摘要
在低丘红壤花生—南酸枣间作系统中利用1 5N同位素示踪方法研究结果表明 ,5龄和 9龄南酸枣分别竞争利用了施用于花生的氮肥的 9 66%和 3 0 15 %。与单作花生系统相比 ,5龄和 9龄南酸枣间作系统中花生对表施氮肥的利用率分别下降 3 7 8%和 5 9 1%。间作 5龄南酸枣对模拟淋溶至亚表层土壤氮素的利用率非常低下 ,与花生单作相比 ,5龄南酸枣间作系统表施氮素土壤残留没有显著差异 ,其安全网作用不明显。随着树龄增加 ,南酸枣根系充当安全网作用的潜力被证实。 9龄南酸枣对模拟淋溶至3 5cm和 5 5cm深度土壤氮素的利用率分别为 3 3 79%和 14 74% ,与花生单作相比 ,其表施氮素在 0～ 60cm土层残留降低 2 4 1%。
N-labell fertilizer was used to study on N competition between tree and peanuts, and to test the potential of tree roots acting as safety-net on Choerospondias axillaris cropped with peanut ( Arachis hypogaea ) in subtr opical China. Five-year-old and nine-year-old Choerospondias axillaris r ecovered 9 66% and 30 15% of the N applied at topsoil of peanut area, respectively. Compared with sole peanut system, N recovery by peanut was decreased by 37 8% in 5-year-old and 59 1% in 9-year-old Choerospondias axillaris alley cropping system, respectively. T he rol e of 5-year-old Choerospondias axillaris acting as a safety-net was not o bvious, since it recovered little N from subsoil and did not decrease N residual in the soils. With increasing tree age, 9-year-old Choerospondias axillaris show ed its potential to act as a safety-net, since it recovered 33 79% N from 35cm soil la yer and 14 74 % N from 55 cm soil layer, respectively, and N residual in 0～60 c m soil layer was decreased by 24 1%, compared with that in sole peanut system.
出处
《土壤学报》
CAS
CSCD
北大核心
2003年第4期588-592,共5页
Acta Pedologica Sinica
基金
中国科学院知识创新项目 (KZCX2 -4 0 7)
国家重点基础研究发展规划项目(G19990 1180 1)
IAEA合作项目部分成果
