Agro- physiological responses of Carthamus tinctorius L. to sources of nitrogen fertilizer and organic manure

Excessive consumption of nitrogen (N) to enhance production, which may lead to environmental pollution. While sustainable production is threatened due to low soil fertility and organic matter. This study was carried out as a factorial experiment in the randomized complete block design and three replications at the research field of the University of Jiroft in 2018-2019. The present study investigates the effects of sources of N fertilizers and cow manure on safflower products in the arid climates of Iran. Two levels of cow manure (0 and 30 t ha-1), and six levels of sources of N fertilizer (control, 130 Kg ha-1 N from the sources of urea with a sulfur coating, ammonium nitrate, nano-N, urea, and 1L nitroxin per Kg grain) were used according to the results of soil analysis. Interaction of cow manure and different sources of N fertilizer increased 32-47 % SPAD index at the late vegetative and 37-50 % at the early reproductive stage, 58-81% oil percent and oil yield, 28-81% protein yield, 42-57 % plant height, 52-72 % lateral branches number and 49-78 % grain yield compared to the control. Among the sources of nitrogen fertilizers, nitroxin, nano N, urea with a sulfur coating, ammonium nitrate, and urea had a more positive effect on evaluated characteristics, respectively. There was a significant positive correlation (P≤0.01) between yield components. The best result in this study, earned by simultaneous use of cow manure to the soil and inoculating the grains to nitroxin before being planted. Therefore, the simultaneous use of organic and biological fertilizers, in addition to reducing environmental pollution due to the non-use of chemical fertilizers and reducing production costs, can produce healthy products and byproducts of safflower in arid climates.