Effects of Azolla Combined with Organic and Inorganic Fertilizerson Growth Index of Populus deltoides

Azolla plants with the capability of fixing nitrogen, potassium and phosphorus, which are used as green manure and the nutrients in the compost, can be considered as a source of nutrition for plants. This study was designed to investigate the combined effects of Azolla with organic and inorganic fertilizers on soil NPK levels on study the growth index of Populous Deltoids. The Azolla were collected from ponds of Joibar city located in Mazandaran province. Azolla compost was used in combination with inorganic and organic materials and the amount of NPK in these compounds and its effects on growth parameters (height, stem diameter and leaf fresh weight) were investigated. The compost of Azolla 100% and straw 100% had the highest and the lowest NPK that resulted in significant increases in growth indices of Populus deltoides in comparison with control one. Growth Indices in the compost of Azolla 100% showed the significant increase in comparison to other fertilizer treatments (different percentages of Azolla, straw and urea). Also, the mixed manure of Azolla and organic compost (Azolla 50%+ straw 50%) (With 0.32% nitrogen, 0.02% phosphorus and 0.24% K) with inorganic fertilizer of urea was significantly increased growth parameters of plant than control. According to the results, compound fertilizer 50% Azolla +50% straw + urea and Azolla 100% compost were had the greatest impact on improving the soil and finaly, plants growth. Therefore, use of green manure and green manure combined with a combination of organic and inorganic fertilizers, according to the effects on soil chemical traits, resulted in fertility improvement and increase of crop and by reducing the use of chemical fertilizer in agriculture will prevent environmental pollution and its staggering costs and contribute to the sustainable development of agriculture.