عصاره جلبکی

Improper use of chemical fertilizers to increase the yield of various crops has caused numerous damages in various fields .The international community is moving towards the use of fertilizers and bio stimulants in the form of organic agriculture in order to reduce the risks and harms caused by the use of chemical fertilizers and at the same time maintain crop yields. In order to investigate the effect of urea chemical fertilizer and foliar application of Ulva fasciata Delile seaweed extract on growth factors of alfalfa (Medicago sativa L.), A Split plot study was conducted in the form of a randomized complete block design with 3 replications in Shavour Agricultural Research Station and Plant Physiology Laboratory of Shahid Chamran University of Ahvaz in 1399-1400. The treatments for this experiment included different concentrations of 4 levels urea fertilizer (0, 40, 70 and 100% of the usual amount of urea fertilizer) and different concentrations of 4 levels ulva seaweed extract (0, 5, 10 and 15%). Different concentrations of urea chemical fertilizer were used as soil application and different concentrations of ulva seaweed extract were used as foliar application. The treated plants were examined in the beginning of reproductive phase. The results were statistically analyzed by MSTAT-C software. Comparison of the mean interaction of urea fertilizer and seaweed extract showed that the application of 15% ulva seaweed extract along with 70% of the usual amount of urea chemical fertilizer leads to an increase in the desired factors compared to other treatments. In addition, malondialdehyde a level in plants treated with ulva seaweed extract were decreased. Based on this, it can be said that foliar application of 15% seaweed extract has an effect almost similar to half of the usual application of urea chemical fertilizer.

Irregular use of chemical fertilizers and lack of attention to the importance and positive effects of organic materials in improving the fertility of agricultural soils has been resulted in environmental pollution and ecological damage. Therefore, biological resources should be used to reduce these risks to increase the availability of nutrients elements and improve the physical and microbial conditions of the soil. One of the biological resources is marine algae which are rich in materials needed for plant growth. In this study, the effect of alga (Ulva fasciata L.) extract has been investigated on some physiological parameters of Sesamum indicum L. Experiment was conducted using randomized complete block design with 4 replications by different concentrations of  alga extract (0, 10, 15, 20 %) in field condition. According to the obtained data, most of the traits physiological such as stem length stem diameter, leaf area and biochemical parameters including CO2, soluble sugars, prolin and phenol significantly increased in different treatment of alga extract compare to the control .The best results of the studied parameters were observed in the concentration of 20%. Aga extract with having essential plant elements and growth hormones, without damage to nature as a bio-fertilizer can be a good alternative to chemical fertilizers and can have an important role in managing the supply of healthy food.