Karl Czymmek

CONVERSION OF MODIFIED MORGAN AND MEHLICH-III SOIL TESTS TO MORGAN SOIL TEST VALUES

In several states in the Northeastern U.S., the Morgan or Modified Morgan soil tests are used as the basis for both fertilizer recommendations and P runoff risk indices. However, private laboratories servicing these states typically use the Mehlich-III solution as their basic soil test extractant. To meet Natural Resources Conservation Service standards for nutrient management and to use land grant university research databases to derive recommendations, accurate conversions from Mehlich-III and Modified Morgan to Morgan are needed. A study was conducted in New York to: (i) develop models that convert Mehlich-III P, K, Ca, and Mg soil tests to Morgan equivalents; and (ii) evaluate the impact of the use of these prediction models on agronomic recommendations for corn and the New York P index. Soils from 235 locations (27 different New York soil types) were analyzed for pH, modified Morgan P, and Morgan-and Mehlich-III extractable P, K, Ca, Mg, Fe and Al. Multiple regression analysis was used to derive conversion models that fit the data. The models were validated, and the impact of their use on fertilizer recommendations was assessed using a set of >10,000 independently collected New York soil samples. Morgan and Mehlich-III extractable K, Ca, and Mg were correlated linearly with slopes approaching 1. For P, the best model fit was obtained using pH, Mehlich-III P, Ca, and Al as independent variables (r2 = 0.88). A slightly less reliable prediction was obtained without Al (r2 = 0.82). The use of Morgan equivalents did not alter the percentage of low, medium, high, and very high soils in the New York data set, nor did it affect the P index classification. Recommendations for corn derived from a database with independently collected Mehlich-III soil test data (without Al) were identical to those obtained using measured Morgan values for 57% of all samples. An additional 32% showed <10 kg P2O5 ha−1 difference. Eight percent predicted P applications that were 15–20 kg P2O5 ha−1 larger or smaller, whereas 3% showed deviations >20 P2O5 ha−1. Inclusion of Mehlich-III Al data is expected to improve the accuracy of the recommendations and assessment of the P index. We conclude that conversion equations can be used to derive accurate Morgan equivalents based on pH, Mehlich-III P, Ca, and Al, but the results need to be verified based on land use history.

Managing manure for sustainable livestock production in the Chesapeake Bay Watershed

Manure presents one of the greatest challenges to livestock (dairy and beef cattle, swine, poultry, equine, sheep, llamas, etc.) operations in the Chesapeake Bay Watershed, serving both as resource and liability. The Chesapeake Bay is threatened by excessive nutrient loadings, and, according to the US Environmental Protection Agency (USEPA), manure is the source of 18% of the nitrogen and 27% of the phosphorus entering the Chesapeake Bay annually (figure 1) (Chesapeake Bay Program 2010). Developing economical, practical, and effective manure management options for livestock producers will not only contribute to the restoration of the Chesapeake Bay, but will also provide a model for other areas where water quality and livestock production objectives must be balanced. The 166,000 km2 (64,000 mi2) Chesapeake Bay Watershed is home to 3.2 million animal units (animal unit = 454 kg [1,000 lbs] of livestock) generating roughly 36 million t (40 million tn) of livestock manure per year. In comparison, the 14 million humans who call the Chesapeake Bay Watershed home generate 3.6 million t (4 million tn) of waste annually (Brosch 2010; Blankenship 2005). The livestock manure contains approximately 259,000 t (285,000 tn) of nitrogen and 70,000 t (77,000 tn) of phosphorus. Most manure is…

Past and future phosphorus balances for agricultural cropland in New York State

New York State has a large dairy industry resulting in considerable amounts of manure being applied to cropland. Cropland phosphorus (P) balances (manure and fertilizer P minus crop P removal) combined with soil P assessments are illustrative of both challenges and opportunities for long-term sustainability of cropland management at the farm, county, and state scales. Our objectives were to (1) estimate state, regional, and county-level cropland P balances for NY in 2002, (2) evaluate P-balance trends over time (1987, 1992, 1997, and 2002), and (3) quantify the impact of improved herd nutrition and reduced fertilizer use on cropland P balances. Cropland P balances were derived from animal and cropland data from the Census of Agriculture and New York Agricultural Statistics Annual Bulletins and annual farm-use fertilizer sales data. In 2002, cropland P inputs were estimated at 12.7 and 20.9 million kg (28.1 and 46.1 million lb) of P for fertilizer and manure, respectively. Of the manure P, 69% originated from dairy cows. Crop P removal was 21.1 million kg (46.5 million lb), resulting in an overall P balance of +12.5 million kg (+27.6 million lb) or +8.0 kg P ha-1 (+7.2 lb P ac-1), a considerable improvement over 1987 when the statewide P balance was 24.4 million kg (+53.7 million lb) or 15.4 kg P ha-1 (+13.8 lb P ac-1). Without taking into account recent improvements in dairy herd nutrition (i.e., assuming a P excretion of 28 kg cow-1 [62 lb cow-1] per production period), the ratios of P in manure to P in crops were 1.10, 1.12, 1.00, and 0.99, for 1987, 1992, 1997, and 2002, respectively. Thus, the decrease in P balance from 1987 to 2002 reflected reduced fertilizer P use. When improvements in dairy nutrition were taken into account (a decrease in P excretion of dairy cows from 28 to 18 kg cow-1 [62 to 40 lb cow-1] per production period), the 2002 statewide P balance decreased from +8.0 to +4.8 kg ha-1 (+7.2 to +4.3 lb ac-1). This additional reduction illustrates the impact of precision feeding on overall cropland P balances. With a P excretion of 18 kg cow-1 (40 lb cow-1) per production period, increased yields in 2006 (reflected in crop P removal of 23,255 versus 21,104 Mg [25,639 versus 23,268 tn] in 2002) and reduced P fertilizer sales (10,508 versus 12,725 Mg [11,586 versus 14,030 tn] in 2002), the estimated P balance for 2006 amounted to +1.7 kg ha-1 (+1.5 lb ac-1). These assessments illustrate (1) the importance of precision feeding and cropland fertility management for the long-term sustainability of the dairy sector, and (2) the progress made through enhanced agricultural environmental management in New York.

Evaluation methods for a combined research and extension program used to address starter phosphorus fertilizer use for corn in New York

Ketterings, Q. M., Czymmek, K. J. and Swink, S. N. 2011. Evaluation methods for a combined research and extension program used to address starter phosphorus fertilizer use for corn in New York. Can. J. Soil Sci. 91: 467-477. Since there is no substitute for phosphorus (P), judicious use of P fertilizer is needed to protect water quality, world P reserves and farm economics. In 2001-2003, 78 on-farm corn (Zea mays L.) P trials were conducted on New York State (NY) dairy farms as part of a statewide, integrated (research and extension), outcome-focused project. The data showed fertilizer P could be eliminated or reduced to less than 28 kg P2O5 ha-1 for fields very high or high in soil test P, respectively. We conducted: (1) case study P fertilizer management evaluations using 30 NY, and (2) a producer survey using a postcard evaluation tool, to determine project outcome potential and farmer intent to change P management. The two impact evaluations showed (1) P use could be reduced to 17 kg of P2O5 ha-1 or less with soil-test based decision making, and (2) 81% of producers were likely to change P use in future years. Statewide P fertilizer sales decreased from 12 603 Mg (8.6 kg ha-1) in 2000 to 10 092 tons (6.8 kg ha-1) in 2007, a 20% reduction in P use. These results reflect the effectiveness of the impact evaluation tools and of outcome-based projects where extension and research are integrated and farmers and farm advisors are key participants in the design and implementation of the project.

Phosphorus Index as a Phosphorus Awareness Tool: Documented Phosphorus Use Reduction in New York State

In 1999, New York introduced its concentrated animal feeding operation (CAFO) permit followed, in 2001, by release of the New York phosphorus index (NY-PI) and establishment of a statewide on-farm research partnership. State policy requires that the Natural Resources Conservation Services 590 nutrient management standard, and therefore the NY-PI, be implemented on all CAFO farms as well as animal feeding operations (AFOs) receiving state or federal cost share funds for manure storage and other related practices. Since the introduction of the NY-PI, P fertilizer sales (farm use) declined from 14,470 Mg in 2001 (8.6 kg P ha) to 7,376 Mg in 2009 (5.0 kg P ha). Cost of fertilizer was not a significant covariate for the reduction in P use over time. Certified nutrient management planners were surveyed in 2011 to evaluate their perceptions of drivers for changes in P use. In addition, whole farm P balances were recorded for 54 New York dairy farms. The survey data illustrate key ingredients for success: (i) statewide awareness of environmental challenges through both regulations and extension programming; (ii) science-based, user-friendly tools that allow for farm-specific responses to the challenges; (iii) risk assessment of management alternatives through on-farm research; (iv) enforcement of regulations; and (v) existence of economically feasible alternatives. Whole farm balances showed a reduction in P surplus of 44%, averaged across farms, whereas milk production increased, further illustrating the willingness and economic potential to make changes that improve production efficiency and reduce risk of nutrient loss to the environment.

Changes in nutrient mass balances over time and related drivers for 54 New York State dairy farms

Whole-farm nutrient mass balances (NMB) can assist producers in evaluation and monitoring the nutrient status of dairy farms over time. Most of the previous studies that report NMB for dairy farms were conducted over 1 to 3 yr. In this study, annual N, P, and K mass balances were assessed on 54 dairy farms in New York State for 4 to 6 yr between 2005 and 2010 with the objectives to (1) document changes in NMB over time and drivers for change, and (2) identify nutrient use efficiency parameters that predicted the potential for improvement in NMB. The study farms varied in size (42 small, 12 medium and large) and management practices. Phosphorus, K, and 2 N balances (N1 without N2 fixation, and N2 including N2 fixation) were calculated. In general, farms with high initial NMB levels reduced them over time whereas farms with negative NMB tended to increase their NMB, demonstrating a tendency across all farms to move toward more optimal NMB levels over time. Sixty-three to 76% of farms (depending on the nutrient) reduced their NMB per hectare over the 4 to 6 yr, and 55 to 61% of these farms were able to do so while increasing milk production per cow. Across all farms, the overall reduction in NMB per hectare averaged -22kg of N/ha for N1 (29% reduction), -16kg of N/ha for N2 (15% reduction), -4kg of P/ha (36% reduction), and -10kg of K/ha (29% reduction). Change in feed imports was the most important driver for change in N and P balances across farms, whereas adjustments in both feed and fertilizer imports affected the K balances. Key predictors of potential areas for improvement in NMB over time include total nutrient imports, feed imports, animal density, percentage of farm-produced feed and nutrients, and feed nutrient use efficiency. Overall, this study highlights the opportunities of an adaptive management approach that includes NMB assessments to evaluate and monitor changes in nutrient use efficiency and cost-efficiency over time.

Nitrogen balances for New York State: Implications for manure and fertilizer management

New York (NY) has dairy, cash grain, fruit, and vegetable industries located in close proximity to water, making it important to optimize manure and fertilizer use for both economic production of crops and protection of the environment. The gross phosphorus (P) balance for NY (manure and fertilizer P minus crop P removal) estimated for 2006 was +1.7 kg ha−1 (+1.5 lb ac−1), indicating that, on a statewide basis, P is in balance. Our objectives in this study were to (1) estimate state, regional, and county-level gross nitrogen (N) balances for NY for 2007; (2) evaluate N balance trends over time (1987, 1992, 1997, 2002, and 2007); (3) estimate nonlegume cropland (net) N balances for 2007; and (4) quantify the potential impact of improved herd nutrition and manure incorporation on N balances. The 2007 NY gross N balance for nonlegume cropland was +62 kg ha−1 (+55 lb ac−1). Long Island and western NY had the highest N balances (+101 and +77 kg ha−1 [+90 and +69 lb ac−1], respectively) reflecting N fertilizer use for horticultural and/or cash grain crops (both regions) and presence of a concentrated dairy industry (western NY). The Chesapeake Bay watershed and Lake Champlain Basin counties had gross N balances below +28 kg ha−1 (+25 lb ac−1). The statewide N balance decreased from +125 kg ha−1 (+112 lb ac−1) in 1987 to +62 kg ha−1 (+55 lb ac−1) in 2007, largely driven by a decline in N fertilizer use between 1987 and 1992. The statewide N balance dropped to −38 kg ha−1 (−34 lb ac−1) when manure N losses in the barn and storage system and at land application were taken into account. Given a nearly zero P balance, a negative N balance indicates the need for best management practices that increase N use efficiency of manure and fertilizer and/or add N from other sources (cover crops, greater reliance on N fixation, shorter rotations). Improvement in herd nutrition through precision feeding has the potential to increase N use efficiency of surface applied manure and thus reduce N loss to the environment. However, such improvements will also reduce the total amount of N excreted and decrease the N:P ratio of the manure. Best management practices that reduce N loss in the barn and storage system, increase manure and fertilizer N uptake efficiency, and/or reduce N needs will be essential in order to balance N and P for the long-term sustainability of NY agriculture.

Nutrient management planners' feedback on New York and Pennsylvania phosphorus indices

State phosphorus indices (PIs) are being evaluated across the United States due to variability in phosphorus (P) management recommendations and questions about the lack of water quality improvement in some watersheds. Nutrient management planners in New York (NY) and Pennsylvania (PA) were surveyed via two separate “but related” questionnaires to document perspectives on the current NY-PI and PA-PI and to obtain recommendations for improvements. Many planners were content with the current versions of the PIs but felt improvements could be made to more strongly discourage application of manure under conditions of high P loss potential and better promote certain best management practices. The NY planners felt that the NY-PI should discourage manure application during winter and to fields near streams, and should more strongly promote manure incorporation or injection, establishment of cover crops, ground coverage with crop residues, and implementation of setbacks and vegetated buffers. Similarly, the PA planners felt that the PA-PI should more strongly discourage manure application to fields with insufficient ground cover, near subsurface drainage and surface inlets, and during winter. In addition, the PA planners said the PA-PI should more strongly encourage soil conservation practices such as no-till, use of cover crops, and vegetated buffers. Results of the survey suggest common experiences and viewpoints among planners in NY and PA, resulting in a valuable on-the-ground assessment of the PIs as a nutrient management planning tool in both states, and the potential for development of a single, physiographic region PI.

Upper Susquehanna watershed and New York State improvements in nitrogen and phosphorus mass balances of dairy farms

States in the Chesapeake Bay watershed (CBW) are required to reduce nitrogen (N) and phosphorus (P) loads from agriculture to achieve water quality goals for 2025. Assessing nutrient mass balances (NMBs) on farms over multiple years allows for evaluation of trends in nutrient accumulation and potential losses in geographic regions. Between 2004 and 2013, 570 NMBs were conducted for 189 dairy farms in New York, including 91 farms (293 NMBs) in the Upper Susquehanna watershed (USW), headwaters of the CBW. The average NMBs per hectare and per megagram of milk were lower for farms in the USW than statewide. Data showed a decline in NMBs per hectare over 10 years that ranged from 29% to 42% (statewide) and from 29% to 51% (for the USW dairies), depending on the nutrient, while milk production remained constant in both regions. Reductions in NMBs resulted primarily from reductions in nutrient imports, particularly through feed management. These source reductions reflect increased efficiency of production and reduced risk of N and P loss to the CBW. Extrapolation of comparisons in NMBs between 2004 and 2013 suggest that dairies in the USW reduced total N and P imports by 30% and 20%, respectively, contributing to a 29% to 50% decrease in total N pool and 51% decrease in P pool. We conclude that USW dairy farms can deliver up to 49% of their 2013 N pool and up to 72% of their 2013 P pool at the edge of the farms (their NMB) and still meet the total maximum daily load (TMDL) for N and P set for 2025 for New York agriculture. This study illustrates that significant nutrient source reduction can be obtained by implementing nutrient conservation practices, such as precision feeding and fertilizer management, combined with annual assessment of whole farm balances. Such a reduction in nutrient imports onto farms results in a reduction of the pool of nutrients available for accumulation in the soil or direct loss to water bodies and the atmosphere.

Long-term trends of nitrogen and phosphorus mass balances on New York State dairy farms

The whole-farm nutrient mass balance (NMB) is an adaptive management tool that can be used to identify areas for improvement in nutrient management and to monitor progress over time. The objectives of this study were to (1) evaluate the trends of nitrogen and phosphorus mass balances of 27 New York State dairy farms over 6 to 10 yr, (2) identify specific management changes made by 4 case study farms that improved NMB over time by shifting NMB up or down depending on the initial NMB, and (3) evaluate the potential of key indicators to identify opportunities for improvement in NMB. During the study period, milk price fluctuated whereas costs associated with feed and fertilizer increased substantially. Of the 27 farms, 67 to 74% (depending on the nutrient) decreased NMB per hectare over time, whereas 63 to 67% decreased NMB per megagram of milk over time. In general, changes in NMB were directionally correct, with 43 to 56% of farms operating in the optimum operational zone (with both NMB per hectare and per megagram of milk below the feasible levels suggested for New York) toward the end of the study versus 22 to 26% in the first 2 yr of the assessments. The 4 case study farms improved their NMB, whole-farm nutrient use efficiencies, and feed nutrient use efficiencies while maintaining or increasing milk production per cow. The case study farmers made the largest changes in precision feed management, reducing protein and P in purchased feed by replacing concentrates with blends with lower nutrient concentrations. Total nutrient imports, feed imports, the percentage of homegrown feed and nutrients, the concentration of nutrients in the purchased feed, fertilizer imports, and overall crop yields were useful in identifying potential areas for improvement in NMB.