节水条件下供氮水平对冬小麦氮素吸收利用特性的影响

为给小麦水氮高效栽培提供依据，以高水肥品种保麦10和抗旱品种石麦22为材料，研究了春季节水条件下高氮（施N 225 kg·hm^-2）、低氮（施N 112.5 kg·hm^-2）处理的小麦植株氮素吸收利用特性。结果表明，与低氮处理相比，高氮处理下小麦各生育时期的植株氮累积量增多，累积强度增大。小麦成熟期籽粒、茎秆、叶片和颖壳的氮累积量、花前氮转运量和籽粒产量随着施氮水平的提高而增加。高氮处理下，品种间各生育时期、阶段氮累积数量、吸收强度、氮利用特征参数和产量无明显差异；低氮处理下，与保麦10相比，石麦22各生育时期、阶段的氮累积量、氮素累积强度、氮收获指数、花前氮转运量、花前氮转运率和氮肥偏生产力均不同程度增高，且差异多达显著水平。这说明小麦对低氮供应的响应特征在品种间存在较大差异。其中，抗旱小麦品种石麦22节水低氮栽培下具有较强的氮素吸收和转运能力，这可能是该类别小麦品种抗旱高产的重要生理基础。

Effect of Nitrogen Application Level on Acquisition and Utilization of N under the Water-Saving Cultivation Conditions in Winter Wheat

In order to provide scientific basis for high water and nitrogen use efficiency in wheat cultivation, using Baomai 10 and Shimai 22, two wheat cultivars suitably planted under the affluent water as well as fertilizer conditions and the water saving conditions, respectively, the effects of nitrogen(N) application level together with reduced irrigation on N acquisition and utilization, at the key growth and development stages were investigated. Under the sufficient-N conditions, the plants exhibited increased N accumulative amounts and accumulation rates, at all growth stages, showing the elevated N accumulative amounts in grain, stem, leaf and glume at maturity stage. the enhanced transportation amounts derived from pre-flowering N, and the increased yields compared with those under the deficient-N conditions. In addition, Baomai 10 and Shimai 22 both displayed similar N accumulative amounts and comparable N accumulation rates at different growth stages, and comparable N utilization associated parameters and yields under the sufficient-N conditions. However, under the deficient-N treatments, compared with Baoming 10, Shimai 22 showed increased N accumulative amounts, enhanced N accumulation rates, elevated N utilization parameters, such as increased N harvest index, transportation amounts of pre-flowering stored N, translocation rates of pre-flowering stored N, and partial productivity of the N fertilizer. Among these N utilization-associated traits, most of them were shown to be significant difference. The results in this study suggest that the cultivars examined possess drastic variation in response to the external N application input. Compared with Baomai 10, Shimai 22 has relatively strong capacity in N acquisition and possesses improved efficiency in using and transferring N from the vegetative tissues to the harvest organ. Our investigation indicates that the drought-tolerant cultivar, such as Shimai 22, has strong capacity of N acquisition and utilization than the drought-sensitive cultivar Baomia 10. which contributes to the relatively high productivity of wheat drought-tolerant cultivar challenged by the drought stress.