间作对不同氮水平下小麦产量优势形成的影响

Effect of Intercropping on Yield Advantage Formation of Wheat under Different Nitrogen Levels

为探明间作小麦的产量特征,通过2 a田间试验研究了小麦蚕豆间作种植对不同氮水平(N0、N1、N2、N3施氮量分别为0,90,180,270 kg/hm^2)下小麦产量及地上部干物质累积量的影响,并用Logistic模型模拟了单间作小麦的关键生长参数(最大生物量(A)、初始生长速率(r)、最大生长速率(Rmax)和达到最大生长速率的时间(Tmax))及生长动态。结果表明,小麦蚕豆间作产量优势明显,LER>1(除N3水平外)。小麦产量和关键生长参数均受间作和施氮量的影响。除N3水平外,与单作小麦(MW)相比,间作平均提高靠近蚕豆的间作第1行小麦(IW1)的产量29.5%、Rmax 24.4%(除2017年N0外)、r 16.1%(除2017年N0外);N1~N2水平下,间作还平均提高IW1的A 7.9%。此外,间作也提高了小麦生长高峰期的生长速率,增加了IW1在生殖生长阶段(播种90~180 d)地上部生物量。同时,间作还使N0~N2水平下距离蚕豆稍远的第2行小麦(IW2)的产量(除2018年N2外)增长19.7%;提高N1、N2(除2018年N2外)的A 7.8%和Rmax 10.6%。综上所述,小麦蚕豆间作产量优势的形成源于边行优势和内行积极效应;间作显著提高边行和内行小麦关键生长参数A、Rmax和r是产量优势形成的基础。但间作优势和内行效应随氮肥投入量的增加而降低甚至消失。研究结果为合理间作及间作体系氮肥的合理施用提供依据。

Two years field trials were conducted to study the effects of wheat and faba bean intercropping on wheat yield and dry matter accumulation under different nitrogen(N)levels the application rate for N0,N1,N2,and N3 was 0,90,180 and 270 kg/ha,respectively.Logistic model was used to simulate the key growth parameters including the maximum biomass(A),initial growth rate(r),the maximum growth rate(Rmax),time to reach the maximum growth rate(Tmax)and growth dynamics for inter-and mono-cropped wheat.The results showed that the yield advantage of wheat and faba bean intercropping was significant,LER>1(except for N3).Both wheat yield and key growth parameters were affected by intercropping and N application rates.Except for N3 level,compared with monocropped wheat(MW),wheat and faba bean intercropping averagely increased the yield,Rmax and r of the first row of intercropping wheat(IW1)(next to faba bean in a intercropping pattern)by 29.5%,24.4%(except for N0 level in 2017)and 16.1%(except for N0 level in 2017),respectively.Under N1 and N2 levels,the A of IW1 was averagely increased by 7.9%as compared to MW.The growth rate of IW1 was also improved when wheat intercropped with faba bean relative to corresponding MW during wheat attained its growth peak and resulted in stimulated biomass accumulation during reproductive growth stages(90-180 days after sowing).The yield of the second row of intercropping wheat(IW2)(slightly far away from faba bean in a intercropping pattern)was increased by 19.7%(except 2018 N2)when compared to MW under N1 to N2 levels.Under N1 and N2 levels,both the A and Rmax for IW2 were averagely increased by 7.8%and 10.6%(except 2018 N2)relative to MW,respectively.In conclusion,the formation of wheat and faba bean intercropping yield advantages originated from the border row advantage and the positive effect of inner-row.The key growth parameters of A,Rmax and r played an important role in intercropping yield advantages.However,the intercropping advantage decreased or even disappeared with the increased N rates.It is imperative for rational intercropping and rational application of N fertilizer in intercropping system.