Inoculant and fertilizer effects on lentil in the US northern Great Plains

Abstract

Lentil (Lens culinaris Medikus) is an important crop, averaging more than 250,000 ha in Montana and North Dakota during 2016–2021. However, relatively little is known about inoculant and fertility response in lentil in the U.S. northern Great Plains. The objective of this study was to evaluate the effect of rhizobial inoculant formulations (seed‐coat and soil‐applied) and nutrient additions (K, S, and micronutrients), on lentil yield and seed protein concentration. This study was conducted at seven university research centers in Montana and North Dakota from 2019–2021, resulting in 20 location‐years of data. In 6 of 20 experiments, inoculant application increased seed yield by an average of 36% (323 kg ha−1, P ≤ 0.05) but had no consistent effect on seed protein concentration. Lentil or pea crop history among locations did not explain inoculant response. Inoculant formulations (seed coat vs soil applied) and K fertilizer had inconsistent and small effects on seed yield and protein concentration. However, S fertilizer (5.6 kg S ha−1) increased seed yield in 4 of 20 experiments (P ≤ 0.02) by an average of 14.5% (255 kg ha−1) in those experiments and decreased seed yield for one experiment (P = 0.05) by 5.8% (153 kg ha−1). Pre‐plant SO4‐S soil test levels did not predict lentil response to S fertilizer. Micronutrient application was assessed in 12 location‐years but had no effect on lentil yield or protein concentration. This research suggests a need to better understand what factors control lentil yield and protein response to rhizobial inoculant and S fertilization.This article is protected by copyright. All rights reserved