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Fluid Journal : Fluid Journal 1993-1995
1 Fluid Journal Fall 1994 Summary: Using a systems approach friendly to the environment, a three- crop/two-year no-till system has shown significant yield increases in a three- year FEE-sponsored research project conducted at the Poplar Hill Research and Education Facility in Quantico, Maryland. In each case, corn, wheat, and double-cropped soybean yields exceeded average yields obtained by top farmers in Maryland's Delmarva Peninsula. Instrumental in producing these superior yields were enhanced fertility, supplemental water, and appropriate variety selection. A popular rotation in the mid- Atlantic states includes corn, wheat, and double-cropped soy-beans. The three-crop/two-year rotation is ideally suited to the soils and climate of the area. Heavy users of the three crops are large livestock and poultry industries in the region. Research into increasing production levels of these crops is deemed useful because all three must be imported into this grain-deficit region to meet feed needs. We began studying ways to improve wheat production in 1980 and have been able to produce yields over 100 bu/A each year, regardless of weather patterns. Other maximum economic yield (MEY) studies on corn and soy-beans have proven successful. In our three-year study, we have found that these higher yields can be profitably produced in cropping systems that protect the environment. Exceeding average As can be seen in Figure 1, the crops grown using the systems approach significantly outyielded averages in the Delmarva Peninsula. Corn. Although the three-year aver-age for corn yield did not reach our MEY goal of 250 bu/A, it was almost double the average of the Delmarva Peninsula and significantly greater than that produced by top farmers. Wheat Again, wheat yield fell short of our MEY goal of 125 bu/A, but, like corn, almost doubled the average of the Delmarva Peninsula and was significantly greater than that produced by top farmers. Many farmers are adopting the intensive wheat management system. Record state average yields the past two years reflect this change. Soybeans. The '91 field-size systems study produced a yield below our MEY goal of 65 bu/A but was substantially higher than the peninsula average and 5 bu/A better than that of top farmers. Farmer yields with double-cropped soybeans have been historically low because of the relatively short growing season, low moisture supplies, and low fertility. To maximize yields, double- cropped soybeans must be planted as soon as the wheat is harvested, usually during the first week in July. Fine-tuning In our study, variables were looked at by F. Ronald Mulford and Dr. William J. Kenworthy Systems Approach Produces Yield Gains Crop rotations, combined with enhanced fertility, supplemental water, and ap- propriate variety selection, produce significant yield gains. for each crop and those practices proving best for each crop were incorporated. Corn. Ten corn hybrids (five mid- season and five full-season) were planted on May 14 in 15- and 30-inch rows with a final population of 31,000 plants/A. As can be seen in Figure 2, row and hybrid selection made a significant difference in yield results. Only the top and bottom hybrids are shown in the figure. Eight of the ten hybrids averaged over 10 bu/A more when planted in 15-inch rows. The fertilization program used for corn is shown in Table 1. Soil test levels for P and K were high in the plot area. The goal here was to apply the right amounts of nutrients at the optimum time for the most efficient plant uptake. Wheat Factors we've found important to consistently high yields are 1) selection of high-yielding/disease resistant varieties, 2) following planting recommendations, 3) bringing nutrient levels into high range via soil testing, 4) scouting to control weeds, insects and diseases, 5) using a growth regulator in combination with split N applications when needed, and 6) strict N management, including rate, source, and timing. Table 1. Corn fertilization program for a three-crop/two-year rotation system, Mulford/Kenworthy, Maryland. Application time N P2O5 K2O S BMnZnCu and method lbs/A Preplant broadcast 60 40 40 20 6 2 2 With herbicide- preemergence 1 Sidedress- 5-leaf 110 20 60 10 Sidedress- row closer 70 20 60 10
Fluid Journal 1996-1998