Abstract: In order to investigate the effects of different irrigation lower limit and nitrogen form ratio on the photosynthetic characteristics, yield and quality of broccoli.Two factor interaction design was adopted, among which factors were different irrigation limits and three gradients:W1 (80% water holding capacity), W2 (60% water holding capacity), W3 (40% water holding capacity);Second factor were the different ratio of nitrogen forms, and three gradients:N1(NO₃^--N:NH₄⁺-N=10:0), N2(NO₃^--N:NH₄⁺-N=7:3), N3(NO₃^--N:NH₄⁺-N=5:5). The results showed that under the same water treatment conditions,the dry weight of stem and bulb, economic yield, economic coefficient, V_C, WUE and NPP were the highest in N3 treatment.However, the contents of soluble protein, nitrate and Cu were the lowest;Under the same nitrogen ratio, the contents of dry matter weight (Except for flower ball dry weight), yield, soluble sugar, WUE and NPP in broccoli leaves increased first and then decreased with the decrease of irrigation,but the contents of soluble protein decreased in turn; Under the condition of N1 and N2, the decrease of irrigation volume significantly decreased the contents of K, Ca and Mg.Under the condition of N3, the content of Ca and Mg in broccoli treated by W2 was significantly higher than that in W1 and W3 treatments.Comprehensive analysis showed that W2N3 (lower irrigation limit 60%, NO₃^--N:NH₄⁺-N=5:5) treatment was the best combination.

Key words: Broccoli, Nitrogen form, Yield, Quality, Water use efficiency

CLC Number: 

• S143.1

• S635.01