13 Stockpiling Bahiagrass to Extend the Grazing Season and decrease Winter Supplementation Costs for South Alabama Cattle Producers

Abstract

Abstract Stockpiling forage is a management practice that can be used to decrease the cost of winter cow supplementation and is defined as the process of accumulating forage late in a growing season for grazing at a later date. The purpose of this study was to explore the effectiveness of bahiagrass as a potential stockpiled forage in lower Alabama by developing a better understanding of its forage accumulation, nutritive value and persistent characteristics during the stockpiling period (6 to 10 weeks). A small-plot stockpiling trial was conducted at three locations in south Alabama (Troy, Headland, and Goodway). Nine, 6.5 m x 2.0 m plots were cut to a 7.5 cm stubble height with a buffer of 0.9 m between plots at each location beginning on September 16, 2021. Nitrogen fertilization strategy was the main plot [0 N fertilizer, split N application (33.6 kg N/ha at initiation and again 30 d later), or 67.2 kg N/ha; 3 replications/treatment; N source = urea (46-0-0)]. Stockpiling period length was the split-plot (6, 8 or 10 weeks of forage accumulation; n = 9 subplots/treatment). Response variables were measured including forage mass and nutritive value at 6, 8 and 10 weeks, and nutritive value of standing forage 30 days after the stockpiling period. Data were analyzed using the PROC MIXED procedure of SAS 9.3. As the accumulation period length increased, average forage mass increased across all treatments with 1,312.6 kg DM/ha at 6 weeks, 1,270.1 kg DM/ha at 8 weeks and 1,585.9 kg DM/ha at 10 weeks. With respect to the fertilization treatments, the split N application (1,621.8 kg DM/ha) and 67.2 kg N/ha fertilization strategies (1,606.1 kg DM/ha) did not differ in forage accumulation but were greater (P < 0.05) than bahiagrass not receiving N fertilizer (1,377.6 kg DM/ha). For nutritive value, nitrogen application strategy impacted bahiagrass crude protein (CP), with both the split N application (14%) and 67.2 kg N/ha (13.8%) treatments having a greater CP (P < 0.05) than the 0 N fertilization approach (11.7%). Average total digestible nutrients across stockpiling periods were 62.5%. Year one results study indicate that bahiagrass may support forage production and nutritive value for cow-calf operations wanting to extend grazing into the fall and early winter months in the Southeast US. Based on year one results for forage mass measured at 6, 8 and 10 weeks, stockpiled bahiagrass could provide an estimated 45 to 55 days of grazing depending on mature cow weight, pasture stocking strategy and accumulation period length.