Boron Fertilization of Irrigated Alfalfa in Montana

Abstract

Core Ideas Boron (B) application increased petiole B in irrigated alfalfa but did not impact yield and quality. Low initial soil B is not a reliable measure of the need to amend with B using foliar application of irrigated alfalfa in Montana. Diagnosing signs of B deficiency coupled with in‐season petiole B analysis may be of better value to the producers. A boron (B) deficient soil may negatively impact irrigated alfalfa (Medicago sativa L.) plant tissue sufficiency, thereby compromising yield and quality in a short‐season environment such as Montana. The objective was to determine the impacts of B fertilization on irrigated alfalfa yield and quality in 2015 and 2016 at Creston and Dillon, MT on fine sandy loam and silt loam soils, respectively. The initial soil B levels at the Creston and Dillon sites were 0.2 and 0.8 ppm, respectively. The study was conducted as a randomized complete block design with five B levels: (1) 0; split applications of (2) 0.50, (3) 1.00, (4) 2.00; and a one‐time application of (5) 2.00 lb/ac in four replications. Full doses of Treatment 5 and half the dose of Treatments 2–4 were applied in early spring at a 3‐inch regrowth height. The other half dosage of Treatments 2–4 was re‐applied at a 3‐inch plant height after the first cutting. A liquid 10% B AgriSolutions was foliar‐applied as B fertilizer. All the cuttings were performed at 10% bloom. Application of B increased (P < 0.05) plant B concentration at both locations. Boron fertilization increased (P < 0.05) crop yield for the second cutting in 2015 at Dillon but did not influence all of the other seasonal cuttings nor total yields for either year or location. No significant effect of B on forage quality was observed. This research suggests foliar B fertilization based on a low B soil test is not beneficial for irrigated alfalfa producers in Montana.

Applied Boron Increases Alfalfa Petiole Boron Concentration across Water Regimes, Not Yield

“…Overall, the effect of B on total yield was nonsignificant in northwestern Montana, similar to reported findings in literature (Grant and Miller, 1998; Pecinovsky and Lang, 2012; Razmjoo and Henderlong, 1997; Sapkota et al, 2017, 2018). Razmjoo and Henderlong (1997) found that application of B up to 2 kg ha −1 did not affect alfalfa yield in Columbus, Ohio on a Crosby silty clay loam soil.…”

“…Razmjoo and Henderlong (1997) found that application of B up to 2 kg ha −1 did not affect alfalfa yield in Columbus, Ohio on a Crosby silty clay loam soil. Similary, Grant and Miller (1998) and Sapkota et al (2018) reported no increases in alfalfa yield with increased B rate applications. Our recent study documented that the B uptake of alfalfa (i.e., 0.06–0.08 kg B Mg −1 production in reference to the control treatment, Fig.…”

“…Treatments of 100% evapotranspiration (100ET) and 50% evapotranspiration (50ET) were included to evaluate alfalfa response to B under nonwater‐stressed (100ET) and simulated water‐stressed treatments, respectively. The B treatments (amount and time of application; Table 2) were adapted from Sapkota et al (2018). Each of the experimental units dimension was 3.1 by 4.6 m, with a 1.5‐m alley between replications and around the experimental plots to allow easy access for plot maintenance and harvest.…”

Boron Toxicity and Deficiency in Agricultural Plants

“…The performance of numerous agricultural plants was improved using boron fertilizers, most importantly in terms of yield, but also in terms of quality and certain physiological parameters, e.g., water management and chlorophyll content. Given the narrow range between deficiency and toxicity, the dosage of the added boron should be carefully adjusted for each application [164][165][166][167][168][169][170][171].…”

4R decisions for boron fertilization

“…Cotton grown in greenhouse experiments responded with increased dry matter yield, taller plants, and more reproductive structures per plant as concentration of B in the nutrient solution increased (Bogiani et al, 2014). However, when alfalfa grown in low‐B soils in Montana was fertilized with liquid B fertilizer, there was only a yield response in one cutting out of eight measured over two years and two sites, and quality of the alfalfa hay was not impacted by the applications (Sapkota et al, 2018). Toxicity can happen at low concentrations of B, coffee plants grown in a nutrient solution displayed impacts of B toxicity at a concentration of 0.50 ppm, with death at of the plants at 2.0 ppm B in the solution (Vasco et al, 2018).…”