Evaluation of the Integrated Effect of Organic, Chemical and Biological Fertilizers on Yield of Marshmallow (Althea officinalis L.) as a Medicinal Plant

Medicinal plants have an important role in different industries. So, increasing production of their yields is necessary. Medicinal plants contain phytochemical compounds which have demonstrated bioactive properties. The active principles of the plants are generally secondary metabolites. The use of ecological farming methods, may improve yield and quality. In the last decade, agricultural production, which is mainly based on the use of chemical material, is causing environmental problems. One of the pathways to mitigate this environmental impacts, is to apply the long-term approaches based on the principles of ecological agriculture. Soil microorganisms are the primary metabolites production in the soil can affect the results in the release of phosphorus. Compost can be used as an organic matter in controlling different types of debris and the reduction in fertilizer consumption in agricultural products and mineral absorption elements improve low consumption by plants. Present study aims to investigate the possibility of improving the growth, flower yield, shoot yield, seed yield and yield components of marshmallow as a medicinal plant affected as integrated management of organic, chemical and biological fertilizers. A field experiment was performed as factorial layout based on a randomized complete block design with three replications at Agricultural Research Station, College of Agriculture, Ferdowsi University of Mashhad, Iran, during growing season of 2012-2013. The experimental treatments were all combination of organic and chemical fertilizers in four levels (cow manure (40 ton.ha-1), urban compost (40 ton.ha-1), NPK as chemical fertilizer (114, 18 and 220, 40 kg.ha-1) and control) and inoculation with Thiobacillus and sulphur application in four levels (including inoculation with Thiobacillus, 200 kg.ha-1 sulphur + inoculation with Thiobacillus, 200 kg.ha-1 sulphur and control). plant height, leaf areal indexmax (LAImax), leaf dry weight, stem dry weight, total dry weight, flower, seed yield and yield components such as branch number, capsule number, number seed per capsule and 1000-seed weight and flower, seed and biological yield of marshmallow.
To analyze the variance of the experimental data and drawing of diagrams, MSTAT-C 8 and Excel software was used. All the averages were compared according to Duncan’s multiple range test (p≤0.05) The results showed that the effect of organic, chemical and biological fertilizers were significant (p≤0.01) on plant height, LAImax, leaf dry weight, stem dry weight, total dry weight, flower and seed yield, yield components and biological yield of marshmallow. At the end of the growing season, the highest and the lowest LAImax were observed in chemical fertilizer with Thiobacillus +sulphur (12.3) and control (1.3). The maximum flower and seed yields were recorded in chemical fertilizer with Thiobacillus +sulphur (175.33 and 99.91 g.m-2, respectively) and the minimum were obtained in control treatments (32.33 and 9.31 g.m-2, respectively). Flower yield enhanced up to 100% under chemical, cow manure and compost fertilizers without Thiobacillus +sulphur, Thiobacillus, sulphur compared to control treatment. Flower yield improved up to 106, 89 and 72% for chemical fertilizer, cow manure and compost application with Thiobacillus +sulphur, respectively. According to the results obtained in the present study, organic, chemical and biological fertilizers had significant effects on growth, shoot yield, flower yield, seed yield, biological yield and yield components of marshmallow. Therefore, due to the high pH of soils in agroecosystems, integrated application of sulphur with Thiobacillus inoculation could be considered as an effective approach for soil fertility improvement. organic matter increase soil water holding capacity, improving plant hormone-like activity, increase nutrient uptake by plants, and generally improve the growth and yield of medicinal plant.