“…The study also developed a direct formula to estimate optimal fertilizer rates that maximize expected returns. The LRSP function has been used extensively to model crop yields to fertilizers in cotton, wheat, forage, corn, potatoes, and sorghum (Asci, Borisova, and VanSickle, 2015;Biermacher et al, 2009;Boyer et al, 2013Boyer et al, , 2015Brorsen and Richter, 2012;Harmon et al, 2016;Kaitibie et al, 2003Kaitibie et al, , 2007Tumusiime et al, 2011;Zhou et al, 2015).…”