Title: Effect of phosphorous fertilizers splitting on yield and yield components of Hashemi and Guilaneh rice cultivars and soil and plant zinc content
Author: Shahram MahmoudSoltani
Abstract: Phosphorus (P), next to nitrogen is the most important nutrients that its deficiency and low nutrient recovery cause severe nutrient disorders in world paddy fields. Therefore, to explore the effect of phosphorus fertilizer split application on morphological characters, yield, and yield component of two rice (Oryza sativa L.) cultivars (Hashemi and Guilaneh), the current experiment was conducted on a three-factor factorial experiment in a randomized complete block design with three replications. The experimental treatments were: phosphorus fertilizer split application at five levels, soil at two levels, and rice varieties at two levels. Results showed that the applied treatments positively significantly influenced almost all of the rice characters due to increasing in P availability during rice growth stages. The results also revealed that the highest increase percentage in 100- grain weight (11%) in Guilaneh, grain yield per pot (14.9%) in Guilaneh, spikelets per panicle (28.42%) tiller number and fertile tin Hashemi, Filled grain Number and unfilled grain number in Hashemi (25% and 9%0, and panicle length (3.5%0 in Hashemi variety. The results also indicated that the highest soil available P and Zn concentrations were recorded at the flowering stage about 95.3 and 90.10, and 8.6 and 8.7 mgkg-1by two and three P split for Hashemi and Guilaneh, respectively. Also, the maximum P of rice grain was obtained about 0.17 and 0.20 mgkg-1 for Hashemi and Guilaneh, respectively. The Zn content of rice grain at P split pots was significantly more than control and 100% basal application. The highest agricultural recovery (13.31 and 12.72), physiological (693.19 and 740.10) and physiological-agricultural efficiency (482.00 and 753.00), P use efficiency (5.34 and 5.66), and apparent recovery (1998 and 1272.22 kg kg-1) were found for Hashemi and Guilaneh, respectively, in the two and three P split application. Furthermore, stepwise multiple regression analysis revealed that the soil available P concentration at the ripening stage, Zn content of the grain, and Zn concentration at the rice aerial parts can explain 52% of grain yield variations for studied rice cultivars. Hence, the split application of P might be solved the low recovery of P at the paddy field and also enhance the rice grain yield.
Keywords: Rice, Hashemi cultivar, Guilaneh Cultivar, Phosphorous split application