Effects of irrigation methods on yield and water use efficiency of maize in the West Liaohe Plain

Abstract: Lack of water resources restricts the modern development of Chinese agriculture and the income increase of Chinese farmers sustainably. Maize is one of the crops that need amounts of water in its whole development and growth stage. In this study, effects of different irrigation methods on yield and water use efficiency of maize in the region of West Liaohe plain were investigated. The treatments included shallow buried drip irrigation (SBDI), traditional border irrigation (TBI) and mulched drip irrigation (MDI). Dry matter accumulation and yield were measured. Transportation of dry matter and water use efficiency of maize were calculated. Two-year field contrast tests were carried out. The area of plot with 3 replicates was 864 m2 (7.2 m by120 m) respectively. The experimental cultivar was Nonghua 101 with planting density 75 000 plants /hm2. Application rate of the fertilizer was N 35 kg/hm2, P2O5 90 kg/hm2, K2O 45 kg/hm2. Additional N fertilizer of 240 kg/hm2 was applied in the jointing stage, big trumpet opening stage and silking stage according to the ratio of 3:6:1, respectively, following irrigation events. The results showed that the total amount of dry matter accumulation was the highest under condition of MDI and SBDI during 10 to 40 days after the silking stage, but both were not significantly different from TBI (P>0.05). The contribution rate of translocation rate and amount of dry matter to grain were both highest in the SBDI, followed by TBI and MDI, and the contribution rate of dry matter translocation rate to grain of SBDI was 16.7% and 5.6% higher than that of MDI and TBI respectively, and the contribution rate of amount of dry matter to grain of SBDI was 12.8% and 3.5% higher than that of MDI and TBI respectively. The differences of the dry weight of superior kennel and inferior kennel were not obvious among treatments within 30 days after silking stage, but were gradually increased after 30 days of silking. The mean grain filling rate of the superior kennel was the highest under the condition of MDI and the lowest under the condition of TBI, while inferior kennel was the highest under the condition of SBDI and the lowest under the condition of MDI. The mean grain filling rate of the superior kennel and inferior kennel were the highest in the SBDI, followed by TBI and MDI in the active growth period. The yield of SBDI was significantly higher than that of MDI, but there wasn’t significant difference with TBI in 2017. In 2018, the grain yield of SBDI was 6.1%-13.9% and 1.4%-6.2% higher than that of MDI and TBI, respectively. The change of the irrigation water use efficiency in 2017 was consistent with that in 2018, and the irrigation water use efficiency of the SBDI and MDI were both significantly (P<0.05) higher than that of TBI. In conclusion, the SBDI not only has significant advantages in saving water and promoting yield but also effectively avoids the residual film pollution due to the surface without plastic mulching, which is in favor of the SBDI to be a suitable irrigation method for high-yield and high-efficiency cultivation of maize in the irrigation region of West Liaohe plain.