Effect of Application of Different Levels of Chemical Fertilizers and Pelleted Poultry Manure on Yield and Quality of Sunflower )Helianthus annuus L.( Nuts under Sanandaj Conditions

Utilization of different plant nutrition systems in terms of optimal use of climatic factors, agricultural management and consumption of agricultural inputs can be an effective help to increase production and reduce the use of chemical fertilizers. Under such conditions, the use of organic manures can protect the environment and produce healthy agricultural products and provide better nutritional conditions for crops and have a favorable effect on plant growth. Organic manures are natural and safe products. Organic manures have positive effects on plant growth by increasing porosity and permeability, reducing soil bulk density and increasing soil water-holding capacity. The combined use of chemical and organic fertilizers, as a correct and rational management system, in addition to reducing the use of chemical fertilizers and preventing their harmful effects on surface and groundwater, can maintain the nutritional balance in plants and increase their yield. Recognizing the significance of integrating organic and chemical fertilizers in sustainable agriculture, this study was undertaken to examine the variations in yield and yield components of sunflower nuts. The investigation focused on the utilization of different levels of chemical fertilizers and pelleted poultry manures.

This experiment was performed as a randomized complete block design with 11 treatments in three replications in the research farm of University of Kurdistan in 2018. Experimental treatments including poultry manure in combination with chemical fertilizers including 1000 kg of poultry manure + zero chemical fertilizer, 1000 kg of poultry manure + 25% of recommended chemical fertilizer, 1000 kg of poultry manure + 50% of recommended chemical fertilizer, 2000 kg poultry manure + zero chemical fertilizer, 2000 kg poultry manure + 25% of recommended chemical fertilizer, 2000 kg poultry manure + 50% of recommended chemical fertilizer, 4000 kg poultry manure + zero chemical fertilizer, 4000 kg poultry manure + 25% of recommended chemical fertilizer, 4000 kg Poultry manure + 50% of recommended chemical fertilizer, 100% chemical fertilizer application (recommended) and no fertilizer application. In this experiment, traits such as plant height, head diameter, 1000-seed weight, number of seeds per head, biological yield and grain yield were measured.

The experimental results highlighted the positive impact of combined poultry and chemical fertilizer treatments on both grain yield and yield components. This included an increase in the number of grains per head, maintaining a 1000-grain weight by enhancing the number of grains per head, boosting biological yield, grain yield, and harvest index. Additionally, improvements were observed in grain quality, with elevated protein, oil, phosphorus, and potassium content in sunflower seeds. Notably, the most favorable outcomes in terms of grain yield were observed in plants treated with 4000 kg of poultry manure + 25% chemical fertilizer (1413 kg/ha-1), those without poultry manure + 100% chemical fertilizer (1411.2 kg/ha-1), and those treated with 4000 kg of poultry manure + 50% chemical fertilizer (1367.07 kg/ha-1). These treatments exhibited the highest grain yield, representing a substantial increase of 60.57%, 60.3%, and 54.55% compared to the control treatment (880 kg/ha-1). Treatments of 4000 kg poultry manure + 25% chemical fertilizer, no poultry manure + 100% chemical fertilizer and 4000 kg poultry manure + 50% chemical fertilizer had the highest percentage of harvest index, respectively. Treatments of 1000 kg poultry manure + 25% chemical fertilizer, 2000 kg poultry manure without chemical fertilizer, 1000 kg poultry manure without chemical fertilizer and also control treatment had the lowest percentage of harvest index. Treatment application of 1000 kg poultry manure + 25% chemical fertilizer (39.84%) had the highest percentage of seed oil, but there was no significant difference with other fertilizer treatments and only with control treatment (32.91%) had a significant difference. The highest amounts of grain protein, phosphorus and potassium were obtained from the combined treatment of 25% chemical fertilizer + 2000 kg of poultry manure.

In general, due to the negative effects of chemical fertilizers, the combined treatment of 4000 kg.ha-1 of poultry manure + 25% of the recommended chemical fertilizer with the highest grain yield was the best fertilizer treatment. From the results of this study, it is inferred that using organic and chemical fertilizers in sunflower cultivation, in addition to achieving acceptable yields and improving grain quality, can increase the efficiency of fertilizer application and use chemical fertilizers that have negative effects on the environment and environment. Crop systems have proven to shrink and move towards achieving sustainable agricultural goals.