For many years, Auburn University has been at the forefront of stocker cattle grazing system research. Numerous studies have been conducted comparing average daily gains and animal gains per acre with various forages and forage systems. Auburn Extension Forage Specialist Don Ball and Extension Economist Walt Prevatt recently completed a detailed summary of 37 grazing studies in which they compared pasture costs per pound of stocker gain for each of these different pasture forage systems. Total pasture costs per pound of stocker gain ranged from $.30 to $1.49. Of the top ten lowest cost forage systems, eight included legumes alone or in pasture mixes of fescue, orchardgrass or winter annuals. The two lowest cost grazing systems were tall fescue with ladino clover and orchardgrass with ladino clover. The researchers cited (1) improved forage quality and (2) the reduction in the amount of nitrogen fertilizer needed as key advantages of the lowest cost grazing schemes.
Doctors Ball and Prevatt also reported the significant effect toxic fescue has on cost of gain compared to non- toxic fescue. They found that “in general, the higher the percentage infestation by toxic endophyte in tall fescue, the more costly the gains”. They reported that among treatments at the Black Belt Research Center, the total pasture cost/lb. of gain was almost double ($1.12 vs. $.65) in the high versus low endophyte treatments.
These findings support numerous stocker cattle studies done more recently with Jesup MaxQ non-toxic, novel endophyte tall fescue and/or Durana or Patriot white clovers. Trials across the country have shown significant improvements in animal gains and gains per acre when these forages were used in the grazing system.
LOW SOIL PH REDUCES FERTILIZER EFFICIENCY
Failure to maintain soil pH at proper levels decreases fertilizer efficiency resulting in lower yields and wasted money. Uptake of the major soil nutrients – nitrogen, phosphorus and potassium – is optimized at a soil pH range of 6.3 to 7.0. When the soil pH drops below this range, N, P & K uptake efficiency is reduced.
According to UGA Extension Forage Agronomist Dennis Hancock, nutrient uptake efficiency on soil with a pH of 5.6 is reduced 35% for N, 50% for P and 10% for K when compared to uptake at a soil pH of 6.2. For hayland, this can result in lost fertilizer value totaling $60 or more per acre annually (see table).
In most areas of the country, the prorated annual cost of aglime needed to raise a pH of 5.6 to 6.2 would approximate $15/acre or less. Keeping in mind potential yield loss, wasted value of fertilizer applied and the positive economics of applying lime, one can easily see the significant benefits of maintaining proper soil pH in pastures and hay fields.