Date of this Version
Li, J., W. Zang, Y. Li, D. M. Heeren, and H. Yan. 2018. Comparison of nitrogen fertigation management strategies for center-pivot irrigated maize in the sub-humid area of China. ASABE Annual International Meeting, Paper No. 1801036, Detroit, Mich. 9 pages.
In the sub-humid region of Northeast China, increasing use of center-pivot irrigation systems has caused increased interest in sprinkler fertigation technology in maize production to improve nitrogen (N) use efficiency and protect the environment. However, the lack of fertigation strategies for maize cultivation restrains the adoption of sprinkler fertigation technology. A field experiment was carried out in a sub-humid region of Northeast China on maize to determine the effect of different fertigation management strategies on plant growth, grain yield and nitrate content in the soil during the maize growing season. Three N rates (200, 160, and 120 kg N ha-1) and three fertigation schedules were tested. After a uniform nitrogen fertilizer application at an early stage, the N treatments applied 100% of the remaining amount of fertilizer at the stage of vegetative (V) 14 (T1); applied 66.7% and 33.3% of the remaining amount of fertilizer at the stage of V14 and reproductive 2 (R2), respectively (T2); and applied 75% and 25% of the remaining amount of fertilizer at the stage of V14 and R2, respectively (T3). The N rates and fertigation schedules were combined to make nine treatments: T1N200, T1N160, T1N120, T2N200, T2N160, T2N120, T3N200, T3N160, and T3N120, each having three replications. Full irrigation was applied in order to minimize water stress. All treatments received the same irrigation depth in each fertigation event. Results showed that maize grain yield and above-ground biomass production increased with the increasing of N rates; N200T1 produced a higher yield (12,710 kg ha-1) than the other fertigation treatments. However, there was no significant difference in yield between the N rates of 160 and 200 kg ha-1(P＜0.05), while partial factor productivity decreased with increased N application. Furthermore, the amount of the mineral nitrogen (NO3–N) accumulated in the 0- to 100-cm layer after harvest increased as the N rates increased. At the high N level, the residual NO3–N in the soil in T1 was 65% and 51% less than that in T2 and T3, which decreased the risk of NO3–N leaching out of the 0- to 100-cm soil layer. Based on this research, the recommended management practice of fertigation via center-pivot irrigation systems is to apply 160 kg ha-1 of nitrogen (N160) to maize through two in-season fertigation events (T1), which can obtain relatively high production, meanwhile reducing the risk of nitrogen leaching in the sub-humid region of China.