小麦根系生理活性时空分布与土壤有效养分的关系

为了解小麦根系生理活性时空分布与土壤有效养分含量的关系，在2019-2021年两个小麦生长季，于小麦的不同生育时期采用长方体铁盒(0.2 m×0.05 m×0.2 m)在麦行上、行距1/4处、行距1/2处分别取0～0.2 m和0.2～0.4 m土层的样品，测定不同位点小麦根系生物量、根系活跃吸收面积、根总吸收面积、根系活力，以及土壤碱解氮、有效磷和速效钾含量。结果表明，0～0.2 m和0.2～0.4 m土层中小麦根重密度、根总吸收面积和根系活跃吸收面积随生育时期的推进均呈先升后降的变化趋势；根系活力、根群生理势均呈“低-高-低-高-低”的变化趋势。0～0.2 m土层的根重密度、根总吸收面积、根系活跃吸收面积、根群生理势均显著高于0.2～0.4 m土层。在灌浆之前，0～0.2 m土层根系活力高于0.2～0.4 m土层；在灌浆到成熟期间，下层根系的根系活力显著增大。在整个生育期内，0～0.2 m土层中根重密度、根总吸收面积、根系活跃吸收面积和根群生理势的水平分布表现为行上>行距1/4处>行距1/2处；开花期之前，根系活力在行距1/4处最大，开花到成熟期间根系活力水平分布表现为行...

Relationships between Spatiotemporal Distribution of Root Physiological Function and Dynamics of Soil Available Nutrient Content in Wheat(Triticum aestivum L.)

In order to clarify the temporal and spatial distribution of wheat root physsiological activity and relationship with available nutrient content, during the two-year wheat growing seasons from 2019 to 2021,the samples at different developmental stages were collected using the cubic iron boxes (0.2 m×0.05 m×0.2 m) in 0-0.2 m and 0.2-0.4 m soil layers at the wheat row,1/4 row space,and 1/2 row space,to determine the root biomass,active root absorption area,total root absorption area,root vigor,dry root weight density and root physiological potential.Contents of available nitrogen,available phosphorus,and available potassium in different soil layers and horizontal sites were analyzed.The results showed that,in 0-0.2 m and 0.2-0.4 m soil layers,dry root weight density,total root absorption area and active root absorption area were first increased and then decreased with the development of growing period.The curves of root vigor and root physiological potential were shaped as an M with the development of growing period.For the vertical distribution of wheat root,dry root weight density,total root absorption area,active root absorption area and root physiological potential in 0-0.2 m soil layer were significantly higher than those in 0.2-0.4 m soil layer(P<0.05).Root vigor in 0-0.2 m soil layer was higher than that in 0.2-0.4 m soil layer at each growth stage before grain-filling,and root vigor in 0.2-0.4 m layer was increased from grain-filling stage to mature stage.In the whole growing period,the horizontal distribution of dry root weight density,total root absorption area,active root absorption area and root physiological potential in 0-0.2 m soil layer ranked as in the wheat row > in 1/4 row space > in 1/2 row space.Root vigor was the highest in 1/4 row space pre-anthesis.From anthesis to mature stage,the horizontal distribution of root vigor ranked as in 1/2 row space > in 1/4 row space > in the wheat row.In 0-0.2 m and 0.2-0.4 m soil layers,dry root weight density,total root absorption area and active root absorption area were significantly negatively correlated with contents of soil available nitrogen,soil available phosphorus and soil available potassium during the whole growing period(P<0.01).In 0-0.2 m soil layer,root vigor was significantly positively correlated with contents of soil available nitrogen,soil available phosphorus and soil available potassium(P<0.01).In 0.2-0.4 m soil layer,root vigor was significantly positively correlated with contents of soil available phosphorus and soil available potassium (P<0.01).In 0-0.2 m and 0.2-0.4 m soil layers,root physiological potential was significantly positively correlated with content of soil available potassium(P<0.01).The root active absorption area and the ability to absorb soil nutrients were less in deeper soil layer.In the late wheat growth stage,root vigor increased in the deep soil layer.In 0-0.2 m soil layer,the root active absorption area and the ability to absorb soil nutrients showed stronger in the samples closer to the wheat row.In the middle and late wheat growth stage,the root vigor showed higher in the samples closer to the wheat row.