改变玉米行距种植对豌豆/玉米间作体系产量的影响

间作体系中改变作物的种植行距可改变体系作物的种间互作效应,影响作物产量。本研究通过设置豌豆/玉米间作种植体系中玉米的5种种植行距(0 cm、20 cm、40 cm、60 cm和80 cm),以期揭示间作体系中作物种植行距变化对体系作物产量的影响。结果表明:豌豆/玉米间作体系产量优势明显,各处理的土地当量比均大于1。玉米种植行距在0~80 cm区间改变时对体系产量的影响总体表现为随玉米行距增大,产量先增后降,且玉米种植行距与体系混合产量和间作玉米产量均呈现二次曲线相关关系,产量峰值出现在玉米种植行距为40 cm时,间作玉米产量达10 118 kg.hm 2。玉米行距变化对豌豆产量的影响不明显,间作体系产量主要受间作玉米产量影响。改变玉米行距种植明显改变了玉米的产量性状,主要表现在穗粒数上,行距为60 cm时,穗粒数最大,达549粒。种间相对竞争力总体表现为随玉米行距的增大玉米相对于豌豆在产量形成方面的竞争力逐渐增强;在玉米行距0~60 cm之间,豌豆相对于玉米的种间相对竞争力均<0,表明竞争力玉米强于豌豆,而当玉米行距为80 cm时,种间竞争力为0.14,表明此时豌豆竞争力强于玉米。因此,通过合理调整玉米种植行距从而提高间作玉米产量有利于提高豌豆/玉米间作体系的整体产量。

Effect of maize row spacing on yield of pea/maize intercropping system

Crop row spacing in intercropping systems affects interactions of crop species and subsequent crop yields. In a field experiment, the response of crop yield to different maize row spacing (0~80 cm) in pea/maize intercropping system was investigated. The results showed that land equivalent ratio (LER) of each treatment exceeded 1, indicating a significant yield advantage. When maize row spacing changed from 0 cm to 80 cm, the system yield first increased to a threshold and then declined. Positive quadratic relations between maize row spacing and yields of intercropping system or intercropped maize were observed in the field experiment. The highest yield occurred when maize row spacing was 40 cm and intercropped maize yield reached 10 118 kg·hm^-2. Since intercropped pea yield never changed significantly, yield of the intercropped pea/maize system was dependent on maize yield. The change in maize row spacing significantly influenced maize yield components and especially grain number per spike. Grain number per spike (549 grains per spike) was highest when maize row spacing was 60 cm. Maize aggressive dominance over pea in terms of yield gradually strengthened with increasing maize row spacing. When maize row spacing was within 60 cm, its aggressive dominance over pea was below zero. This indicated that maize had a stronger competitiveness than peas. However, when maize row spacing was 80 cm, its relative aggressive dominance was 0.14 - which suggested that pea was more competitive than maize. Hence adjustment of maize row spacing effectively enhanced maize yield in pea/maize intercropping system. This increased production output of pea/maize intercropping system.