Effect of Irrigation on Yield and Green Growth Period in Nine Range Plants in Urmia

To study the effect of irrigation on yield and green growth period in nine range species in climatic conditions of Urmia , an experiment was conducted as split plots in a randomized complete block design with three replications at the Agricultural Research Station, Urmia University. Main plots were consisted of three irrigation regimes: non, few and several irrigations. Nine grass species of:
Arrhenatherum elatius , Bromus inermis , Festuca pratensis , Festuca arundinacea , Agropyron trichophorum , Secale montanum , Bromus tomentellus , Agropyron desertorum and Elymus junceus.
Effect of the plant treatments on yield as well as green growth during three growing seasons were evaluated. Analysis of variance along with mean comparison between treatments indicated that there were significant differences among irrigation regimes for plant species. There was also considerable variation observed among species in dry matter yield. Maximum dry matter yield with 7482 kg/ha belonged to Arrhenatherum elatius in several times irrigation regime. Dry matter yield in the above mentioned plant was reduced by 25% in natural rainfall condition as compared with the several times
irrigation regime. Minimum dry matter yield was 135 kg/ha obtained from Festuca pratensis in natural rainfall conditions, however, at several times irrigation regime dry matter yield increased by 85%. The green growth period did not follow any particular trend in irrigated plots, but the greennes period in Secale montanum was more than that in the other plants in non irrigated plots, while it's dry matter yield decreased in irrigation conditions. In conclusion irrigation and selection for high mean productivity in range plants can present a beneficial effect on yield in areas where rainfall is not adequate