Illinois
Fertilizer Conference Proceedings
January 28-30, 1991
| Home | 1991 Index | Search |
| Home | 1991 Index | Search |
Ted R. Peck1
With the current economic cost-price squeeze of crop production inputs, such as liming materials and fertilizers, with commodity prices, environmental concerns, and availability of computerized field spreading equipment, there is need to better understand soil fertility spacial patterns in fields that affect crop yields.
Two 40-acre. fields are involved in this study. This study is a three-part program. Part one is to sample each field on a 16x16 grid to develop maps of soil fertility, plant composition and crop yield. Part two is to adjust field one with a liming program to an optimum level and field two with a P and K fertilizer to an optimum level. Part three is to evaluate the effects of adjustment by repeating part one.
Field 1 is located near Mansfield and field 2 near Thomasboro, Illinois. Field 1 was cropped to soybeans in 1990 that was damaged by late spring rains so about 20 percent of the field died. Soil samples were collected in late November. Field 2 was cropped to corn in 1990 with some water damage resulting in "Crazy Top" but plant samples were collected at two growth stages, grain yields measured, and soil samples collected. This project was funded August 20,1990 to support a Ph.D. program which David Franzen has accepted. Samples previously mentioned are being processed.
Differences in crop yields within a field are well known. The extent to which causes of crop yield variation are related to soil conditions are well accepted but unproven as to manageability and economics of management. Crop production in areas of low fertility might benefit from additional fertilization and savings might be realized with reduced fertilization of high soil fertility. Future environmental regulations might necessitate greater precision and accuracy of nutrient application. In addition, the concept of localized application needs to be evaluated.
This study is a three part program planned for a six-crop-year project. Part one is to map field soil fertility conditions, crop plant nutrient composition, crop yield and develop relation among these factors. Part two is to adjust field soil fertility levels to optimum. Pact three is to evaluate effects of field adjustment by repeating part one. Since funding did not become available until August 20,1990, and weather was unfavorable for normal growth to allow mapping plant composition, and yield in Field 1 and Field 2 had limitation of disease in 1990, it is anticipated 1991 will be devoted to more completely characterizing the two fields. We will do soil sampling in the fall and testing, plant sampling whole plants in early season and selected leaves at midseason, testing, and yield checks, on a systematic 5-rod sampling grid, which is a 16x16 grid that gives 256 data points in a 40-acre field.
A partial data base already exists for both fields. Both fields are University of Illinois property managed by the farm management department of the Agricultural Economics Department, University of Illinois.
Field 1 is located near Mansfield, Illinois in Piatt County. This field was soil sampled with the systematic 5-rod grid in 1961, 1976, 1982, 1988, 1989 and 1990. Partial corn yield data were obtained in the fall of 1989, but due to severe lodging from high wind damage, this data is of limited usefulness. Records of field average agricultural limestone, nitrogen, phosphorus, and potassium fertilizer additions and crop yields on an annual basis are known and accessible. Cropping plans for the future are for annual alternation of corn and soybeans with corn planted in 1991 and the east 15 percent in set aside. This field is targeted for localized application of agricultural limestone on acid soil areas to "standardize" the soil pH to near 6.2.
Field 2 is located near Thomasboro, Illinois in Champaign County. This field was not farmed (or very little) from 1940 through 1982, being left to grow native grasses that may have been occasionally harvested for hay. Soil samples have been collected on a systematic 5-rod grid in 1982, 1986, 1987, 1988, June 1989, October 1989, and 1990. Whole plant samples have been collected at the early growth stage in 1988, 1989, and 1990 and ear leaves at the mid-season growth stage in 1989 and 1990. Partial corn yield data have been collected in 1988, 1989 and 1990. Severe drought in 1988 and wetness induced "Crazy Top" disease limits the usefulness of this data. This field is scheduled to be cropped to continuous corn as it has been since 1983. This field is targeted for localized applications of phosphorus and potassium fertilizer on low P and K areas to "standardize" the P and K areas to optimum conditions.
Both fields have been residual with respect to agricultural limestone, P, and K fertilizer application since the last application in the fall of 1986.
Soil type maps and soil fertility maps for the 1989 soil sampling are shown in Figure 1 for the Mansfield Tract and Figure 2 for the Thomasboro Tract.
As this project was initiated in the late summer of 1990, no research results are available at the date of this report. David Franzen, candidate for Ph.D. program in the Department of Agronomy, has accepted this program for his Thesis Project.
No summary is available at this time
