Yan Kun, Mei Huimin, Ruan Yanan, Yu Shunyang, Su Hongyan, Zhi Yibo, Li Suxin, Sun Yanan
School of Agriculture, Ludong University, Yantai, China.
School of Life Sciences, Liaoning University, Shenyang, China.
Front Plant Sci. 2023 Oct 9;14:1225028. doi: 10.3389/fpls.2023.1225028. eCollection 2023.
A two-year field trial was conducted to investigate the effects of partial substitution of chemical fertilizer (CF) by biofertilizer (TF) on nitrogen (N) use efficiency and associated mechanisms in wolfberry () in coastal saline land. As with plant biomass and fruit yield, apparent N use efficiency and plant N accumulation were also higher with TF plus 75% CF than 100% CF, indicating that TF substitution promoted plant growth and N uptake. As a reason, TF substitution stabilized soil N supply by mitigating steep deceases in soil NH -N and NO N concentrations in the second half of growing seasons. TF substitution also increased carbon (C) fixation according to higher photosynthetic rate (Pn) and stable C abundance with TF plus 75% CF than 100% CF. Importantly, leaf N accumulation significantly and positively related with Pn, biomass, and fruit yield, and structural equation modeling also confirmed the importance of the causal relation of N accumulation coupled with C fixation for biomass and yield formation. Consequently, physiological and agronomical N use efficiencies were significantly higher with TF plus 75% CF than 100% CF. Overall, partial substitution of CF by TF improved N use efficiency in wolfberry in coastal saline land by stabilizing soil N supply and coupling N accumulation with C fixation.
进行了一项为期两年的田间试验，以研究在沿海盐碱地枸杞种植中，用生物肥料（TF）部分替代化肥（CF）对氮（N）利用效率及相关机制的影响。与植物生物量和果实产量一样，TF加75%CF处理下的表观氮利用效率和植物氮积累量也高于100%CF处理，这表明TF替代促进了植物生长和氮吸收。原因在于，TF替代通过缓解生长后期土壤铵态氮（NH₄⁺-N）和硝态氮（NO₃⁻-N）浓度的急剧下降，稳定了土壤氮供应。与100%CF相比，TF加75%CF处理具有更高的光合速率（Pn）和稳定的碳丰度，因此TF替代还增加了碳（C）固定。重要的是，叶片氮积累与Pn、生物量和果实产量显著正相关，结构方程模型也证实了氮积累与碳固定的因果关系对生物量和产量形成的重要性。因此，TF加75%CF处理的生理和农学氮利用效率显著高于100%CF处理。总体而言，TF对CF的部分替代通过稳定土壤氮供应以及使氮积累与碳固定相结合，提高了沿海盐碱地枸杞的氮利用效率。
