摘要
[目的]针对青藏高原地区麦类作物长期连作和不合理施肥导致土壤有机碳和作物产量降低等问题,探究不同绿肥种植模式及施氮制度对土壤有机碳含量和作物产量的影响,以期为试区土壤固碳和作物产能提升提供理论依据和技术支撑.[方法]基于2018年在青海大学农林科学院试验站布设的长期定位试验展开,试验采用双因素裂区设计,主区设2种施氮制度:总施氮量为180 kg/hm2,春小麦和绿肥分施100%和0%(N1)、80%和20%(N2),副区设3种麦后复种绿肥模式:春小麦-箭筈豌豆(W-V)、春小麦-油菜(W-R)和春小麦-箭筈豌豆×油菜(W-VR);共6个处理.2020和2021春小麦收获后采集耕作层(0～30 cm)土样,测定了土壤中的有机碳及其组分含量.[结果]0～30 cm土层施氮制度N2与N1差异显著(P<0.05),N2较N1处理土壤有机碳、可溶性有机碳、热水提取有机碳和易氧化有机碳含量分别提高4.7%、2.9%、7.9%和4.5%,小麦籽粒产量提高12.1%;麦后复种不同绿肥0～30 cm土层有机碳含量差异显著(P<0.05),W-VR较W-V和W-R处理土壤有机碳含量提高7.6%和15.1%,土壤可溶性有机碳含量提高5.6%和10.80%,土壤热水提取有机碳含量提高4.9%和15.7%,土壤易氧化有机碳含量提高7.5%和13.6%,籽粒产量分别提高4.9%和11.1%;麦后复种绿肥模式与施氮制度交互作用对土壤有机碳含量影响显著,W-VRN2较传统种植模式W-VN1土壤有机碳、热水提取有机碳和易氧化有机碳分别提高12.6%、13.0%和12.5%,小麦籽粒产量提高17.7%.[结论]麦后混播箭筈豌豆和油菜结合绿肥施氮20%可有效增加土壤有机碳含量,提高小麦籽粒产量,是青藏高原地区比较合理的绿肥种植模式和施氮制度.
Abstract
[Objective]In view of the problems of long-term continuous cropping and irrational fertiliza-tion of wheat crops in the Qinghai-Tibet Plateau,which lead to the reduction of soil organic carbon and crop yield,the effects of different green manure planting patterns and nitrogen fertilization systems on soil or-ganic carbon content and crop yield were investigated to provide a basis for soil sequestration in the experi-mental area.[Method]This study is based on the long-term positioning experiment set up at the experimen-tal station of the Academy of Agriculture and Forestry,Qinghai University in 2018.The experiment ad-opted a two-factor split-plot design,and two nitrogen fertilization systems were set up in the main plot.The total nitrogen fertilization rate was 180 kg/hm2,and spring wheat and green manure were divided into two systems.100%and 0%(N1),80%and 20%(N2),and three green manure patterns for multiple cropping af-ter wheat were established in the subplot:spring wheat-Vicia sativa(W-V),spring wheat-rape(W-R)and spring wheat-Vicia sativa×rape(W-VR);6 treatments in total.Soil samples in the ploughing layer(0～10 cm and 10～30 cm)were collected after the spring wheat harvest in 2020 and 2021,and soil organic car-bon and its components were determined.[Result]There was a significant difference between N2 and N1 in the 0～30 cm soil nitrogen application system(P<0.05),and the contents of soil organic carbon,soluble or-ganic carbon,hot water extraction organic carbon and easily oxidizable organic carbon were increased by 4.7%in N2 compared with N1,2.9%,7.9%and 4.5%,the yield of wheat grain increased by 12.1%.The content of organic carbon in the 0～30 cm soil layer of different green manures after wheat was significantly different(P<0.05),and the soil organic carbon content of W-VR was higher than that of W-V and W-R.content increased by 7.6%and 15.1%,soil soluble organic carbon content increased by 5.6%and 10.80%,soil hot water extraction organic carbon content increased by 4.9%and 15.7%,soil easily oxidiz-able organic carbon content increased by 7.5%and 13.6%,and grain yield increased by 4.9%and 11.1%.The interaction between wheat post-wheat green manure mode and nitrogen application system has a sig-nificant effect on soil organic carbon content,and W-VRN2 has a higher level of soil organic carbon,hot wa-ter extraction organic carbon and easily oxidized organic carbon than traditional planting mode W-VN1 re-spectively increased by 12.6%,13.0%and 12.5%,wheat grain yield increased by 17.7%.[Conclusion]Mixed sowing of Vicia sativa and rapeseed after wheat combined with 20%nitrogen application of green manure can effectively increase soil organic carbon content and increase wheat grain yield,which is a reason-able green manure planting pattern and nitrogen application system in the Qinghai-Tibet Plateau.
维普
万方数据