Biometric Parameters and Yield Components of Wheat (Triticum aestivum) as a Function of Lime and Phosphogypsum Reapplication

The effects of lime and phosphogypsum (GY) on wheat (Triticum aestivum) nutrition are well documented. However, little is known about the influence of these soil amendments on biometric parameters or yield components. This study investigated the effects of lime and GY on wheat crops grown at cation base saturation (BS) levels of 44%, 70%, and 90%, achieved by surface application or soil incorporation of lime. Two additional treatments were included: surface liming to 70% combined with a standard rate of GY (3.71 Mg ha⁻¹) or twice the recommended GY rate (7.42 Mg ha⁻¹). The experiment was conducted during two crop seasons in Southern Brazil. The treatments did not influence dry biomass partitioning between spikes, stems, and leaves and total. In one season, liming increased flag leaf area, which was strongly associated with grain yield. Regardless of the rate, application method, and combined use of GY, liming increased the number of grains per spike in both seasons, which was the variable that most influenced wheat yield. Liming also increased spike length and the number of spikelets per spike in the 2018 season. No benefits were seen when lime was applied by soil incorporation, BS was raised to 90%, or liming was combined with GY application. The results showed a positive effect of liming on wheat yield components that are associated with grain yield.