ABSTRACT
Summary Alfalfa (Medicago sativa L.) is the most important perennial forage legume grown in Pennsylvania. However, yields currently reported by farmers are considerably below what might be expected when all production inputs are utilized. Therefore, a program was developed (1) to measure how much alfalfa hay, protein, and energy can be produced on 1 ha of Pennsylvania land under nonirrigated conditions, (2) to determine the mineral content and uptake by high-yielding alfalfa crops, and (3) to obtain more realistic on-farm estimates of alfalfa production costs. To achieve the program goals, hay production for each harvest from 2.02-ha farm fields was estimated, using a method developed specifically for this program. Forage samples were taken at the same times and analyzed for quality and mineral content. Cost-of-production estimates were compiled from enterprise budgets prepared by each grower. The average estimated yield for each of the four years of the program ranged from 12.3 to 13.0 metric tons (t)/ha (10% moisture) with the highest yield approximately 2½ times the lowest yield each year. The highest estimated production during the 4 years was: hay, 20.4 t/ha; crude protein, 3,898 kg/ha; and total digestible nutrients 11,648 kg/ha. Mineral analysis of the forage samples indicated significant farm-to-farm and year-to-year variations in mineral content. Nevertheless, for the most part the values were in the normally expected range, and virtually no relationship was found between mineral content and yield. Annual mineral uptake also showed considerable variation. For example, P and K uptake ranged from 22 to 72 and from 162 to 624 kg/ha, respectively. The average anuual mineral uptake for P, K, Ca, Mg, and S was 41, 355, 147, 25, and 27 kg/ha, respectively. Average estimated annual production costs compiled for the 4 years of the program increased from $429 to $656/ha while the average net return decreased from $401 to $302/ha. The break-even yield during the period jumped from 6.3 to 8.3 t/ha, approximately 14%/yr, emphasizing the need for optimum yields to assure satisfactory returns. The major factors in the annual costs of production were: machinery, 39%; fertilizer and lime, 20%; labor, 17%; and land, 17%. Other production costs, including seed, spray materials, etc., totaled only 7%. The Pennsylvania Alfalfa Growers Program has clearly shown the potential for higher production and greater profitability for alfalfa growers in the state through application of proven production practices and control of unnecessary production costs.
