甘肃农业大学农学院柴强教授团队在玉米/豌豆间作田中设置了三个玉米种植密度处理和两个氮处理，研究谷物的种植密度对间作系统中氮供应和作物的氮需求的影响。结果发表于Scientific Reports（IF=4.011）。
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Abstract
Cereal density may influence the balance between nitrogen (N) supply and crop N demand in cereal/legume intercrop systems. The effect of maize (Zea maysL.) plant density on N utilization and N fertilizer supply in maize/pea (Pisum sativumL.) strip intercropping was evaluated in a field study with sole maize, sole pea, and intercropped maize/pea with three maize densities (D1, 45,000 plants ha−1; D2, 52,500 plants ha−1; D3, 60,000 plants ha−1) and two N treatments (N0, 0 kg N ha−1; N1, 450 kg N ha−1for maize and 225 kg N ha−1for pea). Soil mineral N in intercropped strips decreased with increased maize density. Increased maize density decreased N accumulation for intercropped pea but increased it for maize and the sum of both intercrops. The land equivalent ratio for grain yield (LER grain) showed a 24–30% advantage for intercrops than corresponding sole crops, and was greater with D3 than D1 and D2. Maize/pea intercropping had 4–113% greater nitrogen use efficiency (NUE) than sole maize, which was enhanced with increased maize density. Increasing maize density improved the synchrony of N supply and crop demand in maize/pea strip intercropping.
谷物/豆类间作系统中，谷物的种植密度可能影响氮（N）供应和作物的氮需求之间的平衡。在玉米/豌豆间作田中设置了三个玉米种植密度处理（D1：45000株·ha-1；D2：52500株·ha -1；D3：60000株·ha-1）和两个氮处理（N0：0 kg N·ha-1；N1：玉米施肥450 kg N·ha-1，豌豆施肥225 kg N·ha-1）。间作带的土壤矿质氮含量随玉米种植密度的增加而降低。玉米种植密度的增加降低了间作豌豆的氮素积累，但增加了玉米的氮素积累和两种间作作物总的氮素积累。间作作物粮食产量的土地当量比（LER粮食）比相应单作作物高出24%-30%，D3高于D1和D2。玉米/豌豆间作的氮素利用效率（NUE）比单作高出4%-113%，且随着玉米种植密度的增加而提高。玉米种植密度的增加提高了玉米/豌豆间作带的氮素供需的同步性。
