摘要
通过测定并分析不同杂草盖度紫花苜蓿田苜蓿叶、茎以及0~30cm土壤中N、P含量及其氮磷比,研究了不同杂草盖度对苜蓿、杂草和土壤N、P生态化学计量特征的影响。结果表明:紫花苜蓿人工草地自第二茬时出现较多杂草,对照组的土壤全N含量较高;杂草中度侵害等级的土壤全P含量较高;对照组和杂草轻度侵害等级的土壤氮磷比较高。苜蓿叶和茎的N、P含量及氮磷比均受杂草盖度的影响,且第二茬和第三茬的苜蓿叶氮磷比小于14,说明苜蓿的生长受氮限制,可在其刈割后追施氮肥。在同一杂草侵害等级下,第三茬苜蓿叶和茎的N、P含量均高于第一茬和第二茬。在不同杂草侵害等级和不同茬次下,相同杂草的N、P含量及氮磷比也不相同;苜蓿叶、茎和土壤中N、P含量以及氮磷比均能影响相应杂草的N、P生态化学计量特征,并发现特定的变化趋势。
Through the measurement and analysis of N, P and N.P of the alfalfa leaf, stem and 0-30 cm of soil, the study inquired a relation of N, P contents and N.P between afalfa, weed and soil in different weed coverage of alfalfa grassland. The results showed that, there were more weeds in alfalfa field since the second cut. The soil N content of contrast group was higher than other in alfalfa grassland; The soil P content was higher than other in alfalfa field with medium level of weed invasion; The soil N：P was higher in contrast group and slight level of weed invasion; The N, P contents and N：P of alfalfa leaf and stem were influenced by weed coverage. The N：P of alfalfa leaf were less than 14 at the second or third cut so that the growth of alfalfa was limited by N element. Then, N fertilizer was applied since alfalfa cutting. Under same level of weed invasion, the N and P contents of third cut of alfalfa leaf and stem were higher than the first and second cuts of them. The same weed had different N, P contents and N：P in different level of weed invasion and different cut; The N and P stoichiometry characteristic of weed was affected by N, P contents and N.P of alfalfa and soil. Then, no specific trend was found.
出处
《青岛农业大学学报（自然科学版）》
2017年第3期183-190,共8页
Journal of Qingdao Agricultural University(Natural Science)
基金
国家牧草产业技术体系(CAWS-35)
山东省现代农业产业技术体系牧草创新团队(SDAIT-23-08)
青岛农业大学高层次人才启动基金(6631116024)
青岛农业大学大学生科技创新项目"农区冬闲牧草混播的系统生产力及杂草多样性的研究"
公益性行业科研专项(201403048)
