不同水氮运筹对冬小麦光合特性和产量的影响

Effects of Different Irrigation and Nitrogen Application on Photosynthetic Characteristics and Yield of Winter Wheat

为了确定小麦高产水肥需求规律,以周麦27为材料,研究不同水[W1(中度水分胁迫:土壤含水量为田间持水量的50%~60%)、W2(适当灌溉:土壤含水量为田间持水量的60%~70%)、W3(充分灌溉:土壤含水量为田间持水量的70%~80%)]、氮[N1(不施氮)、N2(正常施氮:225kg/hm^2)、N3(高施氮:300 kg/hm^2)]运筹对冬小麦光合特性和产量的影响。结果表明,当土壤水分含量相同时,随着施氮量的增加,小麦净光合速率(Pn)总体呈现先增加后趋于平稳的趋势,小麦旗叶SPAD值、蒸腾速率(Tr)、气孔导度(Gs)、胞间CO_2浓度(Ci)以及产量总体呈先增加后降低的趋势。当施氮量相同时,花后10 d,随着土壤含水量的增加,SPAD值总体逐渐增加(N1处理除外),Ci总体逐渐降低,Pn、Tr和Gs总体先降低后增加;花后18 d,SPAD值、Pn、Tr以及Gs总体随着土壤含水量的增加而增加,但总体上W2和W3处理间差异不显著(Gs除外);花后26 d,SPAD值随着土壤含水量的增加呈先增加后降低的趋势,Pn总体呈增加的趋势(W2和W3处理间总体差异不显著),Gs总体呈先降低后增加的趋势。当土壤水分含量相同时,与N1处理相比,N2处理小麦产量平均提高11.87%,N3处理提高了7.86%。当施氮量相同时,与W1处理相比,W2处理小麦产量平均提高3.24%,W3处理提高了2.26%。W2N2处理即施氮量为225 kg/hm^2,灌溉后土壤含水量为田间持水量的60%~70%时产量最高。说明适当的水氮运筹有利于提高小麦产量。

In order to determine the law of water and fertilizer requirement for high yield of wheat,the effects of different irrigation[W1( moderate water stress: soil water content was 50% —60% of the field capacity),W2( suitable irrigation: soil water content was 60% —70% of the field capacity),W3( full irrigation: soil water content was 70% —80% of the field capacity) ]and nitrogen[N1( no nitrogen),N2( normal nitrogen: 225 kg/ha),N3( high nitrogen: 300 kg/ha) ]application on photosynthesis and yield of winter wheat were studied with Zhoumai 27 as experiment material. The results showed that under the same soil moisture level,with the increase of nitrogen application rate,the wheat net photosynthetic rate( Pn) generally increased first and then kept steady,while the chlorophyll content( SPAD value),transpiration rate( Tr),conductance( Gs) and intercellular CO_2 mole fraction( Ci) and yield increased first and then decreased. Under the same level of nitrogen,at 10 d after the flowering,with the increase of soil moisture,the SPAD value gradually increased except N1 treatment,while Ci decreased gradually,Pn,Tr and Gs generally decreased first and then increased; at 18 d after the flowering,SPAD,Pn,Tr and Gsincreased in general,but there was no significant difference between the treatments of W2 and W3( except Gs); at 26 d after flowering,SPAD value increased first and then decreased,Pn increased( there was no significant difference between the treatments of W2 and W3),Gs decreased first and then increased.Compared with N1 treatment,the yield of wheat increased by 11. 87% for N2 treatment and 7. 86% for N3 treatment under the same soil moisture level. Under the same amount of nitrogen,compared with W1 treatment,the yield of wheat increased by 3. 24% for W2 treatment and 2. 26% for W3 treatment. In general,the yield was the highest under the W2N2 treatment( with the N of 225 kg/ha and the soil water content of 60% —70% of the field capacity). The results showed that appropriate irrigation and nitrogen application could increase the wheat yield.