Nitrogen fertilization is a common practice for sustaining forage production in forage systems in southeastern United States. Warm‐season annual legumes may be an alternative forage to warm‐season perennial grasses that do not require N fertilization. Sunn hemp (Crotalaria juncea L.) is a fast‐growing, warm‐season annual legume native to India and Pakistan. The objective of this 2‐year study was to assess the herbage accumulation (HA), atmospheric N₂ fixation (ANF) and nutritive value of sunn hemp. Treatments were the factorial arrangement of two sunn hemp cultivars (“Crescent Sun” and “Blue Leaf”), three seeding rates (17, 28 and 39 kg seed/ha) and seed inoculation (inoculated or non‐inoculated seeds), distributed in a randomized complete block design with four replicates. Crescent sun had greater HA (3,218 vs. 1764 kg DM/ha) and ANF (41 vs. 25 kg N/ha). Blue leaf had greater crude protein (CP) (188 vs. 176 g/kg) and in vitro digestible organic matter (IVDOM) concentrations (564 vs. 531 g/kg) than crescent sun. Non‐inoculated seed had greater CP than inoculated seed, 188 and 177 g/kg, respectively, and inoculation did not affect HA. Intermediate seeding rate (28 kg/ha) decreased HA (2002 kg DM/ha), while HA from high and low seeding rates (17 and 39 kg/ha, respectively) did not differ (2,863 and 2,615 kg DM/ha respectively). Planting non‐inoculated crescent sun at 17 kg/ha seeding rate is a feasible management practice to produce sunn hemp in subtropical regions; however, inoculation should always be recommended for proper establishment.

中文翻译：

---

建立技术会影响两个麻麻品种的生产力，营养价值和大气固氮

氮肥施用是维持美国东南部饲草系统中饲草生产的一种普遍做法。暖季一年生豆科植物可以替代不需要氮肥的暖季多年生禾草。n麻（Croctalaria juncea L.）是一种生长迅速，暖季的豆类，原产于印度和巴基斯坦。这项为期2年研究的目的是评估大气中N ₂的牧草蓄积量（HA）麻的固着（ANF）和营养价值。处理方法是将两个逊麻品种（“新月”和“蓝叶”），三个播种量（17、28和39 kg种子/公顷）和种子接种量（接种或未接种种子）分解配置。具有四个重复的随机完整块设计。新月形太阳具有更高的HA（3,218比1764 kg DM / ha）和ANF（41比25 kg N / ha）。与新月相比，蓝叶的粗蛋白（CP）（188 vs. 176 g / kg）和体外可消化有机质（IVDOM）浓度更高（564 vs. 531 g / kg）。非接种种子的CP值大于接种种子的CP，分别为188 g / kg和177 g / kg，接种不会影响HA。中度播种量（28 kg / ha）降低了HA（2002 kg DM / ha），而高和低播种率（分别为17和39 kg / ha）的HA没有差异（2，分别为863和2,615千克DM /公顷）。以17 kg / ha的播种量播种未接种的新月形太阳是在亚热带地区生产management麻的可行管理方法。但是，应始终建议进行正确的接种。