Nitrate leaching from applied fertilizer is reduced by precision nitrogen management in baby corn cropping systems
Nitrate leaching from applied fertilizer is reduced by precision nitrogen management in baby corn cropping systems
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DOI：
10.1007/s10705-021-10156-3
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发表时间：
2021-06
影响因子：
3.1
通讯作者：
Varinderpal-Singh;N. Kaur;Kunal;Blestar-Singh;J. Kumar;Aman Thapar;E. Ober
中科院分区：
文献类型：
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作者：
Varinderpal-Singh;N. Kaur;Kunal;Blestar-Singh;J. Kumar;Aman Thapar;E. Ober
对连续三个幼玉米（Zea maysL.）生长季节，以量化的反应性N流超出根际，同时定义缓解策略的量。根据作物需要施氮比定时覆盖施氮在农艺上更有效。平均面积尺度的渗滤液氮损失在冬季分别比夏季和春季高24%和8%。在低氮水平下，较小的根系可能会限制植物对氮的吸收，并加速不同季节氮素淋失系数的大小，范围为6 - 9%。渗滤液氮通量的峰值在生长初期更为明显，这是由于氮供应超过了植物的需要。残留的土壤矿质氮变化不大，尽管范围广泛的肥料氮率，因此没有证据支持的想法，土壤应补充氮去除作物在固定的生长阶段。相反，氮损失到环境中更大的使用固定时间毯N的应用程序，这可以减轻转移到N施肥的基础上评估植物的需要。使用PAU叶色图和叶绿素计指导需求型肥料氮追肥，与毯式氮肥使用实践相比，平均渗滤液NO3 <$-N负荷减少了69%，同时使幼嫩玉米的穗轴产量平均提高了17%。因此，毯式氮肥使用的做法，应取代需求为基础的氮管理策略，以减轻环境足迹的婴儿玉米为基础的种植系统中的N使用。
In-situ field studies were conducted for three consecutive baby corn (Zea maysL.) growing seasons to quantify the amount of reactive N flowing beyond the rhizosphere while defining mitigation strategies. The N applications based on plant need were agronomically more efficient than the fixed-time blanket N applications. Average area-scaled leachate N losses in the winter season were 24 and 8% higher than the summer and spring seasons, respectively. A smaller root system at low N rate likely restricts plant N uptake and accelerates the magnitude of N leaching factor ranging from 6 to 9% in different seasons. Leachate N-flux peaks were more pronounced at early growth stages, attributed to the N supply in excess of the plant need. Residual soil mineral N varied little despite a wide range of fertilizer N rates, hence there was no evidence to support the idea that soils should be replenished for N removal by crops at fixed growth stages. Rather, N losses to the environment were greater using fixed-timing blanket N applications, which can be mitigated by a shift to N fertilization based on assessment of plant need. Use of the PAU-leaf colour chart and chlorophyll meter to guide need-based fertilizer N topdressings reduced average leachate NO3¯-N load by 69% over blanket N use practice, while producing an average 17% higher cob yield in baby corn. Hence, the blanket N use practices should be replaced with need-based N management strategies to mitigate environmental footprints of N use in the baby corn based cropping system.