Nutrient Management Planning for Livestock Production
It is recommended that livestock operations should develop and implement comprehensive, site-specific manure and nutrient management plans (Bennett et. al. 1995). Nutrient management refers to the balancing of nutrients in fertilizers, manure, and soil with the requirements of the crop, to enhance the economic and environmental sustainability of production agriculture (West 1996a). An efficient nutrient management plan is one that is environmentally sound, maximizes crop benefits and feed quality, minimizes nutrient loss during collection, storage and application, and maximizes nutrient utilization by crops (Chizmazia 1996).
Nutrient management should be integrated with cropping, tillage, and soil-water management and should become a component of the overall conservation plan. When planning nutrient management, the implementation and management activities must be in-line with other objectives of the conservation management plan. For example, incorporation of manure to conserve nutrients and reduce odour may conflict with crop residue requirements in a reduced or no-till conservation tillage system.
Nutrients applied in manure, plus those of purchased nutrients, should not exceed the nutrient requirements of the crop (Janzen and McGill 1997). The ratio of nitrogen (N), phosphorus (P) and potassium (K) found in manure is variable depending on animal species, feed content and storage method. In general, manure ratios of plant available N-P2O5-K2O are between 3-2-3 and 2-1-2. This contrasts with what plants require for growth, which is between 8-1-3 and 3-1-2. An imbalance exists between nutrient requirements of the crop and nutrient supply in manure (USDA-NRCS 1999).
The amount of N and P purchased as fertilizer in Alberta is about twice as much as that excreted as manure, but fertilizer is applied to over 16-times more land. This indicates that the large amounts of manure nutrients produced in Alberta are spread on relatively small areas of land, causing the potential for excessive losses of N and P, and increased accumulations of soil test P (Janzen and McGill 1997). Losses of nitrogen and phosphorus, and accumulations of soil-test phosphorus, both represent ineffective use, or waste, of manure nutrients. Nutrient loss tends to increase as nutrient loading of a soil increases.
Nutrient Management Plan Components
There are a number of steps to a nutrient management plan depending on the size of the operation. The steps are not intended to be all-inclusive but are considered the minimum requirement for the nutrient management component of the overall conservation plan. Record keeping is critical. For example, recording the manure spreading time and rate on each field is one way to avoid long term over application, and to be able to provide necessary proof when disputes arise.
Forms, worksheets, maps, and photography can all be used to develop the nutrient management component for an individual operation. Nutrient management planning is not required currently by legislation in Alberta, but a number of municipalities recommend or request new developments complete a nutrient management plan to effectively manage farm manure.
The nutrient management plan for a particular operation can incorporate the following items and critical steps, but each nutrient management plan will be unique (to some degree) for each individual farm operation.
Plan Identification, the plan should contain:
Map or Aerial Photograph (e.g.1:5000), the plan should identify the:
Plan Elements: Items to include in the records may include (adapted from Safley 1994):
|Livestock population||Land receiving waste|
|Schematic of production facilities||Cropping plan|
|Nutrition documentation||Field records|
|System design||Soil, manure, water and crop samples|
|Permit file||Well monitoring records|
|Management calendar||Location of sensitive areas or resources|
|Manure storage system||Soil information|
|Minimum distance separation maps||Recommendations|
The 10 critical steps to building a nutrient management plan are (adapted from Ontario Ministry of Agriculture, Food and Rural Development 1997):
1) Test your manure
2) Test your soil
3) Account for residual nutrients from previous legume crops and manure application
4) Select how and when to apply manure, and the time before incorporation
5) Select fields and determine application rates
6) Choose your supplemental fertilizers
7) Calibrate your spreader
8) Be aware of sensitive areas and follow beneficial management practices
9) Inventory and document your nutrients
10) Conduct a yearly review of your plan