Nutrient relations of winter wheat: 2. Movement of nutrients to the root and their uptake
Nutrient relations of winter wheat: 2. Movement of nutrients to the root and their uptake
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冬小麦的养分关系：2.养分向根部的移动及其吸收
DOI：
10.1017/s0021859600038193
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发表时间：
1979
影响因子：
0.6
通讯作者：
M. McGowan
中科院分区：
文献类型：
--
作者：
Peter J. Gregory;D. Crawford;M. McGowan
本工作的目的是确定质量流和扩散在向小麦植株提供养分方面的相对重要性，并计算根系（流入）的养分吸收率。在大田条件下，对冬小麦植株Na、K、Ca、Mg、P、S、N含量、根长、植株吸水量和土壤溶液浓度进行了定期测定。4月中旬至6月中旬，物质流对植物吸收养分的表观贡献大于测得的植物吸收钠、钙、镁和硫（分别为14、9、2和4倍）;然而，测得的植物吸收氮和钾的50%和磷的5%以这种方式提供。有一些7天的时间，当质量流能够提供测量的氮和钾的吸收，它是可能的，这些营养物质的质量流和扩散的重要性可能会改变生长过程中。计算从播种到6月中旬的平均流入量（以mol/cm根/秒为单位的吸收量）.流入量下降，所有的营养物质从高初始值到低价值在冬季再次上升，在4月中旬和5月下降之前，在6月。在4月中旬流入的增加是伴随着增加的芽生长，但控制植物的营养需求和吸收在该领域的确切因素仍然不明确。
SUMMARY The purpose of this work was to determine the relative importance of mass flow and diffusion in supplying nutrients to wheat plants and to calculate nutrient uptake rates by roots (inflow). Winter wheat was grown in the field and measurements of plant Na, K, Ca, Mg, P, S and N contents, root length, plant water uptake and soil solution concentration made at regular intervals during growth. The apparent contribution of mass flow to plant uptake of nutrients between mid- April and mid-June was greater than the measured plant uptake for sodium, calcium, magnesium and sulphur (14, 9, 2 and 4 times respectively); however, only 50 % of the measured plant uptake of nitrogen and potassium and 5% of the phosphorus was supplied in this way. There were some 7 day periods when mass flow was able to supply the measured uptake of nitrogen and potassium, and it is possible that for these nutrients the importance of mass flow and diffusion may change during growth. Mean inflows (uptake in mol/cm root/sec) were calculated from sowing until mid- June. Inflow decreased for all nutrients from high initial values to low values during the winter and rose again in mid-April and May before falling in June. The increase in inflow in mid-April was concomitant with increased shoot growth but the precise factors controlling plant demand for nutrients and uptake in the field are still ill-defined.