Determination of the Best Compost Tea Concentration as a Potential Method to Maximize the Growth of Two Artemisia and Salsola Species in Dryland Region

Little information is available on the effects of applying compost tea to species in dry regions. Compost from agricultural waste can promote drought resistance in plants and increase their growth by improving soil structure and providing nutrients and enhancing the capacity of the soil to store moisture. In order to examine these effects, compost tea was tested on two species growing in dry regions (mountain sagebrush, Artemisia aucheri and Salsola, Salsola tomentosa) at 5 various concentrations; 0, 10, 20, 30 and 40 (m3/ha). This research was conducted as a field study at Neiriz (29o 36''N, 53o 59''E, altitude 1776 m) in Fars province, Iran, during the 2009-2010 growth season. The experiment was factorial, based on a randomized complete block design with 10 treatments and 3 replications. The results showed that compost application increased plant height (25.1%), crown diameter (10.5%), and fresh (7.0%) and dry (5.9%) weights up to a concentration of 40 m3/ha, compared with the control (without compost). It was also found that bulk density, electrical conductivity and soil organic matter all increased after the application of compost. In some cases (e.g. crown diameter and fresh and dry weight), a high concentration of compost had negative effects, which might have been due to osmotic potential. Salsola responded better to compost application than Artemisia. Overall, 30 m3/ha was the most effective concentration of compost tea to stimulate growth increase of Salsola and Artemisia in dryland conditions.