Evaluation of Cow Manure and Different Nitrogen Sources on Yield and Nitrogen Use Efficiency in Safflower (Carthamus tinctorius L.)

One of the major factors restricting the crop production is nitrogen. Nitrogen has an important role in achieving maximum yield and it improves the yield and quality of all crops (Ullah et al., 2010). In the arid and semi-arid regions of Iran, the deficiency of organic matter in the soil as the natural resource required by the plant and the moisture tension, are the major factors of absorbing nitrogen and after moisture tension, nitrogen tension is the major limiting factor of crop production (Sadri, 2017). Nitroxin fertilizer contains nitrogen fixing bacteria that fix the air nitrogen, balance the high-consumption and micronutrient elements, synthesis and secretion of plant growth stimulants and as a result, protection of plant against pathogens, biological and non-biological stresses.One way to examine the efficiency of the fertilizers, especially nitrogen, is studying nitrogen use efficiency. This indicator shows the increase in yield by each unit increase in the input (Delbert and Ulter, 1989). One way to manage different nutritional resources is to evaluate the nitrogen use efficiency. This study aims to evaluate the function and indicators of nitrogen efficiency in manure treatments and different resources of nitrogen in safflower.

This experiment was conducted as randomized complete block design with three replications in the research farm of faculty of agriculture university of Jiroft in 2018-2019 year. The first factor included different sources of nitrogen fertilizer in six levels of urea fertilizer, urea with sulfur coating, ammonium nitrate, nitroxin, nano nitrogen and control, the second factor included animal manure in two levels of consumption and non-consumption was considered. The intra row and inter row distance was 30 and 10 cm respectively with 2×3 m2 plot size. Drip irrigation was used and during the different plant growth stages, no chemical pesticide and herbicide was used nitrogen of seed, leaf and shoot was carried out using Kjeldhal method. Data were analyzed by SAS software version 9.4. Mean values were compared according to Duncan test at P < 0.05.

The results showed that manure and difference resource of nitrogen has significant effect on the seed yield, seed nitrogen percentage, biomass, plant nitrogen content, the efficiency of use, physiological, absorption, productivity and nitrogen harvest index in safflower. The highest nitrogen in seed (3.46%), biomass (1.05%), seed yield (284 g.m-2), seed nitrogen content (1138.8 g.m-2), and biomass nitrogen content (752.5 g.m-2) obtained in manure + nitroxin treatment. the results indicated the positive and significant effect of manure and biological fertilizer on the improvement of yield and nitrogen efficiency. The interaction of manure and different nitrogen fertilizers on seed yield was significant. The highest and lowest seed yield obtained by manure + nitroxin treatment (284 g.m-2) and not using manure and control treatment (68.3 g.m-2) respectively.In safflower, using nitrogen fertilizers can increase seed yield by affecting the branches of the plant (Weiss, 2000). The researchers reported that the use of nitrogen, compared to control (not using nitrogen) increased safflower seed yield.According to the results, manure treatment compared to not using manure treatment showed 24.3% increase in seed nitrogen. Nitroxin and nano nitrogen fertilizers have the highest seed nitrogen percentage (3.46 and 3.21, respectively) and the lowestnitrogen was in control treatment (1.9%). Manure + nitroxin treatment had the highest nitrogen in biomass and plant. In safflower, the use of manure increased the absorbed nitrogen percentage compared to control treatment (Ghanbari et al., 2016). In this regard, the researchers observed the increase in absorption efficiency and use of nitrogen in saffron through using organic fertilizers compared to chemical fertilizers. The results of this research showed that using biological fertilizers, especially nitroxin, has positive effect in increasing seed number in plant, seed yield, days to maturing, nitrogen percent, absorbed phosphorous by plant and nitrogen physiological efficiency (Arab-Niasar et al., 2019).

The results of this experiment showed that using manure and biological fertilizer improves nitrogen efficiency compared to not using manure condition. It seems that the combined use of manure with chemical fertilizers reduces the loss and washing nutritional elements, especially nitrogen. The use of organic fertilizers to improve soil structure, maintain water and access to required elements by plants should be considered as a priority. Regarding the highest yield in manure + nitroxin treatment, it is suggested to use nitrogen fertilizers with biological origin.