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© 2003 Plant Management Network.
Accepted for publication 22 May 2003. Published 23 June 2003.

Tillage Effects on Corn Response to Starter Fertilizer

Steven M. Cromley, William J. Wiebold, and Peter C. Scharf, Department of Agronomy, University of Missouri, Columbia 65211

Corresponding author: William J. Wiebold. wieboldw@missouri.edu

Cromley, S. M., Wiebold, W. J., and Scharf, P. C. 2003. Tillage effects on corn response to starter fertilizer. Online. Crop Management doi:10.1094/CM-2003-0623-01-RS.

Abstract

Tillage selection has been identified as a factor that may influence corn response to starter fertilizer. The objective of this experiment was to determine if tillage practices affect corn growth and grain yield response to starter fertilizer. The experiment was conducted near Columbia, MO in 2000 and 2001. The experimental design included three hybrids, with and without tillage and with and without starter fertilizer (30 lb N/acre and 13 lb P/acre), placed 2 inches to the side and 2 inches below the seed. Tillage treatment by starter fertilizer interactions were not significant except for plant height measured eight weeks after planting in 2001. Tillage did not affect corn response to starter fertilizer. No-tillage plots were 5.7 and 3.5 inches taller at 6 weeks after planting than tilled plots in 2000 and 2001. At 8 weeks after planting no-tillage plots were 7.5 and 6.0 inches taller than tilled plots in 2000 and 2001. No-tillage plots reached silking 2.3 and 1.6 days earlier in 2000 and 2001 than tilled plots. Starter fertilizer also affected plant height and silking date, but to a lesser extent than tillage. The effects of starter fertilizer on plant height and crop development never translated into an effect on grain yield. We found no evidence that growers who use no-tillage are more likely to see yield responses from starter fertilizer than growers who use some other form of tillage.

Introduction

No-tillage acreage has increased rapidly during the past 10 years (7). A no-tillage system is one in which no tillage is performed prior to planting of the crop. Advantages of no-tillage include reduced soil erosion, decreased labor, reduced machinery cost, and increased soil water retention (8,10,12).

The increased residue and soil water retention associated with no-tillage can reduce soil temperatures (2,12). This reduction in soil temperature may reduce corn emergence and slow early-season growth (1,3). Use of starter fertilizer may partially offset these detrimental effects because fertilizer is placed near the slowly developing roots (14,15,19). However, few experiments have compared the yield responses from starter fertilizer between no-tillage and conventional tillage. Mengel (18) showed that yield responses to starter fertilizer were much more common in no-tillage than in conventional-tillage systems. Additional research is necessary before appropriate recommendations can be developed. The objective of the experiment was to determine if tillage choice affects corn yield response to starter fertilizer.

Materials and Methods

This experiment was conducted in 2000 and 2001 on a Mexico silt loam soil (montmorillonitc, mesic, aeric, Vertic Epiaqualfs) at the Agronomy Research and Extension Center, near Columbia, MO. Soil pH was 7.0; organic matter was 2%; and P and K soil tests were in the medium range. Soybean [Glycine max. (L) Merr.] was the previous crop. The experimental design was a split-split plot with four replications. Whole plots were two tillage treatments: tilled and no-tillage. Tillage was performed in the spring and consisted of a chisel plow operation followed by a field cultivator. Split plots were three hybrids (Pioneer brand 35N05, 33A14, and 31B13). Split-split plots were the two starter fertilizer treatments: no starter fertilizer and starter fertilizer at a rate of 30 lb N/acre and 13 lb P/acre. Starter fertilizer was a liquid mixture of urea-ammonium nitrate and ammonium polyphosphate.

Plots were planted with a four-row planter equipped with Yetter brand coulters and knives and a CO₂-pressurized tank for starter fertilizer application. The coulters and fertilizer knives were set to place the starter fertilizer 2 inches to the side and 2 inches below the seed. Plots were 50 feet long and four rows wide. Row width was 30 inches. All plots received 160 lbs N/acre as broadcast ammonium nitrate after planting but before emergence. Weeds were controlled with a pre-emergence application of metalachlor and atrazine.

At approximately V4 (20) stand densities were determined and overpopulated plots were thinned to 26,000 plants per acre. Plant height was recorded by measuring to the tip of the tallest extended leaf six and eight weeks after planting. Silking (R1; 20) date was recorded when 50% of the plants had emerged silks at least 0.5 inch in length. Physiological maturity (R6; 20) was recorded when 50% of the kernels exhibited a black layer. The two middle rows were harvested with a plot combine and grain yield was corrected to 15% moisture. Harvest dates were 11 September 2000 and 11 September 2001.

Plant Height

Starter fertilizer significantly increased plant height in both years. Tillage by starter fertilizer interactions were not significant except for plant height eight weeks after planting in 2001. At six weeks after planting, starter fertilizer increased plant height by 1.5 inches in 2000 and 1.9 inches in 2001 (Table 1). The increase in plant height from starter fertilizer was still present eight weeks after planting, but only for the tilled plots (Table 2). Tilled plots treated with starter fertilizer were 3.0 inches taller in both 2000 and 2001 than tilled plots with no starter fertilizer. Increased plant height caused by starter fertilizer has been documented in other studies (5,6,14,17). The three hybrids responded similarly to starter fertilizer with no interactions between starter fertilizer and hybrid.

Table 1. Plant height (inches) measured six weeks after planting of three corn hybrids planted with or without starter fertilizer and with or without tillage.

† Starter fertilizer treatments: No = none; Yes = 30 lb N/acre and 13 lb P/acre.

‡ Means within a year followed by the same letter are not significantly different (LSD_0.05).

Table 2. Plant height (inches) measured eight weeks after planting of three corn hybrids planted with or without starter fertilizer and with or without tillage.

† Starter fertilizer treatments: No = none; Yes = 30 lb N/acre and 13 lb P/acre.

‡ Means within a year followed by the same letter are not significantly different (LSD_0.05).

Tillage selection had a greater effect on plant height than starter fertilizer. Plant height of no-tillage plots six weeks after planting were 5.7 and 3.5 inches greater than plant height of tilled plots in 2000 and 2001 (Table 1). At eight weeks after planting no-tillage plots were 7.5 and 6.0 inches taller than tilled plots in 2000 and 2001 (Table 2). Increased crop growth in no-tillage systems has been documented in previous studies (10,11,13). Hargrove (11) in Georgia observed that root growth and water and nutrient uptake was greater in no-tillage than conventional tillage. He concluded that the increase in water infiltration, storage, and use in no-tillage systems resulted in greater nutrient uptake increasing crop growth. Improved soil structure in no-tillage systems may enhance water and nutrient uptake thus increasing crop growth.

Plant Development

Previous studies have concluded that starter fertilizer often reduces the number of days required for plants to reach silking (9,17). In this study the number of days to reach mid-silk (R1) was reduced by starter fertilizer in 2001, but not 2000. In 2001, plots treated with starter fertilizer reached R1 0.8 days earlier than plots with no starter fertilizer (Table 3). This response was much less than the 3-to-5-day response from starter fertilizer observed by Mascagni and Bouquet (17) in Louisiana.

Table 3. Silking date (number of days after planting) of three corn hybrids planted with or without starter fertilizer and with or without tillage.

† Starter fertilizer treatments: No = none; Yes = 30 lb N/acre and 13 lb P/acre.

‡ Means within a year followed by the same letter are not significantly different (LSD_0.05).

Similar to plant height, tillage selection had a greater effect on silking date than starter fertilizer. Plots in no-tillage systems consistently reached R1 earlier than plots in conventional tillage systems. No-tillage plots reached silking 2.3 days earlier in 2000 and 1.6 days earlier in 2001 than tilled plots (Table 3). No tillage by starter fertilizer or hybrid by starter fertilizer interactions were observed.

Neither starter fertilizer nor tillage affected the number of days to reach R6 in either year. Gordon et al. (9) also observed that starter fertilizer had no effect on the number of days in the grain fill period from R1 to R6.

Grain Yield

Corn grain yield was not affected by starter fertilizer or tillage selection in either year (Table 4). These results agree with a twenty-year study performed in Illinois by Kapusta et al. (13) in which they concluded that starter fertilizer does not increase corn yield within tillage systems. The same study by Kapusta et al. (13) also found that conventional tillage systems out yielded no-tillage systems by 5% to 7% when starter fertilizer was used. Results from our study indicated that corn yields were the same regardless of tillage selection or if starter fertilizer was used. These results do not support previous research by Scharf (21) in Missouri and Buah et al. (4) in Iowa in which they concluded that starter fertilizer increased corn grain yields in no-tillage systems.

Table 4. Yield (bu/acre) of three corn hybrids planted with or without starter fertilizer and with or without tillage.

† Starter fertilizer treatments: No = none; Yes = 30 lb N/acre and 13 lb P/acre.

‡ Means within a year followed by the same letter are not significantly different (LSD_0.05).

Conclusion

Starter fertilizer and tillage selection affected corn growth and development but not yield. Corn yields were the same regardless of tillage selection or starter fertilizer use. Starter fertilizer increased plant height in both years and reduced the number of days for silk emergence in one of two years. Tillage selection had a greater affect on plant height and silking date than starter fertilizer. Plots in no-tillage systems were consistently taller and reached R1 prior than plots in conventional tillage systems. Results from this study agree with previous research that increased early-season growth does not translate into increased grain yield (5,16).

Acknowledgements

Contribution from the Missouri Agriculture Experiment Station. Partial funding for this project was provided by Pioneer Hi-Bred, a Dupont Company.

Literature Cited

1. Al-Darby, A. M., and Lowery, B. 1987. Seed zone temperature and early corn growth with three conservation tillage systems. Soil Sci. Soc. Am. J. 51:768-774.

2. Bennet, O. L., Mathias, E. L., and Lundberg, P. E. 1973. Crop response to no-till management practices on hilly terrain. Agron. J. 65:488-491.

3. Bollera, G. A., Bullock, D. G., and Hollinger, S. E. 1996. Soil temperature and planting date effects on corn yield, leaf area, and plant development. Agron. J. 88:385-390.

4. Buah, S. S. J., Polito, T. A., and Killorn, R. 1999. No-tillage corn hybrid response to starter fertilizer. J. Prod. Agric. 12:676-680.

5. Bundy, L. G., and Andraski, T. W. 1999. Site specific factors affecting corn response to starter fertilizer. J. Prod. Agric. 12:664-670.

6. Bundy, L. G., and Widen, P. C. 1992. Corn response to starter fertilizer: Planting date and tillage effects. Better Crops Plant Food 76:20-23.

7. Conservation Technology Information Center. 2002. National crop residue management Survey. West Lafayette, In.

8. Featherstone, A. M., Fletcher, J. J., Dale, R. F., and Sinclair, H. R. 1999. Comparison of net returns under alternative tillage systems considering spatial weather variability. J. Prod. Agric. 4:166-173.

9. Gordon, W. B., Fjell, D. L., and Whitney, D. A. 1997. Corn hybrid response to starter fertilizer in a no-tillage dryland environment. J. Prod. Agric. 10:401-404.

10. Griffith, D. R., Mannering, J. V., and Moldenhauer, W. C. 1977. Conservation tillage in the eastern corn belt. J. Soil Water Conserv. 32:20-28.

11. Hargrove, W. L. 1985. Influence of tillage on nutrient uptake and yield of corn. Agron. J. 77:763-768.

12. Johnson, M. D., and Lowery, B. 1985. Effects of three conservation tillage practices on soil temperature and thermal properties. Soil Sci. Soc. Am. J. 49:1547-1552.

13. Kapusta, G., Krausz, R. F., Mathews, J. L. 1996. Corn yield is equal in conventional, reduced and no-till after 20 years. Agron. J. 88:812-817.

14. Ketcheson, J. W. 1968. Effect of controlled air and soil temperature and starter fertilizer on growth and nutrient composition of corn. Soil Sci. Soc. Am. Proc. 32:531-534.

15. Mackay, A. D., and Barber, S. A. 1984. Soil temperature effect on root growth and phosphorus uptake of corn. Soil Sci. Soc. Am. J. 48:818-823.

16. Mallarino, A. P., Bodoli, J. M., and Borges, R. 1999. Phosphorus and potassium placement effects on early growth and nutrient uptake on no-till corn and relationships with grain yield. Agron. J. 91:37-45.

17. Mascagni, H. J., and Boquet, D. J. 1996. Starter fertilizer and planting date effects on corn rotated with cotton. Agron. J. 88:975-982.

18. Mengel, D. B. 1992. Fertilizing corn grown using conservation tillage. Agron. Guide 268. Purdue Univ. Coop. Ext. Serv. West Lafayette, IN.

19. Randall, G. W., and Hoeft, R. G. 1988. Placement methods for improved efficiency of P and K fertilizers: A Review. J. Prod. Agric. 1:70-79.

20. Ritchie, S. W., Hanaway, J. J., and Benson, G. O. 1993. How a corn plant develops. Spec. Rep. 48. Rev. ed. Iowa State Univ. Coop. Ext.

21. Scharf, P. C. 1999. On-farm starter fertilizer response in no-till corn. J. Prod. Agric. 12:692-695.