder, in arid and semi-arid areas. Therefore, the aim of this study was to evaluate the drought tolerance of kochia in irrigation with saline water at different growth stages with emphasis on the forage characteristics. Materials and methods: Experiment was conducted as split-plot based on randomized complete block design with three replications at the salinity research station of center of excellence for special crops of Ferdowsi University of Mashhad, Iran in 2008. In order to stimulation of drought stress at first and final growth stages drought stress was applied for four weeks. Three levels of drought stress (control, no irrigation in vegetative stage (recovery treatment) and no irrigation at reproductive stage for one month (stress treatments), and two kochia accessions (Birjand and Borujerd) were arranged as main and sub plots, respectively. Plants were irrigated with underground water with electrical conductivity (EC) of 5.2 dS m-1. Forage harvesting was carried out after the third-stress treatment, in full flowering stage. Conclusion: Four weeks irrigation cuts at vegetative and reproductive stages did not affect forage yield of kochia, and showed the high capability to recover the adverse effects of drought stress in vegetative growth stage. Generally, kochia has morphological features for introduce as a forage crop in saline and arid areas. In addition, the physiological mechanisms of drought and salt tolerance of kochia may introduce it as a candidate forage species for cultivation and to help feed the livestock in areas where salinity and drought stress is dominant