Seeding and nitrogen fertilization effects on the yield and quality of brachytic dwarf brown midrib forage sorghum hybrids

Abstract

Brown midrib (BMR) forage sorghum [Sorghum bicolor (L.) Moench] silage is an alternative to corn (Zea mays L.) silage for areas with limited soil moisture. Traditional forage varieties are tall and prone to lodging, with low forage quality. Brachtyic dwarf BMR lines are shorter and lodging‐resistant and have higher forage quality. Newer earlier‐maturing hybrids have expanded the potential adaptation of forage sorghums to northern latitudes. A 2‐yr study was conducted during the 2014 and 2015 growing seasons with brachytic dwarf BMR forage hybrids to determine the effects of different seeding and N fertilization rates on forage dry matter yield and quality. The experimental design was a split‐split‐plot with four replications. The main plots were two hybrids (‘AF7202’ and ‘AF7401’), the subplots were two seeding rates (80,000 and 120,000 seeds acre−1), and the sub‐subplots were two N rates (110 and 150 lb acre−1). Significant differences were observed between hybrids for all parameters except neutral detergent fiber digestibility (NDFD) in 2015. The early hybrid, AF7202, had higher yields and higher starch content and net energy for lactation levels than dwarf hybrid AF7401 and was more responsive to higher N. AF7401 had higher crude protein content and NDFD. Crude protein increased as N level increased for both hybrids but other forage quality traits were unaffected. Neither variety responded to an increased seeding rate. The earlier brachytic dwarf forage sorghums, such as AF7202, managed with recommended seeding rates and possibly higher N rates, have potential for high forage yield and quality in central Pennsylvania.

Nitrogen fertilizer source, rate, placement, and application timing effect on sorghum (grain and forage) and corn grain yields

“…Environment-dependent fertilizer rate response in forage sorghum was in agreement with other studies. Elango et al (2020) reported N response from forage sorghum in a year with seasonal rainfall of 333 mm precipitation, and no N response in a year with 450 mm precipitation. Haankuku et al (2014) also reported no response of forage sorghum to application of N fertilizer in drought years at two siteyears.…”

“…Elango et al. (2020) reported N response from forage sorghum in a year with seasonal rainfall of 333 mm precipitation, and no N response in a year with 450 mm precipitation. Haankuku et al.…”

Seeding Rate Effects on Forage Mass and Vegetation Dynamics of Cool-Season Grass Sod Interseeded with Sorghum-Sudangrass

“…Research under limited irrigation in New Mexico, however, indicated there was no effect of planting rate on DM yield or nutritive value of conventional and brown midrib forage sorghum grown for silage [11]. Seeding rate also had no effect on DM yield and quality of brachytic dwarf, brown midrib lines of forage sorghum hybrids in Pennsylvania [12]. In Ethiopia, increasing seeding rate increased forage quality, but did not affect DM accumulation of two dual-purpose grain sorghum varieties and one traditional local variety [13].…”

Association genetics of early season cold and late season frost tolerance in Sorghum bicolor

“…In the USA, sorghum is primarily used as animal feed (Rhodes et al, 2017), though increasingly being exploited as an alternate source of bio-energy (Xin & Wang, 2011). Sorghum utilizes water and nitrogen fertilizers more efficiently than maize and is generally better adapted to drought, heat, and salinity and also grows on the same climatic range as maize with comparable nutritive values (Elango et al, 2020a;Elango et al, 2020b;Howell et al, 1993Howell et al, , 2008Lamm et al, 2007;Martin, 1930;Merrill et al, 2007;Prasad et al, 2018). USA remains the world leader in sorghum export, farmers planted 5.6 million acres of sorghum and harvested 9.2 million metric tons of sorghum grain in 2017.…”