A review of two mandatory and two voluntary nutrient management strategies is …

• Abstract
• Introduction
• Methods and assumptions
• Results and Discussion
• Conclusions
• References
• Figures
• Tables

Biology Articles » Agriculture » Evaluating Livestock System Environmental Performance with Whole-Farm Nutrient Balance » Tables

Tables

- Evaluating Livestock System Environmental Performance with Whole-Farm Nutrient Balance

..................................................

Table 1. The nutrient management plan (NMP) must address the following nine elements to comply with the National Pollutant Discharge Elimination System (NPDES) permit requirements of the concentrated animal feeding operation (CAFO) regulations (USEPA, 2003).

..................................................

Table 2. Summary of characteristics for the beef cattle feedlot used in case-study problem.

Characteristic Value Feedlot performance indicators Location      Pierce, NE       Head      2500       Average turns per year      2       Average daily gain, kg d–1      1.8       Feed/gain, kg feed kg–1 gain      6.5       Weight gain of cattle, kg      295–590       Ration information   Feed Feeding program Feeding program, Option 1   CP P Fed Purchased Fed Purchased   % of dry matter   Mg yr–1   Mg yr–1       kg animal–1 d–1     kg animal–1 d–1     Feed intake     11.8     11.8     CP, % of dry matter       13.6%     13.0%   P, % of dry matter       0.51%     0.27%   Corn  9.8 0.31  6.6 5430 4630  9.0 7410 6600 Molasses  8.5 0.03        0.6 220  220 Alfalfa 19.0 0.24  0.8 660  130  1.6 1320  780 Supplement 50.0 0        0.6 470  470 Supplement, no urea 0 0  0.6 470  470       Corn gluten feed 21 1.00  3.8 3150 3150       Soil test results and fertilizer use   Field 1: Pivot Field 2: Feedlot quarter Field 3: Dry quarter Crop grown and land area pivot: 49 ha continuous corn; corners:   12 ha alfalfa 37 ha of alfalfa 52 ha in corn–soybean rotation Five-year yield average, kg ha–1 10700 and 6700 11200 6300 (corn), 2800 (soybean) University of Nebraska N   recommendations pivot: 170 kg N ha–1; corners: – – 45 kg ha–1 for corn University of Nebraska P2O5   recommendations pivot: 45 kg ha–1 broadcast or 22 kg ha–1   as starter; corners: 34 kg ha–1   broadcast 0 kg ha–1 broadcast – Fertilizer application history pivot: 170 kg of anhydrous ammonia   and 90 kg of MAP¶ ha–1; corners:   67 kg of MAP ha–1 none 67 kg of anhydrous ammonia ha–1 Manure Harvest Manure is harvested typically after each turn of cattle and stockpiled until land-applied. Application of manure solids It is typically surface-applied on alfalfa (feedlot quarter) in summer after second cutting and on row crops in February   and not incorporated. Application of open lot runoff Open lot runoff water is collected for a 12-ha drainage area and land-applied through a big traveling gun, typically just   before spring green up on alfalfa and after the third cutting in August.

The farm participated in a survey of 33 farms from which data was collected for the purpose of estimating a whole-farm nutrient balance for each farm (Koelsch and Lesoing, 1999). To protect the identity of the farm, the case-study farm used in this discussion is shown on a site (Fig. 2) different from the farm's actual site but with a comparable land base and production potential.

Feeding program represents actual farm feeding program at the time of the survey and Option 1 represents a standard feeding program option without the corn gluten feed designed to provide similar energy and protein levels. Purchased feeds are for year in which corn is grown on dry quarter. Values are on a dry-matter basis.

Irrigation nitrate credit is not included.

^¶ Monoammonium phosphate (11–52–0).

..................................................

Table 3. Effect of alternative best management practices (BMPs) on whole-farm phosphorus balance for beef case-study farm.

Characteristic Balance 1: initial farm balance, no BMPs Balance 2: nutrient management plan (NMP) implemented on land managed by feedlot Balance 3: NMP + setbacks from water implemented Balance 4: 50% of manure transferred to off-farm users + previous BMPs Balance 5: feeding program Option 1 + NMP and setbacks (no corn gluten feed used)¶ Inputs Animals, kg P yr–1 10800 10800 10800 10800 10800 Feed, kg P yr–1 46300 46300 46300 46300 24500 Fertilizer, kg P yr–1 2400 0 400 400 400 Managed outputs Animals, kg P yr–1 19200 19200 19200 19200 19200 Crops, kg P yr–1 0 0 0 0 0 Manure, kg P yr–1 0 0 0 18100 0 Imbalance (or surplus) P, kg P yr–1 40400 37900 38300 20200 16500 P, kg P ha–1 yr–1 270 250 260 130 110 Ratio of inputs to outputs 3.1:1 3.0:1 3.0:1 1.5:1 1.9:1

Original farm balance is based on the farm characteristics described in Table 2 and Fig. 2.

These options assume the base feeding program (see Table 2) and modifications to crop nutrient management program to apply manure on an N basis (Balance 2) and addition of 30.5 m manure application setback (Balance 3), minimum requirements of the USEPA CAFO regulations.

This option assumes the same situation as Balance 3 (base feeding program, N-based NMP, and setback) plus the export of 50% of manure production to off-farm uses.

^¶ This option assumes the same situation as Balance 3 (base feeding program, N-based NMP, and setback) plus the implementation of feeding program Option 1 (see Table 2).

..................................................