不同灌水量下喷施腐植酸对燕麦光合特性及产量的影响

研究旨在明确不同灌水量下喷施腐植酸对燕麦光合特性及产量的影响。在防雨棚池栽条件下,以蒙农大燕1号为试验材料,在3种不同灌水量（60、120和180mm）处理下,于孕穗期和开花期分别在叶面喷施腐植酸（HA）和等量清水（WT）,CK为不喷施处理,分析测定燕麦植株形态、光合参数及产量构成因素等指标。结果表明,在60mm和120mm灌水量下,HA处理的株高、单株叶面积、气孔导度（G_s）、净光合速率（P_n）和蒸腾速率（T_r）均显著提高（P<0.05）,胞间CO₂浓度（C_i）降低,60mm灌水量下各指标增幅高于120mm灌水量;P_n平均分别提高了43.4%和36.3%,单株叶面积平均分别提高了54.3%和34.7%（P<0.05）;与CK相比,喷施HA后籽粒产量显著提高,60mm和120mm灌水量下增产率分别达22.7%和18.0%,穗长和单穗粒数均显著增加（P<0.05）;而WT处理对植株形态、光合参数和产量等指标无显著影响。180mm灌水量,HA处理P_n和单株叶面积较CK和WT显著增加,籽粒产量提高幅度不显著。综上,在较低灌水量下喷施腐植酸可以改善燕麦光合能力,促进籽粒灌浆并提高籽粒产量。

Effects of Different Irrigation Amounts and Spraying Humic Acid on Photosynthetic Characteristics and Yield of Oat

The purpose of the study was to clarify the effects of spraying humic acid on the photosynthetic characteristics and yield of oats under different irrigation amounts.Under the condition of rain-proof shed pond cultivation,using Mengnongdayan No.1 as the test material,three different irrigation amounts(60,120 and 180mm),and three spraying treatments of spraying humic acid(HA),spraying water(WT)and no spraying(CK)at booting stage and flowering stage were set to analysis and determine the plant morphology,photosynthetic parameters,yield components,and other indicators.The results showed that under 60mm and 120mm irrigation rates,HA treatment significantly increased plant height,leaf area per plant,stomatal conductance(Gs),net photosynthetic rate(Pn),and transpiration rate(Tr)(P<0.05).The CO2 concentration(Ci)decreased,the increase of each index under 60mm irrigation amount was higher than that of 120mm;Pn increased by 43.4%and 36.3%on average,leaf area per plant increased by 54.3%and 34.7%on average(P<0.05);Grain yield of HA treatment significantly increased under 60mm and 120mm irrigation amounts by 22.7%and 18.0%,respectively.Ear length and grain number per panicle increased significantly(P<0.05);while WT treatment had no significant effects on morphology,photosynthetic parameters,yield and other indicators.With an irrigation amount of 180mm,the photosynthetic rate and leaf area per plant under HA treatment were significantly increased compared with CK and WT,and the increase of grain yield was not significant.In summary,spraying humic acid under low irrigation can improve the photosynthetic capacity of oat,thereby promoting grain filling and increasing grain yield.