School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, S7N 5A6.
Mycorrhiza. 2010 Nov;20(8):541-9. doi: 10.1007/s00572-010-0305-7. Epub 2010 Feb 24.
Phosphorus (P) can be low in soil under low input organic management; however, beneficial crop plant associations with arbuscular mycorrhizal fungi (AMF) are known to promote crop nutrition and increase phosphorus uptake. Thus, management strategies that promote AMF associations are particularly desirable for low-input cropping systems. The objectives of this study were to determine the impact of seeding rate on AMF colonization and the impact of AMF colonization on P concentration and uptake by organically grown field pea and lentil. Field experiments examined the impact of three seeding rates of field pea and lentil on P uptake and crop yield. Phosphorus accumulation was examined further in a controlled growth chamber experiment, in which field pea was sown at rates corresponding to those used in the field and harvested at 10-day intervals until 50 days after emergence. In the field, the level of AMF colonization of roots remained at 80% for field pea, while colonization of lentil increased with increasing seeding rates from 77% to 88%. The level of AMF colonization of field pea achieved in the growth chamber after 50 days was 80% for the two highest seeding rates and 60% for the low seeding rate. The rate at which AMF colonization occurred did not vary between treatments. Ultimately, AMF colonization level did not affect P accumulation. In contrast to several previous studies, both field and growth chamber experiments revealed that AMF colonization was not reduced at higher seeding rates. These results suggest that organic farmers may increase seeding rates without adversely affecting P nutrition.
在低投入有机管理下，土壤中的磷（P）可能很低；然而，与丛枝菌根真菌（AMF）有益的作物植物组合已知可以促进作物营养并增加磷的吸收。因此，促进 AMF 共生的管理策略对于低投入的种植系统尤为可取。本研究的目的是确定播种率对 AMF 定殖的影响，以及 AMF 定殖对有机种植的豌豆和小扁豆中磷浓度和吸收的影响。田间试验研究了三种豌豆和小扁豆播种率对磷吸收和作物产量的影响。在受控生长室实验中进一步研究了磷的积累情况，在该实验中，以与田间使用的播种率相对应的速度播种豌豆，并在出苗后 50 天内每隔 10 天收获一次。在田间，豌豆根的 AMF 定殖水平保持在 80%，而随着播种率的增加，小扁豆的定殖水平从 77%增加到 88%。在生长室中，经过 50 天后，最高两种播种率的豌豆 AMF 定殖水平为 80%，低播种率为 60%。AMF 定殖率在处理之间没有差异。最终，AMF 定殖水平并没有影响磷的积累。与之前的几项研究相反，田间和生长室实验都表明，在较高的播种率下，AMF 定殖并没有减少。这些结果表明，有机农民可以增加播种率而不会对磷营养产生不利影响。
