Abstract: A field experiment was conducted to study characteristics and regularity of nutrient uptake and accumulation of dry matter of greenhouse vegetable under micro-sprinkling irrigation and their relationship. Results show that N, P and K contents in the plant varied sharply with the plant growing stage. The plant in the prime vegetative growth stage was much higher in nitrogen, phosphorus and potassium content than that in the seedling stage. However, contents of the nutrients declined slightly after the plant entered its maturing stage. As far as nutrient absorption rate was concerned, the prime vegetative growth stage was the highest for all the three nutrients and then the seedling stage and maturing stage, and the three nutrients followed an order of potassium ＞ nitrogen ＞ phosphorus. In terms of nutrient and dry matter accumulation, the three growing stages followed an order of prime vegetative growth stage ＞ seedling stage ＞ maturing stage. In addition, correlation analysis shows that plant dry matter accumulation was significantly and positively related to nutrient uptake. Under optimized coupling of water-fertilizer, positive relationships were found between the three nutrients mutually promoting each other in absorption.

Key words: greenhouse vegetable, micro sprinkler irrigation, water and fertilizer coupling, nutrient uptake