Sign up for email alerts of new Fluid Journal issues!
Fluid Journal : Fluid Journal 2002-2004
Spring 2004 Fluid Journal 2 Table 3. Economic returns from three soil fertility practices on 'Lockett' wheat in a graze-plus-grain management program during three years at Vernon, Texas. N surface NP surface NP deep 2003 Mean* 2003 Mean 2003 Mean ------------------ --- --- ------dollars/A--- --------------------------- --- Income Grain 92 74 120 93 109 85 Cattle 20 22 27 26 30 28 FSA 12 17 12 17 12 17 Total 124 113 159 136 151 130 Expenses 92 83 106 95 107 96 Returns** 33 30 53 42 45 34 * Means from three years data. ** Returns to indirect costs, land, and management. little information on fertilizer manage- ment in dual-use wheat/stocker systems. Nitrogen requirements for forage, grain, and that removed by cattle can be estimated. However, the amount of P to be applied is less readily determined. Studies have shown that for acid soils in the southern plains of Oklahoma, broadcasting lime before the initial season and placing 65 lbs/A of diammonium phosphate in the seed furrow each year proved the most economical strategies for dual-use wheat production over five years (to amortize the cost of lime). In wheat trials in the southern Great Plains of Texas, deep placing P increased wheat forage yields 50 percent more than surface-applied P, and 45 percent more than the same rate of N but no P. There is little question that application of P to P-deficient soils will increase both grain and forage yields. Objectives of this study were to 1) determine the influence of P fertilizer and P fertilizer placement on forage, beef, and grain production from dual- purpose wheat, 2) determine grazing termination dates effects on grain yield and animal performance, and 3) identify economic costs and returns associated with P fertilizer and P placement methods and length of grazing period of winter wheat in the Texas Rolling Plains. Forage gain P fertilizer applications increased wheat forage production each year of the study, with the greatest percentage increase occurring during the first grazing phase or prior to March 1. Data in Table 1 indicate that P applications increased forage production 55 percent (630 lbs/A) and 26 percent (740 lbs/A) before and after March 1, respectively. On an annual basis, P increased forage production 35 percent or nearly 1,400 lbs/A. Furthermore, response to P increased each year of the study. Although fall forage production is especially important to stocker cattle programs in the Southern Great Plains, the season-long increase in production is also very valuable but less recog- nized. It is apparent that deep placement of fertilizers gave no advantage over surface applications followed by incorporation. However, location of knife rows could be identified visually in late fall by the larger, darker green wheat plants. Gain per head Because we attempted to keep forage allowance uniform among all pastures in the experiment, animal gain per head per day (ADG) and gain per head would be expected to be the same in all pastures. Animal gain per acre should reflect the difference in forage produc- tion among pastures through higher stocking rates and thus more gain per acre in pastures with more forage production. Data in Table 2 show that ADG and gain per head were very similar among treatments. P applica- tions increased average animal gain by 23 lbs/A or 32 percent during three years in the grazing phase prior to March 1. Increased gains per acre were statistically significant in only 2001 to 2002. During the three years, grain yields were not significantly increased by P fertilization, although yields increased as much as 9 bu/A in 2003. Bottom line An enterprise budget was created for each replication of each fertilizer treatment in order to compare economic returns within each grazing manage- ment system. Table 3 contains income, direct expenses, and returns for the three fertilizer practices in the graze-plus- grain system. Three-year means show that where no P was applied, income averaged $113 per year while income averaged $136 and $130 per year where P was surface applied and knifed, respectively. Direct expenses were similar among treatments except that P application increased costs by roughly $12/A. Returns of $34 to $42/A where P was applied, compared to $30/A without P, largely reflect the increased income resulting from applied P. In 2003, returns were more favorable but trends were similar. The returns do not include indirect expenses or the costs of land and management. Dr. Robinson is professor and resident director, Texas Agricultural Experiment Station (TAES), Vernon; Dr. Sij is agronomist, TAES, Vernon; Dr. Pinchak is animal nutritionist, TAES, Vernon; Dr. Gill is livestock specialist, Texas Cooperative Extension (TCE), Dallas; Dr. Malinowski is forage agronomist, TAES, Vernon; Dr. Baughman is agronomist, TCE, Vernon; and Mr. Bevers is agronomist, TCE, Vernon; with the Texas A&M University System.
Fluid Journal 1999-2001
Fluid Journal 2005-2007