摘要
【目的】探寻我国半干旱黄土高原区紫花苜蓿可持续生产的适宜有机覆盖垄沟集雨种植模式。【方法】采用随机区组设计布置大田试验,以平作(FP)为对照,研究秸秆炭覆盖垄沟集雨连续种植第5年不同秸秆炭覆盖量(0、30和60 t/hm^(2))和不同垄沟比(垄宽∶沟宽分别为30∶60、45∶60和60∶60(cm∶cm))对种植沟和集雨垄表层土壤结构和紫花苜蓿产量的影响。【结果】秸秆炭覆盖垄沟集雨种植显著降低沟和垄中表层土壤容重,显著提高同土层土壤孔隙度和改善土壤团聚体稳定性。随垄沟比增加,秸秆炭覆盖垄沟集雨种植对土壤结构影响不显著;随秸秆炭覆盖量增加,土壤容重和广义土壤结构系数(TSPI)呈减小趋势,土壤孔隙度呈增加趋势,>0.25 mm水稳性团聚体含量(WR0.25)和紫花苜蓿产量呈先增加后降低趋势。与FP相比,秸秆炭覆盖垄沟集雨种植紫花苜蓿全生育期实际干草产量提高3.6%~24.0%。与0和60 t/hm^(2)秸秆炭覆盖量相比,30 t/hm^(2)秸秆炭覆盖垄沟集雨种植具有较低土壤容重、较高土壤孔隙度和较好土壤团聚体稳定性,其土壤三相结构分布接近理想状态,促使紫花苜蓿产量提升。【结论】当秸秆炭覆盖量为30 t/hm^(2)和垄沟比为30∶60时,秸秆炭覆盖垄沟集雨种植紫花苜蓿产量提升效果最佳。未来生物炭应用长期时间尺度内土壤结构变化规律与紫花苜蓿根系构型间关系需进一步研究。
【Objective】To ensure the stability and sustainability of alfalfa productivity in the semi⁃arid Loess Pla⁃teau of China.【Method】A field experiment was conducted in randomized complete block design to determine the ef⁃fects of different maize straw biochar application rates(0,30,and 60 t/hm^(2))and ridge to furrow ratios(30∶60,45∶60 and 60∶60(cm∶cm))on soil structure and alfalfa forage yield during the fifth year of continuous planting of alfalfa,us⁃ing flat planting(FP)as a control.【Result】RFRH with maize straw biochar application significantly reduced soil bulk density,increased total porosity,and improved the soil aggregate water stability.As maize straw biochar applica⁃tion rates increased,soil bulk densityand three soil phase index(TSPI)decreased;total porosity increased;and WR0.25and alfalfa forage yield first increased and then decreased.Compared to FP,annual forage yields increased by 3.6%~24.0%inridge⁃furrowrainwaterharvesting with maize straw biochar application.Ridges compacted with maize straw biochar at an applicationrate of 30 t/hm^(2) had lower soil bulk density,higher total porosity,and improved soil wa⁃ter stability of aggregates.The soil three⁃phase distribution was closed to ideal state,which resulted in higher alfalfa forage yield compared with ridges compacted with maize straw biochar at an application rate of 0,and 60 t/hm^(2).【Conclusion】Maize straw biochar at an application rate of 30 t/hm^(2) and a30∶60(cm∶cm)ridge to furrow ratiowas⁃was found be suitable for increase fodder yield in semi⁃arid regions of China.Future researchshould be conducted in the form of long⁃term field study to determine relationship between biochar⁃inducing soil structure variety and root ar⁃chitecture of alfalfa.
作者
周旭姣
张晓娟
吕陇
徐彦花
柳小妮
王琦
ZHOU Xu-jiao;ZHANG Xiao-juan;LYU Long;XU Yan-hua;LIU Xiao-ni;WANG Qi(College of Grassland Science,Gansu Agricultural University,Key Laboratory for Grassland Ecosystem,Ministry of Education,Grassland Engineering Laboratory of Gansu Province,Sino-U.S.Centers for Grazing Land Ecosystem Sustainability,Lanzhou 730070,China)
出处
《草原与草坪》
CAS
CSCD
2023年第6期81-93,共13页
Grassland and Turf
基金
国家自然科学基金项目(42061050,41661059)。
关键词
紫花苜蓿
垄沟集雨
水稳性团聚体
容重
孔隙度
三相比
alfalfa
ridge⁃furrow rainwater harvesting
soil water stable aggregates
bulk density
total porosity
three⁃phase ratio
