Some Soil Characters and Qualitative Traits of Sunflower Seeds to Different Nutritional Regimes

IntroductionTo achieve the high economic yield in crops, supplying enough nutrients for plants is important, that much of it, supplied by chemical fertilizers. But excessive use of chemical fertilizers led to environmental problems that these negative effects have caused attention to healthy and ecological sustainable farming systems. One solution to reduce dependence on chemical fertilizers is application of organic and biological products for plant nutrition. Bio-fertilizers are made from one or more species of beneficial microorganisms with preservatives and or their products. In addition, vermicompost is an organic fertilizer and mixed of very active biological bacteria, enzymes, plant residues, manure and earthworm capsule which leads to continued organic matter decomposition and development of microbial and enzymatic activities in soil. Several experiments have shown that the using of biological and organic fertilizers improve growth and quality of products.
Materials and MethodsTo investigate the effect of various nutritional regimes on seed quality characteristics of sunflower (Euroflour cv.) and some soil characters, an experiment was carried out as a randomized complete block design with 3 replications in 2015 at the Agricultural Faculty of Bu-Ali Sina University.Treatments included no biological or chemical fertilizer application, 100% of the recommended NP fertilizers (250 kg urea per hectare, 50 kg triple superphosphate per hectare), ½ recomended NP fertilizers, vermicompost (15 ton per hectare mixed with soil), phosphonitrokara (including Bacillus coagulans, Azotobacter chroococcum, Azospirillum lipoferum, 110 ml to inoculate 10 kg seeds), biosulfur (including Thiobacillus,mix 6 kg of fertilizer with 300 kg sulphur for 1 hectare), vermicompost phosphonitrokara, vermicompost biosulfur, vermicompost½ NP fertilizers, phosphonitrokara½ NP fertilizers, biosulfur½ NP fertilizers, vermicompost phosphonitrokara½ NP fertilizers, vermicompost biosulfur½ NP fertilizers. Concentrations of nitrogen, phosphorus and sulfur of sunflower seeds and soil were measured by standard methods. Moreover, seed oil content was determined. Data processing and graphs were performed with SAS var 9.2 and Excel software.
Results and DiscussionThe results showed that nutritional treatments significantly affected all traits except seed oil content and soil pH. The maximum seed sulfur content (0.231%) belonged to biosulfur vermicompost treatment indicating that providing sulfur for sunflower of oxidation in soil increased the concentration of seed sulfur. The highest phosphorous (0.45) obtained from phospho nitro kara vermicompost and biosulfur vermicompost ½ NP fertilizers. Secretion of different enzymes such as phosphatase by rhizobacteria led to solubility and increasing available phosphate. Maximum nitrogen (2.688%) and protein (16.8%) content of seed was observed in phosphonitrokara vermicompost ½ NP fertilizers treatment. It seems that bacteria in the biological and organic fertilizer along to chemical fertilizer by nitrogen fixing provided the necessary substrate for protein synthesis. According to grain yield, the highest oil yield was achieved in chemical fertilizer that there was no significant difference with biosulfur vermicompost ½ NP fertilizers. Likely, the positive effects of thiobacillus on oil seed was related to the appropriate turnover of photosynthesis enzymes, activity improvement of acetyl-CoA and increasing availability of carbon for oil biosynthesis. Maximum total sulphate, available phosphorus and total nitrogen content of soil was observed in biosulfur vermicompost, phosphonitrokara vermicompost ½ NP fertilizers and phosphonitrokara vermicompost ½ NP fertilizers, respectively. In treatments includes vermicompost due to increasing soil organic matter, humus colloids and carbon availability for activity of nitrogen fixing bacteria was occurred less leaching and increased maintenance and fixation of nitrogen in the soil. Soil pH was not affected by treatments. The finding showed that reduction of pH must be done during the process of long term and sulfur to be added to soil plenty and in times.
ConclusionsIn general, we can suggest that biological (phosphonitrokara andbiosulfur) and organic (vermicompost) fertilizers along with chemical fertilizers by modifying the nutritional conditions of soil and reduce the use of chemical fertilizers can be effective in stability of production and conservation of environmental health.