Study on the effect of urea fertilizer, iron sulphate and vermicompost on yield and growth properties of sunflower (Helianthus annuus L.) in Darreh Gaz distric

Most important factor limiting plants growth in agriculture is deficiency of nitrogen as compare to other nutrients. Plant needs to nitrogen is due to reason that nitrogen after hydrogen is largest elements in plant that absorbed from soil. Nitrogen in soil especially in surface layer is more and in the form of organic composition, therefore nitrogen accumulation in soil has direct relationship with organic matter accumulation. Soil organic matter in the in our country are low due to different reasons including low rain fall, unsuitable cultivation rotation. Urea is one of the nitrogen sources which its uses extended all over the world in agriculture sector. Nitrogen is one of the important nutritious mineral matters for plant growth and is a suitable source for increasing yield especially in improved varieties. At present due to economical problems in cost of chemical fertilizers in one side and environmental effects of high consumption on the other side are the difficulties of sustainable agriculture (Mulvaney et al., 2009). Ngo et al. (2012) showed that mineral fertilizers application had negative effects on soil like soil acidifying, drainage loss and decreasing microbial biomass. Displacement of mineral fertilizer with organic compounds like compost can reduce negative effects. Composts are organic material which has lots of advantages. Results of different studies showed that compost cause better soil fertility (Caravaca et al., 2002). Sunflower (Helianthus annuus L.) is one of five oil plants which is resistant to drought and adaptable in different climate of the country, growth and develop in different soil. Also high oil quality, low growth period after wheat and barley and its cultivation as a second crop cultivation. For reaching these aims we should understand how its effect the high absorption efficiency of nutrient mineral and other factors affecting and ways to achieve them. For the reaction of sunflower to different levels of urea fertilizer and iron sulphate in the presence and non presence of vermicompost, a field experiment conducted in Darreh Gaz district (Khorasan Razavi province) in 2013. This experiment was in the form of factorial on the bases of complete randomized block design with three factors and three replications. In this experiment three level of urea fertilizer including, 50, 150 and 250 kg.ha-1 as main factor and two levels of iron sulphate including zero and 80 kg.ha-1 as second factor and vermicompost in two levels zero and 7 t.ha-1 as third factor. Nitrogen treatment was applied in three stages. First stage was 1/3 of urea application at seeding stage. Second stage was at 8 leaf stage and application second 1/3 of urea and last 1/3 of urea applied at flowering stage. Iron sulphate treatment totally applied at flowering stage. Seeds were sown at depth of 3-5 cm on the furrows; plots had 4 lines for cultivation with the length of 6 meter. Distance between lines was 50 cm and distance between plants was 20 cm. At the end of season growth properties of plant like, plant height, stem diameter, tray diameter, leaf dry weight, leafstalk dry weight, stem dry weight, tray dry weight were measured. Statistical analysis were done with SAS ver. 9.1 and figures were done with excel. Mean comparison at 5% level were done with LSD test. Plant height, interaction effect of nitrogen and vermicompost on sunflower stem height was significant at 1% level. Highest stem observed at 250 kg.ha-1 nitrogen and zero vermicompost application. Conjoint effect of nitrogen and iron sulphate on plant stem height was significant at 1% level. It seems that increase in nitrogen level cause better plant photosynthesis and finally higher plant height. Interaction effect of three factors had significant effect at 5% level on plant stem height. Composition effect of nitrogen and vermicompost on stem diameter was significant at 5% level. Lowest stem diameter achieved at 50 kg.ha-1 nitrogen and zero vermicompost application. Effect of nitrogen and iron sulphate on stem diameter were significant at 5% level. Interaction effect of vermicompost and iron sulphate was significant at 5% level. Interaction effect of nitrogen and vermicompost on tray diameter was significant at 1% level. Also interaction effect of vermicompost and iron sulphate on tray diameter was significant at 1% level. (Rahimizadeh et al., 2010) showed that micro element application to sunflower had significant effect on tray diameter. Three factor interaction on tray diameter were significant at 1% level. Sunflower verities had different reaction to nitrogen application. Interaction between nitrogen and vermicompost had significant effect on yield at 1% level. Highest yield were 7.73 t.ha-1 with interaction of nitrogen (250 kg.ha-1 and vermicompost at 7 t.ha-1). Results showed that combination of vermicompost and iron sulphate along with different levels of urea compared to single effect of them needs more investigation. Vermicompost application as improve soil properties like porosity, available moisture and nutrient elements can improve the plant growth and better fertilizer use efficiency. Therefore it seems that conjunction of chemical fertilizer and vermicompost can improve sunflower growth in Darreh Gaz District.