Controlling indeterminate lentil crop growth through nitrogen supply

小扁豆是一种不确定的豆类作物，这意味着它有一种生长习性，在生殖生长过程中营养生长继续进行。相比之下，确定的习性有一个营养阶段，然后是明显的生殖生长阶段，例如在草类中。在多雨的年份，当它有高氮(N)供应时，小扁豆在草原上的短生长季不能成熟，导致产量低而不稳定。由于尚未发现确定的小扁豆基因型，我们相信，通过作物供氮来控制营养生长和生殖生长之间的平衡的农艺方法可能会为这种延迟成熟提供解决方案。在草原上，这种不确定的习性要么依靠终端胁迫(干旱、霜冻、缺氮)，要么依靠化学干燥来停止生长。小扁豆可以通过生物固氮获得大部分氮，这是根瘤菌和植物之间的一种共生关系，发生在根瘤中。小扁豆还可以利用肥料N，或通过土壤矿化过程提供土壤N。种植者依赖于固氮，但土壤无机氮可能是有效的，这取决于以前的土壤历史、气候和矿化作用。在这项研究中，我们计划调查如何通过四种策略来管理小扁豆的不确定性。第一个是检验在免耕和常规耕作土壤中小扁豆成熟度是否可以通过土壤供氮来控制。第二个是测试低浓度的干燥剂在高N条件下是否会引发衰老和成熟。第三种策略是测试商业种植的九种小扁豆在生殖生长期间对N的吸收、N的固定或N在植物内的重新分配是否存在差异。最后，第四个策略是鉴定衰老较早的根瘤菌，这样固氮只会发生到生殖生长中期。综上所述，所有这些策略将使我们详细了解N是如何在小扁豆中分配的，以获得令人满意的作物成熟度。

Lentil is an indeterminate pulse crop, which means it has a growth habit where vegetative growth continues during reproductive growth. In contrast, the determinate habit has a vegetative phase followed by a distinct switch to reproductive growth, for example, in grasses. In wet years and when it has a high nitrogen (N) supply, lentil fails to mature in the short growing season on the Prairies, resulting in low unstable yields. Because a determinate lentil genotype has not yet been found, we believe an agronomic approach of controlh'ng the balance between vegetative and reproductive growth through crop N supply may provide a solution to this delayed maturity. On the Prairies, the indeterminate habit is managed by relying on either a terminal stress (drought, frost, lack of N) or chemical desiccation to cease growth. Lentil can derive most of its N through biological N fixation, a symbiotic relationship between rhizobia bacteria and the plant that takes place in nodules on the roots. Lentil can also use fertilizer N, or soil supplied N through the process of soil mineralization. Growers depend on N fixation, but soil inorganic N may be available depending on the previous soil history, climate and mineralization. In this research, we plan to investigate how lentil indeterminacy can be managed by four strategies. The first is to test if lentil maturity can be controlled by soil N supply in zero tillage and conventional tillage soils. The second is to test if a desiccant at low concentrations can trigger senescence and maturity under high N conditions. The third strategy is test if nine lentil genotypes that are commercially grown vary in N uptake, N fixation, or N redistribution within the plant during reproductive growth. Finally, the fourth strategy is to identify earlier senescing rhizobia strains so N fixation will only occur up to mid-reproductive growth. Together, all these strategies will give us a detailed understanding of how N is partitioned in lentil in order to have satisfactory crop maturity.