氮肥优化施用对花生氮素运筹、干物质积累与分配及氮肥利用率的影响

Effects of Optimized Nitrogen Application on Nitrogen Allocation, Dry Matter Accumulation and Distribution, and Nitrogen Use Efficiency in Peanut

摘要:

为探讨减氮施肥对花生氮肥利用及干物质积累及分配的影响，以吉花25为试验材料，设置0、112.5、90、78.8、159、225 kg/hm²(N0、N1、N2、N3、N4、N5)6个氮肥水平，研究不同氮肥水平对花生各部分氮含量、干物质分配及积累的影响。结果表明，减施氮肥20%(90 kg/hm²)显著提高后期花生荚果和单株氮含量，与传统施肥112.5 kg/hm²相比，减施氮肥20%饱果成熟期根干重、茎干重和果干重占总干重比例较N1分别相对提高6.52%、6.86%和5.89%，叶干重占总干重的比例相对降低8.09%；果干物重提高4.02%，总干物重提高0.55%。氮肥施用量在90 kg/hm²时，有利于提高花生氮肥利用效率，生育中后期促进干物质向荚果分配，显著提高氮农学效率和氮偏生产力。综合考虑干物质分配、氮肥利用效率和产量，最适施氮量为纯氮90 kg/hm²。

Abstract:

To investigate the effects of reduced nitrogen application on nitrogen allocation, dry matter accumulation and distribution, and nitrogen use efficiency in peanut, peanut cultivar‘Jihua 25’was used as the experimental material. Six nitrogen application rates 0, 112.5, 90, 78.8, 159 and 225 kg/ha were tested and designated N0, N1, N2, N3, N4 and N5, respectively. The effects of nitrogen application rate on nitrogen concentrations in different plant organs, dry matter accumulation and dry matter distribution were evaluated. The results showed that a 20% reduction in nitrogen application, corresponding to 90 kg/ha, significantly increased nitrogen concentrations in pods and whole plants during the late growth stage. Compared with the conventional nitrogen application rate of 112.5 kg/ha, the 20% reduction in nitrogen application increased the proportions of root, stem and pod dry weight to total dry weight at the pod-filling maturity stage by 6.52%, 6.86%, and 5.89%, respectively, while the proportion of leaf dry weight to total dry weight decreased by 8.09%. Pod dry weight and total dry weight increased by 4.02% and 0.55%, respectively. Applying 90 kg/ha improved nitrogen use efficiency, promoted dry matter allocation to pods during the middle and late growth stages, and significantly increased agronomic nitrogen-use efficiency and nitrogen partial factor productivity. Considering dry matter distribution, nitrogen use efficiency and yield, the optimal nitrogen application rate under the conditions of this experiment was 90 kg/ha.