Comparative evaluation of the effect of organic and mineral fertilizers on yield, yield components and growth indices of rice (Oryza sativa L.)

To study the effect of chemical fertilizer and chicken manure on yield and yield components of rice cv. Hashemi, a field experiment was conducted in randomized complete block design with three replications at Rice Research Institute of Iran (RRII), Rasht, Iran, in 2017. The studied fertilizer treatments were chicken manure (33 t.ha-1), chemical fertilizer (recommended by RRII) and control (no-fertilizer). The studied traits included grain yield, 1000-grain weight, filled grain percentage, number of total tiller per plant, number of fertile tiller, SPAD value, stomatal conductivity and some growth indices. The results indicated that the highest grain yield (3664 kg.ha-1), 1000-grain weight (23.31g), filled grain (96.6 %) and total dry matter (900 g.m-2) were obtained from chemical fertilizer. In contrast, the use of chicken manure produced the highest flag leaf length (40.6 cm) and the highest net assimilation rate (4.6 g.m-2.day-1). Application of chicken manure caused the leaf area index (LAI) to decrease than other treatments. The highest specific leaf area (SLA) was observed in chemical fertilizer. SLA was less in chicken manure at the beginning of the growth period, but over time and reaching next growth stages, it approached to chemical fertilizer. The highest LAI and leaf greenness (SPAD value) obtained from chicken manure application, but the highest stomatal conductivity was observed in chemical fertilizers. According to results of this research, although the application of chemical fertilizers more increased the yield and improved the yield components than chicken manure, but application of chicken manure could be improved the net assimilation rate (NAR), flag leaf length, LAI and SPAD than chemical fertilizer. Probably due to the more greater value of nutrients in chemical fertilizer than chicken manure, the yield produced by chemical fertilizer was higher than chicken manure. In total, according to the harmful environmental effects of chemical fertilizer and the not-significant reduction of grain yield of rice cv. Hashemi in chicken manure treatment, chicken manure instead of chemical fertilizer is recommended.