四川玉米-大豆带状套作复合群体产量变异及其影响因素分析

Variation of combination yield of maize and soybean under maize- soybean inter- cropping system in Sichuan Province

选取四川省射洪、仁寿、广安3个典型丘陵农业生态区,调查了各区域2004-2012年的玉米-大豆套作复合群体的产量及其构成因素的变化,探讨了玉豆套作复合群体最大理论产量及其同各构成因素间的关系。结果表明,就玉米-大豆套作而言,四川存在大面积的中低产地块,其比例高达80.2%。根据实际产量计算获得的射洪、仁寿、广安玉豆复合群体最大理论产量显著高于各自的实际最高产量,说明提升潜力巨大。通径分析表明,在不同区域内,复合群体主要的产量构成因素对群体产量的贡献率有差异,其中大豆和玉米的有效株数最为重要。此外,土壤有机质、全氮、速效氮、速效钾含量的差异,是导致复合群体产量差异的主要肥力因素。因此,玉米大豆套作高产栽培技术应以增加播种密度为核心,提高玉米有效穗数和大豆有效株数,辅以有效的土壤改良措施,这是玉豆复合群体高产、稳产的重要保证。

Shehong,Renshou and Guangan,the 3 typical hill counties in Sichuan Province,were selected in this study. The yield of combination of maize- soybean from 2004 to 2012 in these sites was investigated,including compositions of the total yield in the maize- soybean inter- cropping system,which was dominant in Southwest China. The largest theoretical yield of the system was evaluated and the relationship between yield and compositions were discussed. Results demonstrated that,the low yield of combination of maize- soybean was accounted for up to80. 2% of the total areas in Sichuan Province. In addition,the largest theoretical yield in this system was significantly higher than the actual yield,which sugested that there were great potential for improving yield in maize-soybean intercropping system in Southwest China. Furthermore,the path analysis indicated that different yield components had their distinct contributions for the total yield,and among them the effective stalks of maize and soybean were the most important determinants. On the other hand,the soil fertility components including organic matter,total nitrogen,available nitrogen,available potassium could also make great contributions to the total yield of maize-soybean intercropping system. Therefore,the proposals for the high- yield cultivation for maize- soybean intercropping system should be employed strictly; the effective stalks of maize and soybean should be increased; and effectively soil improvement and rationalized manuring system were employed. In a word,the high yield of the maize and soybean could be achieved through employing these effective strategies described above.