Harvest management and genotype effects on sunn hemp forage characteristics

Abstract

Sunn hemp (Crotalaria juncea L.) is an annual legume widely used as cover crop; however, there is potential to use it as forage. The objective of this study was to evaluate forage characteristics of 5 sunn hemp genotypes (HA, nutritive value, N fixation and nematode control), and beef heifer responses (intake and digestibility) to sunn hemp dietary inclusion. Two experiments were conducted at Ona, FL in 2016 and 2017. In Exp. 1, treatments were the factorial arrangement of five sunn hemp genotypes (AU Golden, Crescent Sunn, Ubon, This article is protected by copyright. All rights reserved. Blue Leaf and Red Mini) and two harvesting time (60 d after seeding or flowering) in a randomized complete block design. In Exp. 2, treatments were 100% sun hemp hay, 50% sunn hemp-50% bermudagrass [Cynodon dactylon (L.) Pers] hay, or 100% bermudagrass hay diets distributed in a completely randomized design. In Exp. 1, Crescent Sunn had the greatest HA [15.2 Mg dry matter (DM) ha-1 ], N fixation (81 kg N ha-1) and nematode control (80% reduction). AU Golden had the greatest crude protein (CP) concentration at 60 d after seeding and flowering (155 and 162 g kg-1 , respectively). In Exp. 2, increasing the proportion of sunn hemp in the diet decreased total forage DM intake (1.6, 1.4 and 1.2 as a % bodyweight with 0, 50 and 100% sunn hemp inclusion). Sunn hemp harvested 60 d after seeding is adequate to meet the nutritional requirements of most beef cattle categories but the genotype choice affects HA and nutritive value.

Sunn hemp planting date effect on growth, biomass accumulation, and nutritive value in southeastern Wyoming

“…Biomass accumulation ranged for 0.2-5.1 Mg ha −1 in the rainfed study and 1.2-4.2 Mg ha −1 in the irrigated study, which is comparable to reported yields for sunn hemp. Schomberg et al (2007) found that at 60 DAP sunn hemp biomass yielded 4.6 and 5.0 Mg ha −1 at their locations in Tiffton, GA, and Watkinsville, GA. Cherr et al (2006) reported sunn hemp yields of 4.0 Mg ha −1 at 60 DAP in Citra, FL, and Garzon et al (2020) found biomass yield from 1.0 to 3.3 Mg ha −1 at 60 DAP in Ona, FL. Our biomass accumulation falls within the reported ranges for southern growing locations where the crop is typically grown.…”

Characterization of Green Manure Sunn Hemp Crop Silage Prepared with Additives: Aerobic Instability, Nitrogen Value, and In Vitro Rumen Methane Production

“…The data suggested that it has a moderate level of soluble TPN fraction (179 g/kg total N), which was approximately equal to that of a haft of oats (430 g/kg total N) [26]. The nutritive value of an SH crop can vary among genotypes and as a result of other factors such as soil, fertilizer, and weather [1].…”

“…Sunn hemp (SH, Crotalaria juncea, L.) is an annual legume originating from India [1]. This plant species grows fast, has high seed yield, is tolerant of low fertilizer conditions, and is easily harvested or plowed into soil.…”

Assessment of Seed Yielding Potential of Sunnhemp (Crotalaria juncea) under Southern Plateau Zone of India

“…It finds uses in industry as a source of paper-pulp, currency paper, cigarette paper, tissue paper etc. This crop has the potential to be used as a forage crop (Burke et al, 2011;Garzon et al, 2020) on account of higher biomass of its foliage (Cho et al, 2015) and availability of essential nutrients in its feedstock (Cantrell et al 2010). It has the potential of reducing use of synthetic chemicals from agricultural system.…”