摘要
针对禾豆间作协同利用化学氮肥和豆科固氮潜力调控依据薄弱问题,以河西走廊区主导间作模式玉米/豌豆间作系统为研究对象,研究了禾豆间作间距为15 cm、30 cm和45 cm空间结构对间作豌豆氮阻遏减缓效应的影响,以期为禾豆间作种植模式优化空间结构、减缓氮阻遏、提高氮素利用效率提供理论依据。2013和2014两年研究结果表明,与单作相比,间作豌豆有效根瘤个数和根瘤重均有显著提高,根瘤数提高幅度达0~500%,其中间距为30 cm时,豌豆的根瘤数和瘤重达最大。以根瘤数和根瘤重计算的氮阻遏消减效应(Ca)均为正值,施氮条件下,玉米与豌豆间距为30 cm处理的氮阻遏消减效应显著高于15 cm和45 cm间距处理,2013年和2014年以根瘤数计算的Ca值分别达78.70%和161.21%,说明间作相对于单作都具有减缓氮阻遏的作用。而在此期豌豆的营养竞争比率(CRpm)大于1,豌豆相对于玉米具有较强的种间竞争能力。禾豆间作可显著提高氮素利用效率,以间距为30 cm的间作处理最高,2013年和2014年两年平均较间距为15 cm和45 cm空间结构的间作模式分别提高21.90%和21.88%。说明优化空间结构可有效增加间作豌豆的结瘤数和瘤重,增强氮阻遏减缓效应,调控禾豆间作系统氮素吸收利用,提高氮素利用效率。
Optimization of spatial structure in intercropping system is important for increasing crop yield and improving resource utilization efficiency. However, the theoretical basis for improving nitrogen fixation functions of legume and nitrogen utilization efficiency by optimizing the spatial structure of intercropping system has not been well investigated. Thus the synergistic effect of legume/cereal intercropping system on nitrogen nutrient utilization and regulation potential of legume plants was investigated in a field experiment on pea/maize intercropping system in the Hexi Corridor. The experiment consisted of monoculture pea, monoculture maize and pea/maize intercropping systems. In intercropping system, three intercropping spacings between pea and maize were set, which were 15 cm, 30 cm and 45 cm, with unchanged pea row spacing and changed maize row spacing; two nitrogen application rates were also set for intercropped maize, 0 kg?hm-2 and 260 kg?hm-2. The aim of the experiment was to determine the effect of spatial structure of pea/maize intercropping system on alleviation of "nitrogen inhibition"(N inhibition) on pea nodulation caused by N fertilization. The results of the study also provided a much better understanding of the optimization of the spatial structure of legume/cereal intercropping system, and the improvement of N use efficiency. The results for 2013–2014 showed that pea/maize intercropping significantly increased nodule number and weight of pea, compared with single-cropping pea system. Increase in nodule number varied from 0 to 500%, with the largest nodule number and weight appearing under intercropped spacing of 30 cm. N inhibitory effects(Ca) calculated by using nodule number and weight were all positive. Under N application, the effect on alleviating "N inhibition" under 30 cm spacing was significantly higher than that under 15 cm and 45 cm intercropping spacings. With N application, Ca calculated from nodule number reached 78.70% and 161.21% in both 2013 and 2014 growing seasons, and Ca calculated from nodule weight reached 154.87% and 406.52% without N fertilization. The ratio of nutrient competition of pea plants(CRpm) was greater than 1, which suggested that the capacity of interspecific competition of pea was higher than maize. Intercropping system significantly improved N use efficiency and N use efficiency under 30 cm spacing was significantly higher than that under 15 cm and 45 cm intercropping spacings. N use efficiency under spacing of 30 cm was average 21.90% and 21.88% higher than that of 15 cm and 45 cm respectively in 2013 and 2014 growing seasons. The optimization of spatial structure in intercropping increased nodule number and weight of pea plants, alleviated "N inhibitory effect", regulated N uptake effect and enhanced N use efficiency of pea/maize intercropping system. The results of this study were critical for developing N-saving intercropping systems, enriching the theory of N use efficiency and improving the contribution of N fixation of legume to legume/cereal intercropping systems.
出处
《中国生态农业学报》
CAS
CSCD
北大核心
2016年第9期1169-1176,共8页
Chinese Journal of Eco-Agriculture
基金
国家自然科学基金项目(31360323)
国家科技支撑计划项目(2012BAD14B10)资助~~
关键词
玉米/豌豆间作
空间结构
间作作物间距
氮阻遏
根瘤
氮素利用效率
营养竞争比率
Maize/pea intercrop
Spatial structure
Spacing between intercropped crops
N inhibition
Root nodule
Nitrogen use efficiency
Ratio of nutrient competition