Livestock production, and particularly manure management, has received environmental scrutiny for years due to potential nitrate contamination in ground and surface waters. During the 1990s, many land grant institutions developed and conducted research and extension programs related to the management and crediting of manure N. To assess the current status of manure N crediting and management in the USA, a national survey of university faculty considered to have expertise in manure issues was conducted. A four-page mail survey was sent to one person in each state to provide qualitative and quantitative information regarding manure N management. A response rate of 86% was achieved. Groundwater and surface water quality are perceived as the top environmental ramifications of manure N management regardless of animal species. Manure N crediting for cropland is highest for poultry operations and lowest for beef operations. Approximately 45% of poultry manure is properly credited, compared with only 18% of beef manure. In addition, manure N crediting is overwhelmingly viewed as improved compared with 5 yr ago. Manure N crediting components being emphasized include manure testing, soil N testing, and spreader calibration. Management strategies being implemented include writing manure management plans, reduced application rates, and manure injection/incorporation. Regulation—either existing, proposed, or future—is perceived as the primary reason (61%) for producers to better manage their manure. More states will regulate their livestock enterprises via a permitting process in the future, and the trend in developing nutrient plans is toward using a combination N and P standard, rather than solely an N standard. Although N issues have been a focus of manure management in the past, P issues have escalated in the 1990s in terms of environmental importance. The Issue Livestock production, and particularly manure management, has received environmental scrutiny for years due potential nitrate contamination in ground and surface waters. Environmental issues related to manure management have led to numerous federal, state, and local government programs. During the 1990s, most land grant institutions developed and conducted research and extension programs related to N crediting and management of manure. We hypothesized that, although manure management programs were focused initially on N, the current emphasis may be switching to P. Thus, one could ask “Is the manure N issue lessened in its importance?” or “Has the manure N perception changed?” Study Description To assess the current status of manure N crediting and management in the USA, the authors sent a four-page mail survey to one university faculty member per state whose research/extension programs focused on or included manure management. A response rate of 86% was achieved. Applied Questions How well are livestock producers crediting land applications of manure N? University experts report low levels of manure N crediting (Fig. 1). On a scale of 1 (poor) to 7 (excellent), overall crediting of manure N by producers ranges from 2.4 for beef to 4.1 for poultry. Dairy and swine producers are in between, with scores of 3.5 and 3.2, respectively. The percentage of manure N being properly credited ranges from 18% (beef) to 45% (poultry). What strategies are being implemented regarding improved manure N management? Figure 1Open in figure viewerPowerPoint Perceived estimates of manure N crediting. Overall manure N crediting for each species was based on a scale from 1 (none) to 7 (excellent). Proper crediting was asked in terms of percentage of manure N being applied to fields that received the appropriate credit (0-100%). Manure testing is the most frequent component of manure N crediting being emphasized. Closely following manure testing is soil testing for N. A distant third is manure spreader calibration. Several other components were also mentioned by respondents but were considered to receive only minor emphasis. The most common manure management strategy being implemented is “writing manure management plans.” “Reduced application rates” is the next strategy in popularity, followed by “incorporation/injection.” However, a geographic relationship existed for the listed strategies. The diversity in these strategies among regions reflects the broad nature of the problem with manure crediting and the difficulty in implementing recommendations. What is the role of regulation in manure N management? Regulation is the most frequent response to why producers are implementing new manure management strategies on their farms. Current and pending regulations and the threat of new regulations combine for 61% of the responses. Educational efforts, economics (fertilizer replacement value), and peer pressure were also reasons listed by some respondents. States have varying concern about regulation, depending on their current manure regulations. Regulation will continue to be a major factor in changing manure management, although it will not necessarily always improve manure N management.
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Jan 22, 2022
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