Abstract:

This research aimed to provide scientific and technical data to support high-yield and high-efficiency of maize cultivation in the arid region of Ningxia and investigated the effects of potassium application rates on dry matter accumulation， transport， and yield formation of maize （Zea mays） under drip irrigation. A randomized block trial was conducted in 2022 and 2023 at Pingjipu Farm， Yinchuan， Ningxia， China. The trial included six potassium fertilizer treatments： 0 （K₀）， 60 （K₁）， 120 （K₂）， 180 （K₃）， 240 （K₄）， and 300 kg·ha^-1 （K₅）. Appropriate potassium supplementation significantly enhanced dry matter accumulation and improved both pre- and post-anthesis substrate translocation efficiency， thereby establishing the foundation for yield improvement. The K₃ treatment achieved maximum dry matter accumulation of 37826 kg·ha^-1 in 2022 and 36610 kg·ha^-1 in 2023. These values significantly exceeded those of other treatments by 6.53%-23.12% and 3.62%-18.79%， respectively. The pre-anthesis dry matter translocation contribution rate under the K₃ treatment was 14.84%-81.87% （2022） and 5.61%-25.84% （2023） higher than other treatments. Post-anthesis dry matter accumulation in K₃ increased by 7.13%-17.44% （P<0.05） and 1.48%-16.33% across the two years. Compared with K₀， K₃ exhibited 20.63% （2022） and 18.47% （2023） higher biomass at maximum biomass accumulation. The maximum dry matter accumulation rate under K₃ surpassed other treatments by 4.42%-37.21% （2022） and 1.52%-18.24% （2023）， while the mean accumulation rate increased by 6.60%-40.50% and 4.25%-22.74%， in 2022 and 2023， respectively. The K₃ treatment also achieved the highest mean crop growth rate （CGR）， exceeding other treatments by 4.75%-26.36% and 2.93%-17.16% in 2022 and 2023， respectively. Maize yield initially increased then decreased with increasing potassium application rates， peaking under K₃ at 15179 kg·ha^-1 （2022） and 14944 kg·ha^-1 （2023）， corresponding to average yield improvements of 2.29%-18.07% and 4.32%-28.24%， respectively， over other treatments. Path analysis revealed that under high-density planting conditions， prioritizing enhancement of 100-grain weight， followed by ear number and kernel number per ear could further boost yields. Quadratic regression analysis identified optimal economic potassium rates of 167.25 kg·ha^-1 （2022） and 170.66 kg·ha^-1 （2023）. Integrated analysis therefore demonstrates that the recommended optimal economic potassium application rate for maize in arid regions of Ningxia ranges from 167 to 180 kg·ha^-1， thereby achieving the dual objectives of high-yield and resource-efficient cultivation.

Key words: arid region, maize, potassium fertilizer, dry matter, yield