氮素形态及供应时期对马铃薯生长发育与产量的影响

选用马铃薯克新1号和费乌瑞它2个品种，于2013-2014年在沙培条件下，研究了氮素形态及供应时间对马铃薯植株生长、块茎形成及发育的影响。结果表明，在块茎形成前供应NO₃-N与NH₄-N两种条件下，马铃薯植株高度、叶面积、叶片SPAD值、整株干物质积累量以及块茎重量无显著差异，而块茎形成后供应NH₄-N的马铃薯叶片SPAD值、植株生长速度及块茎产量均显著高于NO₃-N处理；块茎形成前供应NO₃-N的植株结薯数显著高于NH₄-N处理，但是氮素形态对干物质在马铃薯块茎中的分配比例无显著影响。因此，马铃薯的氮素养分管理应根据商品薯和种薯生产的不同目标，在块茎形成前后分别供应适宜形态的氮素。

Effects of Nitrogen Forms and Its Application Time on Plant Growth and Tuber Yield of Potato

The effects of nitrogen form on potato plant growth, tuber formation and tuber yield were studied under sand cultural condition using cultivars Kexin 1 and Favorita in 2013 and 2014. The results showed that there were no significantly different influences on plant height, leaf area, leaf SPAD value, plant dry matter accumulation and tuber weight when applied nitrite (NO₃-N) or ammonia (NH₄-N) before tuberization. However, there were higher leaf SPAD value，faster plant growth and higher tuber yield under application of NH₄-N after tuberization compared with that of NO₃-N. Moreover, no significant effect was detected on tuber dry matter distribution under different forms of nitrogen applied. Thus, potato nitrogen management including N fertilizer form and its application time should be adjusted according to the aim of commercial potato production or seed potato propagation.