Development of critical shoot and root N curves for diagnosing sweetpotato shoot and root N status
Development of critical shoot and root N curves for diagnosing sweetpotato shoot and root N status
复制标题
制定用于诊断甘薯地上部和根氮状态的临界地上部和根氮曲线
DOI：
10.1016/j.fcr.2020.107927
复制
发表时间：
2020-10-15
影响因子：
5.8
通讯作者：
Lu Guoquan
中科院分区：
文献类型：
--
作者：
Lv Zunfu;He Weichen;Lu Guoquan
甘薯还没有建立用于诊断作物季节氮素状况的临界氮(N)曲线。此外，对临界根N曲线的研究也很少。以甘薯地上部(SDM)、根部(RDM)和植株(Pdm)干物质为基础，确定了3条新的甘薯氮素营养临界曲线，以评价甘薯氮素营养状况。以新乡和商19两个甘薯品种为试材，进行了3个不同施氮量(0~180 kg N ha~(-1))的田间试验，分析了甘薯干物质与氮素浓度的关系，建立了甘薯氮素临界浓度模型。甘薯SDM(N-S)的临界地上部N可用方程N-S=5.14SDM-0.661(SDM>=1.7tha(-1))来描述，对于SDM<；1.7tha(-1)，采用一个恒定的临界值(N-S=3.68)。甘薯的临界根N可用方程式N-r=0.57RDm-0.425来描述。甘薯基于产品数据管理的临界植株N(N-p)可用公式N-p=3.52Pdm-0.486来描述。该曲线能有效区分不同环境条件下的限氮和非限氮处理。不同施氮量处理的地上部N营养指数(NNIs)、根N营养指数(NNIr)和植株N营养指数(NNIP)分别为0.39~1.28、0.31~1.32和0.36~1.36。NNIr随植株生长呈增加趋势，NNIs和NNIP随植株生长呈下降趋势。这些结果为指导甘薯关键生育期氮素营养状况诊断提供了准确的工具，有助于指导中国甘薯集约化种植制度的可持续发展。
No critical nitrogen (N) curve, used for diagnosing the in-season N status of crop plants, has been constructed for sweetpotato. Moreover, the critical root N curve has rarely been studied. This study determined three new critical N curves based on shoot (SDM), root (RDM), and plant (PDM) dry matter to assess N nutrition in sweetpotato in China. Three field experiments were conducted with varying N application rates (0-180 kg N ha(-1)) using two sweetpotato cultivars, Xinxiang and Shang 19. The relationship between dry matter and N concentration was analysed, and a model of critical N concentration for sweetpotato was constructed. Critical shoot N for sweetpotato based on SDM (N-s) is described by the equation N-s = 5.14 SDM-0.661 (SDM >= 1.7 t ha(-1)); for SDM < 1.7 t ha(-1), a constant critical value (N-s = 3.68) is applied. The critical root N for sweetpotato based on RDM (N-r) is described by the equation N-r = 0.57 RDM-0.425. The critical plant N for sweetpotato based on PDM (N-p) is described by the equation N-p = 3.52 PDM-0.486 . The curves can effectively distinguish N-limiting from non-N-limiting treatments under different environmental conditions. In the present study, the shoot N nutrition index (NNIs), the root N nutrition index (NNIr) and the plant N nutrition index (NNIp) ranged from 0.39 to 1.28, 0.31 to 1.32 and 0.36 to 1.36 under different N rate treatments, respectively. The NNIr tended to increase with plant growth, while the NNIs and NNIp tended to decrease with plant growth. These results provide an accurate N status diagnosis tool at critical growth stages to guide the balance of source and sink in sweetpotato, contributing toward the sustainability of intensive sweetpotato cropping systems in China.