Progress 10/01/00 to 09/30/06
Outputs
Research was conducted in East-central Kansas during 1983-2005 to measure the effects of long-term continuous harvesting of crop residues on soil properties and crop yields in a soybean, wheat, grain sorghum/corn rotation, fertilized with different levels of N, P, and K. The harvesting of crop residues had little impact on crop yields. Only one year was there a statistically significant yield reduction because of crop residue harvesting. Grain yields when averaged across all fertilizer treatments and years, and when normalized for crops, produced grain yield ratios of 1.00 with normal residues incorporated, 0.99 with annual residue harvesting, and 0.98 with 2X normal residues incorporated. The fertilizer treatments, zero, low, normal and high levels of N, P, and K produced highly significant yield differences and had normalized yield ratios of 0.83, 0.94, 1.06 and 1.13, respectively. Soil organic matter and soil exchangeable K were most affected by crop residue
harvesting. Soil organic matter decreased 13 percent and soil exchangeable K decreased 15 percent during the course of this study.
Impacts
Harvesting of crop residues for things such as furniture board, livestock feed, and bio-fuels appears to be not that detrimental over the moderate term in the western corn-belt if from fields having initially good soil organic matter levels, fertility, water availability, and limited soil wind and water erosion. Especially, if nutrients removed by the crop residues are replenished. However, the very long-term continuous harvesting of crop residues remains questionable as a sustainable practice. This is because very long-term harvesting of crop residues could lower soil organic matter levels to critical low levels where yields might be affected. It is difficult to know exactly at what level that might be as soil organic matter impacts numerous factors such as soil aggregation, soil water infiltration and water holding capacity, bulk density, aeration, nutrient cycling, ion exchange capacity and buffering all of which could individually or in combination affect crop
production. To prevent soil organic matter levels from dropping to critical levels will likely require that the harvesting of crop residues be less than 100% annually or only from certain crops in the rotation certain years. Use of conservation tillage practices such as no-till or the growing of cover crops during the off-season might also be necessary to prevent the decline in soil organic matter.
Publications
- No publications reported this period
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Progress 01/01/05 to 12/31/05
Outputs
Research was conducted during 2005 to measure the effects of long-term repeated harvesting of crop residues on crop yield and soil properties in a soybean, wheat, grain sorghum/corn rotation, fertilized with different levels of N, P, and K fertilizer. The harvesting of crop residues for the 25th consecutive year caused no statistically significant reduction in yield. Soybean yields, when averaged across all fertilizer treatments, were 3158 kg/ha with annual residue harvesting, 3271 kg/ha with normal residue incorporated, and 3237 kg/ha with 2X normal residue incorporated. The fertilizer treatments (zero, low, normal and high levels of N, P, and K) also produced no significant yield differences in 2005. Soybean yields ranged from 3158 kg/ha at the zero rate of fertilizer to 3261 kg/ha at the highest level of fertilizer. Soil organic matter and soil exchangeable K declined with repeated crop residue harvesting.
Impacts
Repeated harvesting of some crop residues in the western cornbelt for such uses as furniture board, paper, and ethanol appears to be an option and not that detrimental over the moderate term from fields having initially good soil organic matter, fertility and limited soil erosion potential. Especially if nutrients removed by the crop residues are replenished. However, the really long-term harvesting of crop residues remains questionable as a sustainable practice. This is because very long-term harvesting of crop residues could eventually lower soil organic matter to a level in which yield is affected. It could take centuries for that to occur, however, as organic matter in prairie soils were developed over thousands and thousands of years.
Publications
- No publications reported this period
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Progress 01/01/04 to 12/31/04
Outputs
Research was conducted during 2004 to measure the effects of long-term repeated harvesting of crop residues on crop yield and soil properties in a soybean, wheat, grain sorghum/corn rotation, fertilized with different levels of N, P, and K fertilizer. The harvesting of crop residue for the 24th consecutive year caused no statistically significant differences in grain yield. Corn yields, when averaged across all fertilizer treatments, were 7207 kg/ha with annual residue harvesting, 6834 kg/ha with normal residue incorporated, and 6885 kg/ha with 2X normal residue incorporated. The fertilizer treatments (zero, low, normal and high levels of N, P, and K) produced highly significant yield differences. Corn yields, when averaged across all residue treatments, ranged from 5462 kg/ha at the zero rate of fertilizer to 8654 kg/ha at the highest level of fertilizer. There was no statistically significant interaction on corn yield between the residue and fertilizer treatments.
Soil test results show that soil organic matter and soil exchangeable K are declining with repeated crop residue harvesting.
Impacts
The repeated annual harvesting of crop residues appears to be not that detrimental for crop production at least when starting with initially good soil organic matter, fertility, and no water and soil erosion problems. However, the very long-term harvesting of crop residues remains questionable as a sustainable practice. This is because the very long-term harvesting of crop residues could further deplete soil organic matter which could eventually affect yield.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
Research was conducted during 2003 to measure the effects of long-term harvesting of crop residues on crop yield and soil properties in a soybean, wheat, grain sorghum/corn rotation, fertilized with different levels of N, P, and K fertilizer. The harvesting of crop residue for the 23rd consecutive year caused no statistically significant differences in soybean grain yield. Soybean yields, when averaged across all fertilizer treatments, were 1743 kg/ha with annual residue harvesting, 1785 kg/ha with normal residue incorporated, and 1829 kg/ha with 2X normal residue incorporated. The fertilizer treatments (zero, low, normal and high levels of N, P, and K) produced highly significant yield differences. Soybean yields ranged from 1576 kg/ha at the zero rate of fertilizer to 2023 kg/ha at the highest level of fertilizer. Soil test results show that soil organic matter and soil exchangeable K are declining with repeated crop residue harvesting.
Impacts
The short to moderate term harvesting of crop residues from fields having initially good soil organic matter, fertility and no problems with water and soil erosion appears to be not that detrimental for crop production. However, the very long-term harvesting of crop residues remains questionable as a sustainable practice. This is because the very long-term harvesting of crop residues could further deplete soil organic matter which could eventually affect yield.
Publications
- Janssen, K.A. and D.A. Whitney 2003. Effects of long-term crop residue harvesting on soil properties and crop yield. In D. Fjell (ed) Agronomy Field Research 2003, Kansas Agric. Exp. Sta. and Coop. Ext. Ser. Rep. of Progress SRP913, August 2003.
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Progress 01/01/02 to 12/31/02
Outputs
Research was conducted during 2002 to measure the effects of long-term harvesting of crop residues on crop yield and soil properties in a soybean, wheat, grain sorghum/corn rotation, fertilized with different levels of N, P, and K fertilizer. The harvesting of crop residue for the 22nd consecutive year caused no differences in grain sorghum yield. Grain sorghum yields, when averaged across all fertilizer treatments, were 3238 kg/ha with annual residue harvesting, 3283 with normal residue incorporated, and 3204 kg/ha with 2X normal residue incorporated. The fertilizer treatments (zero, low, normal and high levels of N, P, and K) produced highly significant yield differences. Grain sorghum yields ranged from 2631kg/ha at the zero rate of fertilizer to 3854 kg/ha at the highest level of fertilizer. Soil test results show that soil organic matter and soil exchangeable K are declining with repeated crop residue harvesting
Impacts
The harvesting of crop residues from non highly erodible fields having initially good soil organic matter and fertility appear to be not that detrimental for crop production over the short to moderate term. However, the repeated harvesting of crop residues for very long-term remains questionable as a sustainable practice. This is because very long-term harvesting of crop residues could further deplete soil organic matter which could eventually affect yield.
Publications
- Janssen, K.A. and D.A. Whitney 2002. Effects of long-term crop residue harvesting on soil properties and crop yield. In D. Fjell (ed) Field Resarch 2002. Kansas Agric. Exp. Sta. and Coop. Ext. Ser. Rep. of Progress 893, May 2002.
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Progress 01/01/01 to 12/31/01
Outputs
Research was conducted during 2001 to measure the effects of 21 years repeated harvesting and return of varying levels of crop residues on crop yield and soil properties in a soybean, wheat, grain sorghum/corn crop rotation, fertilized with different levels of N, P, and K fertilizer. The residue treatments caused no statisticaly significant differences (0.05 level) in soybean grain yield in 2001. Soybean grain yields, averaged across all fertilizer treatments, were 2,305 kg/ha with annual residue harvesting, 2395 kg/ha with normal residue incorporated, and 2337 kg/ha with 2X normal residue incorporated. The fertilizer treatments (zero, low, normal, and high levels of N, P, and K) also produced no significant yield differences. Soybean grain yields ranged flrom 2,303 kg/ha at the zero fertilizer rate to 2,338 kg/ha at the highest level of fertilizer. Soil test results show that soil organic matter and soil exchangeable K are declining with repeated crop residue
harvesting.
Impacts
The harvesting of crop residues from fields having initially adequate soil organic matter and fertility appear to be not that detrimental to crop production over the moderatre term. However, the harvesting of crop residues very long-term remains questionable as a sustainable practice. This is because very long-term harvesting of crop residues could further decrease soil organic matter and affect yield. The effects of very long-term crop residue harvesting needs further study.
Publications
- Janssen, K.A. and D.A. Whitney 2001. Effects of long-term crop residue harvesting and fertilizer application on soil properties and crop yield. In D. Fjell (ed) Field Research 2001. Kansas Agric. Exp. Sta. and Coop. Ext. Ser. Rep. of Progress 876, May 2001.
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Progress 01/01/00 to 12/31/00
Outputs
Research was conducted during 2000 to measure the effects of 20 years harvesting and return of varying levels of crop residues on crop yield and soil properties in a soybean-wheat-grain sorghum/corn rotation, fertilized with different levels of N, P, and K fertilizer. The residue treatments caused no statistically significant differences (0.05 level) in corn grain yields in 2000. Corn grain yields, averaged across all fertilizer treatments, were 5140 kg/ha with annual residue harvesting, 5063 kg/ha with normal residue incorporated, and 4990 kg/ha with 2X normal residue incorporated. The fertilizer treatments (zero, low, normal and high levels of (N, P, and K) produced significant yield differences. Corn grain yields ranged from 3084 kg/ha at the zero fertilizer rate to 6637 kg/ha at the highest level of fertilizer. Soil test results show that soil organic matter and soil exchangeable K are declining with crop residue harvesting.
Impacts
The harvesting of crop residues from fields having initially good soil organic matter and fertility appears to be not that detrimental to crop production over the short-term. However, the harvesting of crop residues long-term remains questionable as a sustainable practice. This is because very long-term harvesting of crop residues could significantly decrease soil organic matter. The effects of these long-term, slowly occurring changes in soil properties on crop yields needs further study.
Publications
- Janssen, K.A. and D.A. Whitney 2000. Crop residue removal and fertilizer effects on crop yield and soil sustainability. In D. Fjell (ed.) Field Research 2000., Kansas Agric. Exp. Sta. and Coop. Ext. Ser. Rep. of Progress 854, May 2000.
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