覆膜与施氮互作对高粱产量及水氮利用效率的影响

为探索旱地覆膜栽培条件下适宜机械化高粱水氮利用效率,本试验于2015、2016年以机械化生产高粱品种晋杂34、晋杂35为试验材料,研究了2种栽培措施（B₁：裸地,B₂：覆膜）、3个施氮量（C₁：0kg/hm ²、C₂：225kg/hm ²、C₃：450kg/hm ²）条件对高粱不同生育期不同深度土壤贮水量、产量及水氮利用效率的影响。结果表明,覆膜有效提高了高粱不同生育期0~60cm土层土壤贮水量,但施氮水平对土壤贮水量的影响差异不明显。两年试验覆膜处理平均产量比裸地显著提高11.63%,降雨偏少年度（2015）增产12.03%,降雨偏多年度（2016）增产11.17%;不同施氮处理产量差异不显著,其与品种或覆膜方式的交互作用差异也不显著,但覆膜有效提高了氮肥利用率,尤以施氮225kg/hm ²处理氮肥偏生产力显著高于其他处理。降雨偏少年度的水分利用率、降水生产效率显著高于降雨偏多年度。与裸地处理相比,2015年覆膜处理水分利用效率提高15.93%;2016年提高12.21%。两年试验晋杂34、晋杂35都以覆膜施氮225kg/hm ²处理水分利用效果最佳,2015年表现尤为突出,水分利用效率和增产率分别为37.01、31.72kg/（mm·hm ²）和19.076%、38.286%。综合考虑,在本试验条件下,覆膜、施氮225kg/hm ²为晋杂34、晋杂35高产、水氮高效利用的最佳组合。

Interaction of Film Mulching and Nitrogen Application on Yield,Water and Nitrogen Use Efficiency of Sorghum

The purpose of our study was to explore the water and nitrogen use efficiency of mechanized sorghum under film mulching on dry land. A field experiment using Jinza No.34 and Jinza No.35 as testing materials was carried out from 2015 to 2016 to study the effects of two cultivation measures (B₁: un-mulched and B₂: film mulching) and three nitrogen levels (C₁: 0kg/hm ², C₂: 225kg/hm ², C₃: 450kg/hm ²) on soil water storage of different soil depths during the different growth periods, yield and water and nitrogen use efficiency of sorghum. The results showed that film mulching effectively improved 0-60cm soil layer water storage at different growth periods of sorghum, but there was no difference among three nitrogen levels in 0-60cm soil layer water storage. Compared to the un-mulched treatments, the grain yield was increased by 11.63% in film mulching treatments. It was increased 12.03% in 2015 and 11.17% in 2016. There was no significant difference in yield between different nitrogen levels and the interplay of nitrogen levels×varieties, nitrogen levels×film mulch method. But film mulching could effectively improve the utilization ratio of the nitrogen, the nitrogen fertilizer partial productivity of the treatments of N application of 225kg/hm ² with film mulching were significantly higher than that of the other treatments. The water use efficiency (WUE) and precipitation production efficiency in the dry year were significantly higher than that in the wet year. Compared to the un-mulched treatments, the film mulching treatment increased WUE by 15.93% in 2015 and 12.21% in 2016, respectively. The WUE of the treatments of N fertilizer application rate of 225kg/hm ² with film mulching was the highest for Jinza No.34 and Jinza No.35 in two years, and it had a better effect in the dry year with the WUE of 37.01kg/(mm?hm ²) and the yield increased by 19.076% for Jinza No.34, the WUE of 31.72kg/(mm?hm ²) and the yield increased by 38.286% for Jinza No.35. In conclusion, under the same experimental conditions, N fertilizer application rate of 225kg/ha with film mulching is the best combination of high yield and high water and nitrogen use efficiency for Jinza No.34 and Jinza No.35.