摘要:玉米/大豆间作具有一定的养分利用优势，但是不同供氮水平对玉米/大豆间作体系干物质累积和氮素吸收的调控作用不同。本试验采用田间裂区设计，运用Logistic模型分析，模拟了4个氮水平下玉米/大豆间作作物干物质积累和氮素吸收的动态变化。结果表明，玉米、大豆干物质累积和氮素吸收动态符合Logistic模型，相关系数R2均在0.9以上。在N0（不施氮肥）、N1（180 kg·hm-2）、N2（240 kg·hm-2）和N3（300 kg·hm-2）供氮水平时，间作玉米最大生长速率（Imax-B）分别比单作提高34.2%、46.7%、25.9%和25.1%，而相应的供氮水平下，大豆的Imax-B分别降低27.7%、30.3%、16.5%和23.7%，但整个间作系统的Imax-B平均增加32.1%；玉米和大豆干物质的其他模拟参数与Imax-B规律一致。氮素吸收动态与干物质积累表现出同步的变化特点，在N1水平下，单位面积间作玉米的氮素最大吸收量（K-N）、最大吸收速率（Imax-N）和瞬时吸收速率（r-N）比相应单作分别提高18.4%、48.9%和25.8%，而间作大豆的K-N、Imax-N和r-N值比单作处理分别降低15.9%、29.9%和16.69%，整个间作系统氮素分别提高0.4%、13.7%和7.8%；施氮水平对大豆r-N无显著性影响。间作显著地提高了氮素当量比（LERN>1），其中N0水平下LERN值最高，随着施氮量的增加，LERN有下降趋势。在本试验条件下，N2供氮水平下玉米/大豆间作体系干物质积累量和氮素吸收量最高，间作优势最明显。
关键词:玉米/大豆间作/
干物质累积/
氮素吸收量/
间作优势/
Logistic模型
Abstract:Maize/soybean intercropping has yield advantages to an extent. However, different nitrogen supply levels have different effects on dry matter accumulation and nitrogen uptake in the maize/soybean intercropping system. A field experiment with a split design and logistic model were used to simulate dynamic changes in dry matter accumulation and nitrogen uptake in a maize/soybean intercropping system supplied with four nitrogen levels. Simulation results showed that dry matter accumulation and nitrogen uptake dynamics in maize and soybean were consistent with the logistic model, with correlation coefficients (R2) higher than 0.9 at the four nitrogen levels. The maximum growth rate (Imax-B) of intercropped maize compared with monoculture increased by 34.2%, 46.7%, 25.9% and 25.1% when the nitrogen supply levels were N0 (without N supply), N1 (180 kg·hm-2), N2 (240 kg·hm-2), and N3 (300 kg·hm-2), respectively. The Imax-B of the soybean decreased by 27.7%, 30.3%, 16.5%, and 23.7%, respectively. However, the average Imax-B in the intercropping system was increased by32.1%. The other dry matter simulation parameters of maize and soybean were consistent with the Imax-B. Additionally, nitrogen uptake dynamics showed synchronous changes with dry matter accumulation. Under N1 treatment, the maximum nitrogen uptake (K-N), maximum uptake rate (Imax-N), and instantaneous uptake rate (r-N) of intercropped maize was 18.4%, 48.9%, and 25.8% higher than that of the monoculture, while the K-N, Imax-N, and r-N of the intercropped soybean was 15.9%, 29.9%, and 16.69% lower than that of the monoculture, respectively. The simulation parameters of K-N, Imax-N, and r-N in the intercropping system were 0.4%, 13.7%, and 7.8% higher than those of monoculture, respectively. Nitrogen supply had no significant effect on r-N of soybean. A significant advantage of nitrogen in the intercropping system was observed with nitrogen land equivalent ration (LERN)>1, and the LERN value under N0 treatment was the highest. With the increase in nitrogen application, the LERN exhibited a downward trend. In the present experiment, the highest dry matter accumulation and nitrogen uptake were observed under N2 treatment, which had obvious advantages for intercropping.
Key words:Maize/soybean intercropping/
Dry matter accumulation/
Nitrogen uptake/
Intercropping advantage/
Logistic model
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