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United States Department of Agriculture

Agricultural Research Service

Research Project: DEVELOPMENT OF MODELS AND CONSERVATION PRACTICES FOR WATER QUALITY MANAGEMENT AND RESOURCE ASSESSMENTS

Location: Grassland, Soil and Water Research Laboratory

Title: Effects of annual turkey litter application on surface soil quality of a Texas Blackland vertisol

Authors
item Harmel, Daren
item Haney, Richard
item Smith, Douglas

Submitted to: Soil Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 9, 2011
Publication Date: May 1, 2011
Citation: Harmel, R.D., Haney, R.L., Smith, D.R. 2011. Effects of annual turkey litter application on surface soil quality of a Texas Blackland vertisol. Soil Science. 176(5):227-236.

Interpretive Summary: Proper management is essential to minimize adverse environment effects and to maximum agronomic benefits of land applying poultry litter as a nutrient source and soil amendment. In this study on clay soils of the Texas Blackland Prairie, turkey litter was applied to six cultivated and four pasture fields at rates of 0-13.4 Mg/ha (target rates as used in real-world agronomic settings). Litter application did produce increasing trends in soil organic C on the cultivated fields, but annual variability in soil test results prevented significant differences in average values between field with differing litter rates. At the end of the study following seven annual applications, litter rate was significantly related to total N, total P, extractable P, Zn, and Cu in the cultivated fields and to total P, extractable P, Zn, and Cu in the pasture fields. On cultivated fields, no significant differences in mean values occurred between the inorganic fertilizer control and the 4.5 Mg/ha litter rate, although extractable P, Zn, and Cu levels appeared to increase relative to the control at this litter rate. These observations coupled with previous findings indicate that annual litter application rates should not exceed 2.2-4.5 Mg/ha for cropland and 4.5-6.7 Mg/ha for pasture to limit buildup of extractable P, Zn, and Cu in the soil. Although these target rates appear to be appropriate, the annual variability in litter moisture and nutrient content can, if not accounted for, make it difficult to determine proper application rates in sensitive agronomic settings. In these settings, pre-application litter testing is necessary to ensure the proper litter rate, and thus the proper nutrient rate (specifically P), is applied so that crop nutrient requirements are met and environmental concerns are limited.

Technical Abstract: Proper management is essential to minimize adverse environment effects and to maximum agronomic benefits of land applying poultry litter as a nutrient source and soil amendment. In this study in the Vertisol-dominated Texas Blackland Prairie, turkey litter was applied to six cultivated and four pasture fields at rates of 0-13.4 Mg/ha (target rates as used in real-world agronomic settings). Litter application did produce significant increasing trends in soil organic C on the cultivated fields, but annual variability in soil test results precluded significant differences among treatment means. At the end of the study following seven annual applications, litter rate was significantly related to total N, total P, extractable P, Zn, and Cu in the cultivated fields and to total P, extractable P, Zn, and Cu in the pasture fields. On cultivated fields, no significant differences in mean values occurred between the inorganic fertilizer control and the 4.5 Mg/ha litter rate, although extractable P, Zn, and Cu levels appeared to increase relative to the control at this litter rate. These observations coupled with previous findings indicate that annual litter application rates should not exceed 2.2-4.5 Mg/ha for cropland and 4.5-6.7 Mg/ha for pasture to limit buildup of extractable P, Zn, and Cu in the soil. Although these target rates appear to be appropriate, the annual variability in litter moisture and nutrient content can, if not accounted for, make it difficult to determine proper application rates in sensitive agronomic settings. In these settings, pre-application litter testing is necessary to ensure the proper litter rate, and thus the proper nutrient rate (specifically P), is applied so that crop nutrient requirements are met and environmental concerns are limited.

Last Modified: 8/29/2014
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