Effect of plant density and organic fertilizers on yield and precipitation efficiency index of Bakhtiari savory under dryland farming conditions of Damavand region

The present study was carried out to evaluate yield and precipitation efficiency index of Bakhtiari savory (Satureja bachtiarica Bunge.) influenced by organic fertilizers and different plant densities under dry land farming conditions. The experiment was conducted as a split plot based on a randomized complete block design with three replications at Homand rangeland research station of Damavand, in 2018 and 2019. The main factor was organic fertilizer in three levels, including cattle manure (30 t. ha-1), enriched wheat straw (10 t. ha-1), and control. The sub plots included three levels of plant densities (26666, 40000, and 80000 plant ha-1). The amount of effective rainfall in the first and second years was 278 and 390 mm, respectively. The results showed that the interaction of year and organic fertilizer as well as year and plant density led to a significant increase in dry weight yield and precipitation efficiency index. The maximum dry weight yield was 385 kg. ha-1 in the second year and cattle manure treatment. The highest precipitation efficiency index with 0.986 kg.mm-1. ha-1 was observed in the second year and cattle manure treatment. In this research dry matter yield and precipitation efficiency increased by using cattle manure and high plant density in the second year. In general, adaptive capacity and adequate yield of Bakhtiari savory showed the high precipitation efficiency index of this species, which can be used as a suitable species for dryland agriculture. These results can be remarkably beneficial to change the cultivation pattern in low-efficiency dryland farming.