Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-27T10:17:07.240Z Has data issue: false hasContentIssue false

Comparison of harvest techniques for corn field demonstrations

Published online by Cambridge University Press:  30 October 2009

Charles A. Shapiro
Affiliation:
Assistant Professor in Agronomy at the Northeast Research and Extension Center, Concord, NE 68787.
William L. Kranz
Affiliation:
Assistant Professor in Agricultural Engineering at the Northeast Research and Extension Center, Concord, NE 68787.
Anne M. Parkhurst
Affiliation:
Professor of Biometrics, University of Nebraska, Lincoln, NE 68583.
Get access

Abstract

On-farm field demonstrations provide a useful method of technology transfer for researchers and extension specialists, and the proponents of alternative agriculture have adopted on-farm experimentation as an important means to establish the value of sustainable methods. For on-farm research long narrow strips harvested by machine are often employed in place of small hand-harvested plots commonly used at research facilities. The use of this approach, however, could bring the methodology into question if field variation should make determination of statistical differences difficult. Analysis of harvest data from ten irrigated and four dryland site-years for small hand-harvested corn plots and for machine-harvested long narrow strips was conducted to determine the impact of sampling method upon experimental variation. Analyses of variance indicated that six of the ten machine-harvested irrigated sites had significant yield response to applied nitrogen while only one of the ten hand-harvested sites exhibited significant nitrogen effects (P ≤ 0.10). The difference in statistical precision was not a result of increased range in yields, but rather of more consistent yields for each treatment. An economic analysis was performed, and the results indicated that optimum nitrogen rates depended on corn and nitrogen price ratios. When 1989 corn and nitrogen prices were used, the calculated marginal profit levels between the reduced nitrogen and recommended nitrogen rate ranged from $8.92 to -$8.14 per ha. For the irrigated sites, when experimental variation (F-test of total sum of squares) was compared by harvest method, hand harvest had significantly greater variation than machine harvest in five experiments. Machine harvest was significantly more variable in one comparison. Coefficients of variation for machine harvest were less than for hand harvest in nine of ten irrigated experiments. For the dryland sites, differences between harvest methods were significant in one of four experiments. These data suggest that under certain conditions machine-harvested long narrow strips provide more accurate estimates of treatment differences than do small hand-harvested plots despite potential differences in soil texture, soil fertility, or available soil water.

Type
Articles
Copyright
Copyright © Cambridge University Press 1989

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Fleming, A. A., Rogers, T. Hayden, and Bancroft, T. A.. 1957. Field plot technique with hybrid corn under Alabama conditions. Agron. J. 49:14.CrossRefGoogle Scholar
2.Francis, C. A., Parkhurst, A. M., and Thompson, R.. 1986. Designs for on-farm research: Statistical rigor and client credibility. In Agronomy Abstracts, ASA, Madison, Wisconsin, p. 111.Google Scholar
3.Gilbert, E. H., Norman, D. W., and Winch, F. E.. 1980. Farming systems research: A critical appraisal. MSU Rural Development Paper No. 6, Dept. of Agricultural Economics, Michigan State University, East Lansing, Michigan.Google Scholar
4.Havlin, J., and Elmore, R.. 1984. Maximizing the use of farm strip plots. NebGuide G84–723. University of Nebraska, Lincoln, Nebraska.Google Scholar
5.Jose, D. H., Bitney, L. L., Clark, R. T., Duey, D. D., Klein, R. N., Mohrmann, J. R., Powell, T. A., Robb, J. G., Selley, R. A., Sheffield, L. F.. 1989. Estimated crop and livestock production costs. University of Nebraska, Lincoln, Nebraska, p. D15.Google Scholar
6.Lockeretz, W. 1987. Establishing the proper role of on-farm research. Amer. Jour, of Alter. Agric. 3:132136.CrossRefGoogle Scholar
7.Martinez, J. C., and Arauz, J. R.. 1984. Developing appropriate technologies through onfarm research: The lesson from Caisan, Panama. Agricultural Administration 17:93114.CrossRefGoogle Scholar
8.Rzewnicki, P. E., Thompson, R., Lesoing, G. W., Elmore, R. W., Francis, C. A., Parkhurst, A. M., and Moomaw, R. S.. 1988. On-farm experiment designs and implications for locating research sites. Amer. Jour, of Alter. Agric. 3:168173.CrossRefGoogle Scholar
9.SAS Institute, Inc. 1985. SAS User's Guide: Basics, Version 5 Edition. SAS Institute Inc., Cary, North Carolina.Google Scholar
10.SAS Institute, Inc. 1987. SAS/STAT Guide for Personal Computers, Version 6 Edition. SAS Institute, Inc., Cary, North Carolina, pp. 549641.Google Scholar
11.Steel, R. G., and Tome, J. H.. 1980. Principles and procedures of statistics. Second Edition. McGraw-Hill Book Co., Inc., New York, New York. pp. 132133.Google Scholar
12.Thompson, R. 1986. A farmer's approach to on-farm research design. Mimeo. Practical Farmers of Iowa, Boone, Iowa.Google Scholar
13.Wolkowski, R. R., Reisdorf, T. A., and Bundy, L. G.. 1988. Field plot technique comparison for estimating corn grain and dry matter yield. Agron. J. 80:278280.CrossRefGoogle Scholar