玉米和大豆在单作和混作系统中的氮行为研究

N Behaviour of Soybean and Maize Plants in Monoculture and Mixture

本文于１９９２年～１９９３年用１５Ｎ示踪稀释技术分别通过盆栽和大田小区试验，研究了大豆和玉米植株在单作和混作系统中的氮行为．混作时玉米植株来自土壤和肥料氮分别平均比单作时降低了９．１３％～２４．５８％和７．１５％～２２．５２％，减低了玉米植株对土壤和肥料氮的剧烈竞争．混作时大豆植株固定的氮除供本身生长发育用外，还能转移给与之混作的玉米植株．输出率达到１８．４４％～３５．３２％，使玉米植株从与之混作的大豆植株的根际获得本身生长所需氮的８．７５％～２４．０５％．这种负反馈机制又使混作系统中大豆植株的固氮百分率比单作时提高了２９．１０％～３２．６９％．大豆与玉米以２：１株数比种植时，在各试验组合中表现出氮营养优势．

A N behaviour research of maize and soybean plants in monoculture and 9. 13%─24. 58% and 7. 15%─22. 52% respectively compared with that in the monoculture.The Ndfa of soybean plants in mixture could be transfered to maize plants and % Ndft was 18. 44%─35. 32%, 8. 75%─24. 05% of N of maize plants in mixture were from the Ndfa of soybean plants. It is one of the reasons that the%Ndfa of soybean plants had an increase by 29. 10%─32. 69% in the mixture of maize and soybean plants.