Effects of water and nitrogen coulping on growth and development of Zizphus jujuba ‘Tongxinyuanzao’ under infiltration irrigation

  Objective  This paper aims to explore the changes of various factors of Zizphus jujuba ‘Tongxinyuanzao’ in arid area under different water and fertilizer coupling treatments, and clarify the effects of different water and fertilizer coupling on promoting Z. jujuba ‘Tongxinyuanzao’ growth and development.

  Method  In this study, 8-year-old Z. jujuba ‘Tongxinyuanzao’ was selected as the research object, different irrigation quotas (W1: 2 250 m³/ha; W2: 3 000 m³/ha; W3: 3 750 m³/ha) + nitrogen application rate (N1: 240 kg/ha; N2: 300 kg/ha; N3: 360 kg/ha) 2-factor 3-level test was set, so as to analyze the effects of water and nitrogen coulping with underground infiltration irrigation on jujube leaf chlorophyll content (SPAD) and nitrogen content (C_N), yield, water use efficiency (WUE), partial factor productivity of nitrogen (PFP).

  Result  The irrigation had significant effect on the leaf SPAD and N content of Z. jujuba, but the nitrogen application had no significant effect on the leaf SPAD and N content. With the increase of irrigation application and nitrogen, the general trend of leaf SPAD and N content of Zizphus jujuba was firstly increased and then decreased; W2N3 treatment had the highest leaf SPAD and N content. The coupling of water and fertilizer had a significant impact on the mass of single fruit, number of fruits per plant, yield, water use efficiency and partial factor productivity of nitrogen. With the increase of irrigation and nitrogen application, it first increased and then decreased. The W2N2 treatment had the highest water use efficiency (2.54 kg/m³), the highest partial factor productivity of nitrogen (24.15 kg/kg), thehighest yield (7 246.26 kg/ha), which was significantly different from other treatments (P < 0.05).

  Conclusion  The results of this study show that the suitable interaction of water and nitrogen (W2N2) was beneficial to increase the yield of Z. jujuba ‘Tongxinyuanzao’ and achieve ideal water use efficiency and partial nitrogen fertilizer productivity. It has a positive effect on the growth and development of Z. jujuba ‘Tongxinyuanzao’.