冬小麦冠层温度及其生物学性状对施氮量的反映

在大田试验下研究了0 kg/hm2(N0)、120 kg/hm2(N120)、240 kg/hm2(N240)、360 kg/hm2(N360)四个氮肥处理对冷型小麦陕229、暖型小麦NR9405、不稳定型小麦小偃22三个品种拔节至成熟期间的冠层温度、产量及其构成因素、灌浆结实期蒸腾速率的影响及关系。结果表明:各个生育期N0冠层温度皆高于氮肥处理,随着生育期后延差异有上升趋势,在灌浆结实后期达最大。拔节期各施氮量间差异不显著;孕穗-开花期总体表现为N240处理冠层温度最低,N120和N360差异不显著;灌浆结实前期为:N360N120N240,差异在0.1~0.6℃之间,中、后期总体为N120N240N360,差异在0.1~1.5℃之间。三品种间差异也在灌浆结实后期达最大,但小麦冷暖型不随着施氮肥的增加而发生根本变化。灌浆结实各个时期蒸腾速率与冠层温度呈极显著负相关;拔节至灌浆结实期的冠层温度同理论产量皆呈极显著负相关,在灌浆结实后期相关性达最大;产量构成因素中,穗粒数、成穗数与各个时期的冠层温度均呈显著负相关,分别在拔节期和灌浆结实后期相关性达最大,千粒重与拔节期冠层温度呈极显著正相关,与孕穗期和开花期冠层温度呈显著正相关。灌浆结实中后期的冠层温度在评价小麦产量上具有较高的可靠性,可作为指导田间施氮肥的一个指标应用。

Effect of nitrogen application rate on canopy temperature and its relationship with biological characteristics of winter wheat

A field experiment was caried out to study the effect of four nitrogen treatments (N0, N120, N240 and N360) on CT(canopy temperature), yield, yield component elements and transpiration rate of three wheat varieties (Shaan229, Xiaoyan22 and NR9405) during the period from jointing to maturity. The results showed that NO CT were higher than the nitrogen treatment on each stage, and the difference was higher with the development of growth, at the late grain-filling stage filling up to the maximum. There were no significant differences among nitrogen treatments during jointing stage. N240 treatment performed the lowest CT during booting to flowering period, while N120 and N360 had no significant differences between each other. The CT was in the order of N360> N120 > N240 during early grain flling stage, and the differences were 0.1C ~0.6C. The CT was in the order of N120 > N240 > N360 during mid-late grain filling stage, and the difference were 0.1C~ 1.5C. The largest differences of CT among the three varieties were also in late grain flling stage , but the temperature type of wheat could not be changed by nitrogen fertilizations . The transpira-tion rate and CT had extremely significant negative corelation. The CT and the theoretical yield also had extremely signif-icant negative correlation from jointing to maturity, and the most extremely significance Was in late grain flling stage. The grain number per spike and spike number had negative correlation with CT in each stage, getting the largest in the joint-ing and late grain flling stage respectively. 1000 grain weight had extremely positive correlation with CT during jointing stage, and positive correlation with CT during booting and flowering stages, and the greatest relevance was in jointing stage. It is suggested that CT at mid-late grain filling stage can be used as a parameter to estimate yield and can be used as an indicator of N fertilizer application.