Progress 10/01/01 to 09/30/06
Outputs
Crop rotations and their effect on soil/plant nitrogen relationships are one of the primary methods that gardeners and commercial growers have to manage their nitrogen fertility requirements in both organic and traditional vegetable production. The results of this project showed that the rotational cropping sequence can markedly affect how much nitrogen fertilizer is required to successfully produce vegetable crops. In the rotation sequence, crops such as corn, which leave a high carbon residue in the soil (i.e. corn stubble) will increase nitrogen fertilizer requirements significantly (by as much as 30%) for next year's vegetable crop. In contrast, high nitrogen-residue crops such as soybean and vetch will decrease next year's nitrogen fertilizer requirement (by as much as 25-44%). Including two consecutive (i.e. back-to-back) years of corn in the rotation can increase nitrogen fertilizer requirements by up to 70%, with some of this added nitrogen fertilizer subject
to leaching. The results also showed that differences in cropping system rotations for their effects on nitrogen fertilization rates are likely to be more pronounced on lighter, less N-fertile soils with orgaqnic matter content less than 2.0% than on heavier darker soils with organic matter contents greater than 3.5%.
Impacts
This information will help both traditional and organic vegetable growers manage their nitrogen fertility requirements to achieve maximum yields and concomittantly limit adverse environmental effects of nitrate pollution and runoff from agricultural sources.
Publications
- No publications reported this period
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Progress 01/01/05 to 12/31/05
Outputs
This work showed that nitrogen fertilizer requirements for pumpkins on loam soil will vary markedly depending on the year-to-year cropping sequence, with the amount of N fertilizer needed for highest pumpkin yields increasing when the previous year's crop was corn, and decreasing when the previous year's crop was soybeans. Optimum N fertilizer requirements for pumpkin production on loam soil were estimated at 97 pounds N fertilizer per acre when the previous year's crop was soybean, 135 pounds N fertilizer per acre when the previous year's crop was corn, and 159 pounds N fertilizer per acre when pumpkins follow 2 consecutive years of corn. Additionally adverse effects on pumpkin production from excessive amounts of N fertilizer were greater in pumpkins following soybeans than in pumpkins following corn. Preplant soil tests for nitrate-N showed that pumpkins are likely to show significant response to added N fertilizer when the level of nitrate-N in the soil measured
in the spring before planting was less than 17.6 parts per million, and relatively smaller response when preplant soil nitrate-N is greater than 17.6 parts per million. Current University of Illinois fertilizer guidelines for pumpkins recommend 120 pounds of N fertilizer per acre, plus a N credit (reduction) of 25 pounds N fertilizer per acre following soybeans or other legumes. Based on these results, the above recommendations appear reasonably accurate for pumpkin crops following soybeans, but underrated following corn. Including two consective years of corn in the rotation with pumpkins is likely to require high rates of N fertilizer (159 pounds N per acre), with some of this N subject to possible leaching losses.
Impacts
Nitrogen is a critically important nutrient in pumpkin production, both from a plant and an environmental perspective. While too little N can cause reduced fruit size and low yields, excess N can result in N runoff in surface water. The information obtained from this research will increase N-fertilizer efficiency for pumpkin production on fine-textured soil.
Publications
- Swiader, J.M. and Shoemaker, W.H. 2004. Rotational cropping sequence affects nitrogen fertilizer requirements in pumpkin (Cucurbita moschata Poir.). HortScience. 39:71-75.
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Progress 01/01/04 to 12/31/04
Outputs
In Illinois, pumpkins are traditionally grown in rotation with corn and soybeans, with pumpkins sometimes following corn or 2-yrs corn, and other times following soybeans. Based on research with other crops, fertilizer N requirements are likely to vary depending on cropping sequence. Soybean N-credits specific for pumpkins have not been reported. The objective of this study was to determine optimal fertilizer N requirements in pumpkin, taking into account previous crops of corn and soybeans, and any rotational N-credits. These results demonstrate that fertilizer N requirements for pumpkins on loam soil will increase following corn or 2-years corn in the rotation, and decrease following soybeans. The results of this research may be extendable to other pumpkin and winter squash types with similar N requirements.
Impacts
The overall goal of this project is to develop and establish reliable and accurate recommendations and guidelines for nitrogen (N) fertilization practices in organically- and traditionally-grown vegetables. The results of this research will enhance the production, as well as quality, of vegetable food crops and increase production efficiency through manipulation of plant mineral nutrition and application of environmentally sound fertilizer management practices. In context of these mutual environmental and production consequences of mismanaged N fertilization, N fertilizer-use efficiency has become a major goal of Illinois pumpkin production.
Publications
- Swiader, J.M. and Shoemaker, W.H. 2004. Rotational cropping sequence affects nitrogen fertilizer requirements in processing pumpkins (Cucurbita moschata). HortSci. 39:71-75.
- Mulvaney, R.L., Yaremych, S.A., Khan, S.A., Swiader, J.M. and Horgan, B.P. 2004. Use of diffusion to determine soil cation-exchange capacity by ammonium saturation. Commun. Soil Sci. Plant Anal. 35:51-67.
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Progress 01/01/03 to 12/31/03
Outputs
Research was conducted to evaluate a dryblend by-product (SA) from food/beverage processing that contains fermentation derivatives, including yeast (dead) and some sugars, as an organic soil amendment in vegetable crop production. Based on past reports for potatoes (undocumented) and mushrooms (undocumented) there is reason to believe that SA might have positive effects on plant growth. The exact reason for this effect is not clear; it may stimulate growth of favorable soil bacteria that in some way may be beneficial to plants (i.e. C:N ratio), although there is no data to support this supposition. With a chemical content of 3.4% nitrogen (N), 0.7% phosphorus (P), and 1.0% potassium (K), there may also be some nutritive effect, especially with nitrogen on less fertile soils. In this present study, SA at 2 or 10 tons per acre had a positive effect on tomato fruit yield. Compared to the control (0 SA), total fruit yields increased 22% and 58% with 2 and 10SA,
respectively. Tomato fruit count followed a similar pattern. Daily visual field observation clearly showed enhanced plant growth throughout the season from SA application. Based on the results, it appeared that some of the positive effect of SA on tomato yield was due to enhanced nitrogen (N) nutrition. However, this N effect could not account for all of the large increase in tomato yield with 10SA, suggesting that other factors, in addition to improved N nutrition, were responsible for the excellent yield response with SA. Subsequently, end-of-season soil test results showed no effect of SA on soil total N or exchangeable K content. However, there was a small numerical (although statistically non-significant) increase in soil organic matter with application of 10SA. This could be of practical significance (as well as help explain some of the positive yield response to SA in this study), since small changes in soil organic matter content are generally magnified disproportionately in
terms of impact on soil properties and plant growth. Regardless of the reason, however, based on the potential benefits and the favorabl effect of SA on tomato response in this study (as well as reports in other crops), we believe that further in-depth study evaluating SA as a soil additive is warranted.
Impacts
The overall goal of this project is to develop and establish reliable and accurate recommendations and guidelines for nitrogen (N) fertilization practices in organically- and traditionally-grown vegetables. The results of this research will enhance the production, as well as quality, of organically-grown vegetable food crops and increase production efficiency through manipulation of plant mineral nutrition and application of environmentally sound fertilizer management practices. As shown by these results, using an alternative N fertilizer source generated as a waste-product from food/beverage processing, inorganic N fertilizer rates for optimum tomato production may be reduced by over 50%.
Publications
- David, M., Swiader, J.M., Williams, K. and Eastburn, D. 2003. Nitrogen nutrition, but not potassium, affects powdery mildew development in Hiemalis begonias. J. Plant Nutr. 26:159-176.
- Swiader, J.M. and Moore, A. 2002. SPAD chlorophyll and plant N relationships in dryland and irrigated pumpkins. J. Plant Nutr. 25:1089-1100.
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Progress 01/01/02 to 12/31/02
Outputs
In this present study, research was conducted to determine the effect of previous cropping systems on N fertilizer requirements in pumpkin cultivar 'Libby-Select'. The results showed that the previous cropping system will have marked effect on optimal N fertilization rates, with N requirements increasing following corn or 2-years corn, and remaining relatively unchanged following soybeans. Despite similar total yield levels of approximately 38 tons per acre, the optimal N rate for maximum yield of ripe pumpkin fruit following soybeans was estimated at 107 lbs N/acre, compared to 119 lbs N/acre following fallow ground, suggesting a N credit of 12 lbs/acre for the soybean cropping system. In contrast, the optimal N rate for maximal fruit yield following corn or 2-years corn was estimated at 130 lbs N/acre following corn and 188 lbs N/acre following 2-years corn, resulting in a N debit of 11 and 69 lbs N/acre, respectively. Preplant soil tests (0-18 inches) taken prior
to planting the pumpkins showed that initial amounts of soil organic matter and total soil N were unaffected by cropping system. In contrast, preplant soil nitrate (NO3-N) measurements tended to reflect the previous cropping system, with soil NO3-N levels highest following fallow ground and lowest following 2-years corn. Averaged over the four cropping systems, relationships between preplant soil NO3-N levels and the percentage response of ripe yield showed a positive response (R2=0.38) to N fertilization at soil NO3-N levels < 18.0 mg N/kg. Based on these data, it appears that the some estimate of soil NO3-N carryover can be made in each cropping system to adjust fertilizer N fertilizer recommendations for succeeding pumpkin crops.
Impacts
The overall goal of this project is to develop and establish reliable and accurate recommendations and guidelines for nitrogen (N) fertilization practices in organically-grown vegetables. Special focus will be given to N management practices that concomitantly maximize growth and quality relationships in organically-grown vegetable crops, yet are environmentally and economically sustainable.
Publications
- Swiader, J.M. and Moore, A. 2002. SPAD-chlorophyll response to nitrogen fertilization and evaluation of nitrogen status in dryland and irrigated pumpkins. J.Plant Nutrition 25:1089-1100.
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Progress 10/01/01 to 12/31/01
Outputs
This project began in late 2001 and as of yet we have no results to report.
Impacts
The overall goal of this project is develop and establish reliable and accurate recommendations and guidelines for N fertilization practices in organically-grown vegetables. Special focus will be given to N management practices that concomitantly maximize growth and quality relationships in organically-grown vegetable crops, yet are environmentally and economically sustainable.
Publications
- No publications reported this period
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