The state of phosphorus balance on 58 Virginia dairy farms
| Autor: | Austin Pearce, Rory O. Maguire |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Farms
Environmental Engineering Nitrogen chemistry.chemical_element 010501 environmental sciences Management Monitoring Policy and Law 01 natural sciences Crop Agricultural science Animals Waste Management and Disposal Productivity Poultry litter 0105 earth and related environmental sciences Water Science and Technology Phosphorus Virginia 04 agricultural and veterinary sciences Milk production Animal Feed Pollution Manure Farm Gate Dairying Balance (accounting) chemistry 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Environmental science Cattle |
| Zdroj: | Journal of Environmental Quality. 49:324-334 |
| ISSN: | 1537-2537 0047-2425 |
| DOI: | 10.1002/jeq2.20054 |
| Popis: | Managing a sustainable dairy farm requires balancing phosphorus (P) imports and exports that enter and leave through the farm gate. Over the long term, P surpluses will elevate soil-test P concentrations above crop requirements through routine land applications of manure. The objectives of this study were aimed at Virginia dairy farms (a) to determine P mass balances, (b) to define potential guidelines for a sustainable and feasible zone of operation based on P balance and P use efficiency, and (c) to assess risk factors driving P surplus and P use inefficiencies. Data on farm-gate P imports and exports via feed, manure, crops, fertilizers, bedding, animals, and milk were collected for 58 dairy farms in Virginia. There was no relationship between farm P balance and milk production, indicating that a P surplus was not necessary for good milk productivity. A feasible P balance limit was calculated below which 75% of farms could operate, and this was 18.7 kg P ha-1 . Two risk factors were identified for farms having a P balance above this limit: (a) land application of poultry litter and (b) excessive import of P through feed. Combined dairy and beef operations generally had more land and a lower P balance, whereas having combined dairy and poultry did not raise the P balance as long as poultry litter was exported. Dairy farms in Virginia can operate with a sustainable P balance as long as they avoid using excessive poultry litter and pay attention to P imported through purchased feed. |
| Databáze: | OpenAIRE |
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