不同播量与行距对小麦产量与辐射截获利用的影响

在田间试验条件下,设置了3个播种量(6 kg·667m 2、9 kg·667m 2和12 kg·667m 2)和3个种植行距(20 cm、25 cm和30 cm)共9个处理。通过测定小麦群体生长动态、辐射截获量和籽粒产量,研究分析不同行距和播种量对小麦产量形成和辐射利用效率的影响。结果表明:群体总茎数和叶面积指数表现为随播种量增大而增加;在相同播种量下,尽管20 cm行距的小麦分蘖数最高,但其有效成穗数却最低;叶面积指数与群体总茎数变化动态一致,而叶日积却表现为随行距和播量加大而增加。在相同播种量下,籽粒产量和辐射利用效率均随着种植行距增加呈递增趋势变化,在3个播种量下表现趋势一致。行距由20 cm增加到25 cm和30 cm,籽粒产量平均增加81.62 g·m 2和162.53 g·m 2,截获辐射利用效率平均增加0.18%和0.35%。产量和截获辐射利用率在行距间的差异均达到极显著水平,而播种量之间没有表现出显著差异,播种量和行距之间也没有明显互作效应。由此说明:调整行距对产量的影响作用大于调整播种量对产量的影响作用。因此,在水肥条件较好的黄淮海平原区小麦生产中,把传统种植行距15~20 cm调整为25~30 cm,播种量在常规播种量的基础上适量增加,可以提高小麦单产与辐射资源利用潜力。

Effects of row spacing and seeding rate on radiation use efficiency and grain yield of wheat

This study investigated the effects of row spacing (RS) and sowing rate (SR) on vegetative growth, radiation use efficiency (RUE) and grain yield of winter wheat. A field experiment was carried out in 2007 2008 at the Yucheng Comprehensive Experimental Station of Chinese Academy of Sciences, which is located in the North China Plain. The experiment included 9 treatments consisting of 3 row spacings and 3 sowing rates. The row spacings were 20 cm, 25 cm and 30 cm whereas the sowing rate were 6 kg·667m 2, 9 kg·667m^-2 and 12 kg·667m^-2. The treatments were laid out in a randomized complete block design with three replicates. Plots were 6 m long and 8 m wide and border rows were excluded from sampling to eliminate edge effects. Plant stem density, leaf area index were determined at seedling, jointing, booting, flowering, filling, milky-ripe and harvest stages, grain yield and yield compliments were determined at harvest stage. The intercepted radiation was measured from reviving to maturity stage. The results showed that row spacing had greater effect on winter wheat growth than sowing rate. Furthermore, there was no significant interaction between row spacing and sowing rate. The change trend in plant stem density varied within row spacing and was constant within sowing rates. Although the most tillers per plant was under row spacing of 20 cm, the spike rate of tillers was the least. The change in leaf area index (LAI) was the same as that in plant stem density. However, leaf area duration (LAD) increased with both widening row spacing from 20 cm to 30 cm and increasing sowing rate from 6 kg·667m^-2 to 12 kg·667m^-2. Grain yield and radiation use efficiency (RUE) increased significantly with widening row spacing under the same sowing rate, which was strongly correlated with stem density. Average grain yield increased by 81.62 g·m^-2 and 162.53 g·m^-2 as row spacing increased from 20 cm to 25 cm and 30 cm. Meanwhile average RUE increased by 0.18% and 0.35% as row spacing increased from 20 cm to 25 cm and 30 cm. Sowing rate slightly affected grain yield and RUE. Moreover, there was no obvious interaction effect of row spacing by sowing rate on grain yield and RUE. The results indicated that row spacing generally had a greater effect on wheat vegetative growth, grain yield and RUE than sowing rate. It was therefore strongly suggested to change from the conventional row spacing of 15 20 cm to the more efficient row spacing of 25 30 cm of wheat production and good field conditions in the North China Plain. Sowing rate also increased appropriately on the basis over conventional rates, which increased grain yield and RUE of wheat.