摘要
合理的土地利用模式可改善土壤碳、氮平衡。为了探究河西灌区连作蔬菜地轮作紫花苜蓿施氮对土壤碳氮特征和紫花苜蓿生产性能的影响,本研究以永昌县种植7年娃娃菜后,轮作5年紫花苜蓿的土地为对象,设5个施氮水平(0、51.75、103.5、155.25、207 kg·hm^(-2)),对土壤碳、氮含量、土壤酶、土壤微生物生物量碳、氮以及紫花苜蓿产量和氮积累量进行研究。结果表明:轮作紫花苜蓿后,土壤养分得到改善,土壤酶活性和微生物生物量碳、氮增加,其中有机碳含量比轮作紫花苜蓿前提高2.0%。适宜水平的施氮量可以有效提高土壤脲酶、蔗糖酶活性和土壤微生物生物量碳、氮,尤其对0~40 cm土壤的提高效果最明显,还可以显著提高紫花苜蓿产量和氮素积累量;当施氮量为103.5 kg·hm^(-2)时,紫花苜蓿土壤碳、氮含量提高最明显,苜蓿产量和氮素积累量也最高。综上,连作蔬菜地后茬轮作紫花苜蓿不仅可以改善土壤质量,还可以进行牧草生产。综合施氮对土壤碳、氮特征和紫花苜蓿生产性能的影响效果,施氮量为103.5 kg·hm^(-2)既能改善土壤质量,提高土壤肥力和土地生产力,又能保证紫花苜蓿的高产优质生产。
Appropriate land utilization model can facilitate soil carbon(C) and nitrogen(N) ba-lance. We investigated the effects of N application and alfalfa rotation on soil C and N characteristics and forage production performance of the field with alfalfa after growing vegetables in Hexi irrigated area. Five N application levels(0, 51.75, 103.5, 155.25 and 207 kg·hm^(-2)) were set up in an alfalfa field in Yongchang County, in which baby Chinese cabbage had been planted for seven years and then alfalfa for five years. We measured the contents of soil C and N, soil enzymes, soil microbial biomass C and N, alfalfa biomass and N accumulation. The results showed that soil nutrient contents were improved, soil enzyme activities and microbial biomass C and N were increased after alfalfa rotation. Soil organic C content was increased by 2.0% compared with that before alfalfa rotation. The activities of soil urease and sucrase and the contents of soil microbial biomass C and N were significantly increased at the appropriate level of N application, especially in 0-40 cm soil, while alfalfa biomass and nitrogen accumulation were significantly increased. When the N application rate was 103.5 kg·hm^(-2), the contents of soil C and N were increased most obviously, and the biomass and N accumulation of alfalfa were also improved to the highest level. In conclusion, rotation of alfalfa after continuous cropping of vegetables could not only improve soil quality, but also promote forage production. From the perspectives of soil C and N characteristics and production performance of alfalfa, the N application rate of 103.5 kg·hm^(-2)could not only improve soil quality, soil fertility, and land productivity, but also ensure the high forage production with high quality of alfalfa.
作者
吴勇
刘晓静
蔺芳
蒯佳琳
WU Yong;LIU Xiao-jing;LIN Fang;KUAI Jia-lin(College of Grassland Science,Gansu Agricultural Univer-sity/Key Laboratory of Pratacultural Eeosystem,Ministry of Education/Pratacultural Engineering La-boratory of Gansu Province/Sino-US Center for Grazingland Ecosystem Sustainability,Lanzhou730070,China;Vegetable Research Institute,Gansu Academy of Agricultural Sciences,Lanzhou730070,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2021年第11期4011-4020,共10页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(32171674)
甘肃省重点研发计划项目(20YF8NA130)资助。
关键词
蔬菜田
轮作
紫花苜蓿
施氮效应
土壤碳氮特征
饲草生产
vegetable field
rotation
alfalfa
nitrogen application effect
characteristics of soil carbon and nitrogen
forage production
