To investigate the effect of vermicompost, N fertilizer and their integration on growth, biological and essential yields oil and its components in two populations (Varamin and Isfahan), an experiment was conducted in a randomized complete block design with three replications in the field of Isfahan Medicinal Plants Research Center in 2016. Fertilizer treatments including 100% urea, vermicompost 33.3 and urea 66.6%, vermicompost 66.6 and urea 33.3%, 100% vermicompost and control treatment (without fertilizer) as the first factor and Varamin and Isfahan populations as the second factor were selected. The results showed that the interaction effects of nitrogen fertilizer and populations on all studied traits were significant. In both populations, nitrogen fertilizer improved height, biological and essential oil yields, content of essential oil compounds (d-Carvone and its yield, α-phellandrene and linalool; except p-Cymene and Limonene in Isfahan population). Since in medicinal plants, the quantity (biological yield) and quality (essential oil and d-Carvone; the most important ingredient and the highest amount of essential oil in this experiment), 66.6% vermicompost + 33.3% urea in Varamin population, was the best treatment in the experiment. In addition an in the direction of human health and sustainable agriculture, it is possible to reduce 33% of chemical fertilizers application and pollution; however, in terms of other essential oil contents (α-phellandrene, Linalool and p-Cymene), 100% vermicompost fertilizer treatment was superior in Isfahan population.

Estimation of optimum fertilizer rates is needed because of growing economic and environmental concerns. Optimum fertilizer rates can be determined by fitting statistical models to yield data collected from N fertilizer experiments. The main goal of this research was to compare and evaluate quadratic, square root, Mitscherlich, rectangular hyperbola, linear plus plateau and quadratic plus plateau models for describing the response of sugar beet to N fertilizer. Data used were obtained from a furrow irrigation system experiment with five N fertilizer rates: zero (control), 60, 120, 180, and 240 N kgha-1 with three replications in Ekbatan Research Station, Hamedan, Iran, during 2003 and 2004. Economic optimum N fertilizer rates were obtained based on fertilizer and sugar beet price during 2003 and 2004. Economic, optimum N fertilizer rates varied depending on the fertilizer to crop price ratio and models used. Results of this research showed the quadratic model described the yield responses and economic, optimum N fertilizer rate in sugar beet cultivation better than the other models. Economic, optimum N fertilizer rates due to this model were 235.8 and 248.9 kgha-1 in 2001 and 2002, respectively. Economic optimum N fertilizer rates based on N fertilizer subsidy and non-subsidy prices were 234.7 and 225.1 kgha-1 for 2003 model, and 247.9 and 240.8 kgha-1 for 2004 model, respectively.

To investigate the response of corn to combined application of chemical fertilizers with rhizobacteria plant growth promoting, an experiment was conducted in 2017 at Research farm of Agricultural and Natural Resources Campus of Tehran University, Karaj, Iran, in a randomized complete block design with four replications. Four nutritional treatments including T1 (Control treatment without applying fertilizer), T2 (Just PGPRs), T3 (Use chemical fertilizers based on soil test) and T4 (T3 + PGPRs) were considered. According to the results, the highest total dry weight (3.9 kg/m2), crop growth rate (79.8 g.m-2.day-1), net assimilation rate (15.3 g.m-2.day-1) and grain yield (18.2 ton.ha-1) were observed in T4 treatment and T2 treatment produced the highest  leaf area index (5.3), leaf area duration (205.2) and specific leaf weight (78.5 g.m-2) . Also, the lowest value of all traits was observed in in T1 (control) treatment. The results showed that the presence of rhizobacteria plant growth promotioninduction in the corn nutrition program increased the growth and growth indices of the plant. Combined application of chemical fertilizers with rhizobacteria plant growth promoting resulted in the highest growth and final grain yield of corn.

To investigate the effects of fertilizer regimes on quantitative and qualitative traits of Dracocephalum kotschyi Boiss, a field experiment at three replications with the Split Plate arrangement in a completely randomized block design was conducted in the Research Field of Tarbiat Modares University during the 2017-18 growing season.Water deficit stress (irrigation after discharging 20 (optimal irrigation), 40 (mild water deficit stress), 60 (moderate water deficit stress) and 80% (severe water deficit stress) of water used (available water)) in the main plot and fertilizer regime (urea, nitroxin, vermicompost, azocompost and no fertilizer) in the subplot were studied. The results showed that the highest leaf fresh weight (1797 kg ha-1) and total biomass (2957 kg ha-1) were obtained by application of urea in mild water deficit stress condition and the highest dry matter digestibility percentage was observed in azocompost treatment in moderate water deficit stress condition (57.8%). The highest crude protein was produced in severe water deficit stress condition (19.72%) and moderate water deficit stress (18.4%), respectively.. The highest percentage of water soluble carbohydrate and neutral detergent fiber were obtained from no fertilizer in moderate water deficit stress (22.06%) and application of urea in severe water deficit stress conditions, respectively. Mild water deficit stress application to produce high biomass is recommended for Dracocephalum kotschyi Boiss. According to the results, application of urea in mild water deficit stress was selected as the best treatment to produce forage 32% more than control.

Fertilizer is known as an important factor in agricultural production since many years ago. Use of chemical fertilizers in Iran started more than 50 years ago and has grown during recent years. Nowadays, issues such as fertilizer quality, distribution, scientific recommendation, methods of application, environmental effects, and chemical residues in crops are very important concerns. Fortunately, attention to “fertilizer” as a subject in national laws and legislations has grown during recent years and, in contrast to earlier years when the focus was just on supply and distribution, nowadays, issues like quality controls and environmental effects are receiving attention as well. However, lack of a comprehensive national law and management system as a regulator of different fertilizer system parts is clear now. Assessment of fertilizer system including production, distribution, application, import and export, and related standards shows that “Comprehensive National Law”, “Institution Responsible for Fertilizer Management” and “National Quality Standards for Different Kinds of Fertilizers” are three important missing components in fertilizer management system.

To investigate the effect of application of bio-fertilizer (Barvar-2) and possibility of replacement with phosphorus chemical fertilizer a factorial experiment performed based on completely randomized block design with three replication in Agricultural station of Islamic Azad University of Tabriz during 2014. Experimental treatments consisted of phosphorus biological fertilizer in two levels (without and application of Barvar-2) and chemical fertilizer in three levels: 0, 50 and 100% of recommended dose according to soil analysis (equal 75 kg. ha-1). The results showed that the two phosphorus fertilizer levels were same increase on grain yield and this trait and increased about 34 and 33. 1 as compared to control respectively. Level of 50% of phosphorus chemical fertilizer via increase of grain number in bush and 100% grain weight caused increase in grain yield. While in comparison level of 100% phosphorus chemical fertilizer only with increase in number of grains were increased grain yield. The amount of increase in grain number in bush under 50 and 100% of phosphorus chemical fertilizer was 18. 7 and 31. 2% respectively. The 100-grain weight of lentil increase 17% with application of 50% phosphorus chemical fertilizer. For traits: Leaf area index, Chlorophyll index and Dry weight of leaf were not significantly different between 50 and 100% of phosphorus chemical fertilizer. Application of biofertilizer had the significant effect in grain yield of lentil. Application of Barvar-2 had 18. 2% increases in grain yield of lentil in comparison with control. Increase in grain yield under effect of bio-fertilizer application only in relation to increase in grain number in bush and 100-grain weight not affected. With regard to these results, it can be said that application of 50% phosphorus chemical fertilizer with Barvar-2 had optimum amount in grain yield of lentil and that suggested for this region.

Increasing demand for food production in the recent years has raised the usage of granular fertilizers.Consequently, the growing use of fertilizers has reduced the quality and quantity of crop production. In addition pollution problems such as soil and water (surface and subterranean water) contaminations has increased.Consistent spreading of fertilizers in the farmlands is of fundamental rules in conventional framings. In present study, the effects of the number and the arrangement (position) of blades of a single disk fertilizer distributer and for two different fertilizers were investigated in order to obtain optimized distribution of fertilizer. The tests were conducted in factorial arrangement and in a completely randomized model. The variables were the number of blades in three levels of 4, 6 and 8, the blade position angles (in two patterns of radial and non-radial) and the type of fertilizer (phosphate and nitrate). Statistical analysis of results indicated that the number of blades on the disk and type of fertilizer are not effective parameters in order to reach a consistent distribution pattern of fertilizer while the position of blades on the disk has significant influence for this purpose. The best pattern of distribution was obtained from the disk with four non-radial blades and nitrate fertilizer.

In order to evaluate organic phosphorus fertilizer and phosphorus biofertilizer Barvar 2, as a substitute for chemical P fertilizers in wheat production, an experiment was conducted during two growing seasons of 2005-06 and 206-07, in a field in Bardsir city, Kerman Province, using a randomized complete block design with 12 treatments and 3 replicates. Treatments were T1=150 kg/ha organic P fertilizer +100gr Barvar 2, T2=100 kg/ha organic phosphorus fertilizer +100gr Barvar 2, T3=50 kg/ha organic phosphorus fertilizer +100 gr Barvar 2, T4=50 kg/ha organic phosphorus fertilizer,T5=100 kg/ha organic P fertilizer, T6=150 kg/ha organic phosphorus fertilizer,T7=50 kg/ha triple super phosphate +100gr Barvar 2 ,T8=100 kg/ha triple super phosphate +100gr Barvar 2, T9=150 kg/ha triple super phosphate +100gr Barvar 2, T10=50 kg/ha triple super phosphate,T11=100 kg/ha triple super phosphate and T12=150 kg/ha triple super phosphate. The measured properties were: grain yield, ears/m2, grains per ear, thousand kernel weight and soil phosphorus after harvest. According to the results, the highest yield (8477 kg/ha) was obtained by application of Barvar 2 together with 150kg/ha organic phosphorus fertilizer, which showed a yield increase of 58.4% in comparison with the control treatment i.e. 50 kg/ha triple super phosphate(T10) (local practice based on soil analysis). The highest yield components measured were 43.3 gr thousand kernel weight, 466ears/m2, and 47.67 grains per ear in treatment T1, which, in comparison with the control, showed an increase of, respectively, 28.3%, 39.2% and 32.9%. The highest phosphorus fixation in soil was 9.78 mg/kg and belonged to the treatment of 150 kg/ha triple super phosphate(T12), which had no significant difference with treatments T11.

In order to study the effects of different soil nutrition methods and plant growth promoting rhizobacteria (PGPR) on grain and oil yield and fatty acid composition in sunflower (Helianthus annuus L.), a field experiment was conducted on research farm at college of agriculture, Tarbiat Modares University, Tehran in 2006-2007 and 2007-2008 growing seasons. The experiment was studied in a split plot arrangement of treatments in a randomized complete block design with three replications. Five fertilizer treatments including 100% organic (F1), 75% organic+25% chemical (F2), 50% organic+50% chemical (F3), 25% organic+75% chemical (F4), 100% chemical (F5) were randomized to the main plots and two treatments of non-bacterial inoculation (I0) and bacterial inoculation (I1) were randomly assigned as the subplots. The results showed that integrated treatments produced significantly more grain, biological and oil yield and protein content than those grown in each of organic or chemical treatments. The maximum and minimum oil contents (51.1% and 46.3%) were obtained with the 100% organic and 50% organic+50% chemical treatments, respectively, whereas the same treatments were in the converse position for protein content (20.9% and 18.3%). Saturated fatty acids decreased significantly, while unsaturated fatty acids (linoleic acid and oleic acid) increased in response to raising the organic manure and using biofertilizer. The highest linoleic acid (52.6%) and oleic acid (39.8) were observed in 50% organic+50% chemical and 100% organic treatments, respectively. Application of biofertilizer increased the grain (7.8%), oil (11.3%) and biological yield, and also protein (4.9%) and oil (2.6%) content and improved the oil quality of sunflower seeds. Therefore, it seems that sunflower productivity and seed oil quality can be improved using different nitrogen nutrition methods.