关键词: 生态脆弱性, 胡焕庸线, 连片特困区, 经济贫困, 耦合协调度, 耦合度

Abstract: To explore the effect of soil moisture and nitrogen application rate on yield, water consumption amount and water use efficiency of spring maize, an experiment was conducted by using secondorder regression orthogonal design. Precision irrigation and fertilization was adopted in a mobile shed. The results showed that water and nitrogen coupling had a significant effect on maize yield (P<0.05). The yield increased firstly and decreased subsequently with increasing the soil moisture and the nitrogen application rate. The yield model showed that the maximum yield reached 15142.5 kg·hm^-2 when the soil moisture reached 65%-70% of field capacity and the nitrogen application rate was 462 kg·hm^-2. During the whole growth period, the water consumption amount was lowest at the earlier stage, increased slowly at the middle stage and increased rapidly at the grainfilling stage. Overall, the water consumption amount and intensity in the whole growth period increased with the increase of soil moisture. Soil moisture was the main factor influencing water use efficiency, water consumption amount and intensity, while nitrogen application rate had a weak effect.

Key words: contiguous destitute area, ecological vulnerability, coupling coordinated degree, coupling degree, Hu-Line (Hu Population Line)., economic poverty