施肥与品种演替对麦田CO_2排放量的影响

Effect of Fertilization and Variety Succession on CO_2 Emission of Wheat Farmland

采用田间试验与静态箱法,研究了施肥与不同年代小麦品种演替对麦田CO2排放量的影响。结果表明:(1)施肥能增大麦田土壤CO2的排放量。有机肥与适量的氮磷钾肥配合施用,促进了小麦根系的生长,增加根重和根冠比,植株生长旺盛,光合作用增强,促进了根系呼吸速率与土壤CO2的排放。不同施肥处理CO2排放量变化总趋势是:中氮处理(N1PKM)>高氮处理(N2PKM)>低氮处理(N0PKM)>空白处理(N0P0K0M)。(2)不同年代小麦品种演替影响麦田CO2的排放。根干重、根冠比、生物产量与土壤CO2的释放量呈正相关。也就是说,近期(2000年)品种山农11号生育后期根系生长旺盛,有利于碳水化合物向籽粒中转移,因而籽粒产量高,CO2的释放量亦大;早期(50年代)品种碧玛1号与之相反,生育后期根系易早衰,产量很低,CO2的释放量亦很低。总趋势是返青期与拔节期:烟农15号>山农11>碧玛1号,灌浆期:山农11号>烟农15号>碧玛1号。(3)小麦生长旺盛期(拔节期)是麦田土壤CO2排放量的最大时期。总趋势是拔节期>灌浆期>返青期。(4)土壤温度和水分对麦田CO2排放有影响。在小麦生长过程中,随地温的升高与土壤水分的增大,小麦生长旺盛,根系活性增强,加速土壤中微生物的活动和有机质的分解,同时也提高了麦田CO2的释放量。

This literary grace is tested with the static case law and the field,the wheat paddock CO2 flux of the variety changes the trends to study and apply fertilizer with various years.The result of study showed：（1） Catcher fertilization can increase soil CO2 emissions.With the appropriate amount of organic fertilizer with NPK fertilizer application for wheat root growth,root weight and increase root and coronal ratio,vigorous plant growth,photosynthesis increased,promoting root respiration rate and soil CO2 emissions.Different fertilization changes emissions of CO2 in the trend： middle concentration N treatments（N1PKM）〉low concentration N treatments（N0PKM）〉high concentration N treatments（N2PKM）〉CK concentration N treatments（N0P0K0M）.（2）Varieties succession of wheat in different years can affect the wheat field on CO2 emissions.Root dry weight,root and coronal ratio,biological yield and soil CO2 emissions were positively correlated.In other words,the recent（2000） varieties Shannong-11＇s root grow vigorous in late growing,so it is conductive to the grain carbohydrates in the transfer,thus grain yield high and CO2 emissions are large;Early（1950） on the Bima-1 in contrast,root is easy premature senility in late growing,yield low and CO2 emission is also very low.The trend is turning green in one and jointing stage： Yannong-15〉Shannong-11〉Bima-1,forming a vesicle for period： Shannong-11〉 Yannong-15〉 Bima-1.（3） Wheat growth exuberant period（jointing stage） is soil CO2 emissions in the biggest period.The trend is jointing stage〉 filling stage〉 turn green period.（4）Soil temperature and moisture affect the wheat fields of CO2 emissions.In the process of wheat growth up to the rising of the ground temperature and increase of the soil moisture,the wheat grows vigorously,the activation of the root system is strengthened,improved the release amount of wheat field CO2 at the same time.