Rice (Oryza sativa L.) Growth and Yield Responses to Yara Fertilizer Formulations in Rain-fed Lowland Condition

This experiment evaluated the effects of Unik-15 (15N + 15P + 15K) and Actyva (23N + 10P + 5K+ 2MgO+ 3S + 0.3Zn), likewise Amidas(40N+5.6S) and urea (46N) on rice growth and yield under rain-fed lowland condition. The study was a single factor trial laid out in a Randomized Complete Block (RCB) design with three replications at the University for Development Studies Experimental Field, located in Tamale, Ghana. The treatments were inorganic fertilizer combinations with a control (T1 = UNIK- 15 at 125 kg ha-1 + AMI at 125 kg ha-1, T2 = ACT at 125 kg ha-1 +AMI at 125 kg ha-1; T3 = UNIK-15 at 125 kg ha-1 + URE at 125 kg ha-1, and T4 = ACT at 125 kg ha-1 +URE at 125 kg ha-1). The Growth and yield traits measured were tiller number, plant height, number of grains panicle-1, panicle length, grain yield, and 1000-grain weight. The results showed that the fertilizer treatments significantly (P<.05) influenced growth and yield parameters. The application of UNIK-15 at 125 kg ha-1+URE at 125 kg ha-1 resulted in the tallest plant (115.26 cm), longest panicle (29.30 cm), highest grain yield (6,074 kg ha-1) and maximum 1000-grain weight (23.72 g). The number of tillers were increased by 53, 66, 74 and 81% for ACT+AMI < UNIK-15+AMI < ACT+URE < UNIK- 15+URE over the control, respectively. Similarly, ACT+AMI < ACT+URE < UNIK-15+AMI < UNIK-15+URE produced more grains panicle-1 than the control, increasing it by 46, 51, 78, and 91%, respectively. Likewise, the grain yield was increased by 99, 132, and 178%, respectively, compared to the control, by ACT+AMI < ACT+URE < UNIK-15+AMI. Grain yield positively correlated with effective tiller count (r=0.53*), number of grains per panicle (r=0.90***), and 1000- grain weight (r=0.80**). Therefore, the application of UNIK-15 at 125 kg ha-1 + URE at 125 kg ha- 1 is recommended for rice production under lowland condition.