摘要
[目的]禾豆间作可兼顾生产和生态效益,提高氮素利用效率并减少氮肥污染。目前对不同水分条件下禾豆间作体系氮素利用吸收及转移分配过程尚不清晰。[方法]通过设置2时段总水量相同但间隔3,5天的不同频次水处理,结合根系分隔(不分隔、尼龙网分隔、塑料板分隔)和氮同位素标记方法,研究间作禾豆牧草的地上生物量、氮素的吸收利用、固氮率和氮转移率。[结果]间作披碱草的地上生物量、氮含量和氮素累积量相较单作披碱草显著提升,而苜蓿间作相比单作均降低。在总水量持平的情况下,高频水分处理使牧草的地上生物量比中低频水分处理分别提高6.28%,17.32%,苜蓿的固氮率也在高频水处理下比中低频水处理分别提高39.82%,44.81%,但部分中低频水分处理下氮含量和氮素累积量显著高于高频水分处理(p<0.05),且促进氮素的转移。根系分隔使禾豆相互作用减弱,表现为根系分隔增加间作苜蓿的地上生物量、各部位氮含量及地上部氮素累积量,减小间作披碱草的对应指标。间作苜蓿的固氮和氮转移率表现为不分隔>尼龙网分隔>塑料板分隔。[结论]适度的水分调控可以提高禾豆间作的优势,且根系互作是促进豆科牧草生物固氮和氮转移的关键。
[Objective]Gramineae-legume intercropping can give consideration to production and ecological benefits,improve nitrogen use efficiency and reduce nitrogen pollution.At present,the process of nitrogen utilization,absorption and transfer distribution in gramineae-legume intercropping systems under different water conditions is not clear.[Methods]The above ground biomass,nitrogen absorption and utilization,nitrogen fixation rate,and nitrogen transfer rate of gramineae-legume intercropping were studied by using water treatment with the same total water amount in 2 periods but with an interval of 3 or 5 days,combined with root separation(non-separation,nylon mesh separation and plastic plate separation)and nitrogen isotope labeling methods.[Results]The aboveground biomass,nitrogen content and nitrogen accumulation of E.dahuricus intercropped with alfalfa were significantly increased compared with monoculture E.dahuricus,while,for alfalfa,the intercropping with E.dahuricus resulted in a decrease compared to monoculture alfalfa.Under the condition of the same total water amount,the above-ground biomass of the herbage increased by 6.28%and 17.32%,respectively,by high-frequency water treatment compared with medium and low frequency water treatments,and the nitrogen fixation rate of alfalfa was increased by 39.82%and 44.81%,respectively,under high-frequency water treatment compared with medium and low frequency water treatments.However,the nitrogen concentration and nitrogen accumulation under some middle and low frequency water treatments were significantly higher than those under high frequency water treatment(p<0.05),and promoted nitrogen transfer.Root separation weakened the interaction between grass and bean,and showed that as root separation increased the aboveground biomass,nitrogen concent and aboveground nitrogen accumulation of intercropping alfalfa,and decreased the corresponding indexes of intercropping E.dahuricus.The nitrogen fixation and nitrogen transfer rate of alfalfa intercropping were in the order of no
作者
王一帆
刘华清
赵西宁
高晓东
WANG Yifan;LIU Huaqing;ZHAO Xining;GAO Xiaodong(College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling,Shaanxi 712100,China;Institute of Soil and Water Conservation,CAS&MWR,Yangling,Shannxi 712100,China;College of Soil and Water Conservation Science and Engineering,Northwest A&F University,Yangling,Shannxi 712100,China)
出处
《水土保持学报》
CSCD
北大核心
2024年第4期279-287,共9页
Journal of Soil and Water Conservation
基金
区域创新发展联合基金重点项目(U22A20613)
国家重点研发计划项目(2021YFD1900700)
国家自然科学基金项目(42125705)。
关键词
禾豆间作
根系分隔
水分处理
氮素利用
氮转移效率
gramineae-legume intercropping
root separation
water treatment
nitrogen utilization
nitrogen transfer efficiency
