Editing Nutrient management (section)

==Nutrient management plan==
[[Image:Epandeur de Fumier Rolland.JPG|right|thumb|[[Manure spreader]]]]
A crop '''nutrient management plan''' is a tool that [[farmer]]s can use to increase the efficiency of all the nutrient sources a crop uses while reducing production and [[environmental risk]], ultimately increasing [[profit (economics)|profit]]. Increasingly, growers as well as agronomists use digital tools like SST or [[Agworld]] to create their nutrient management plan so they can capitalize on information gathered over a number of years.<ref>{{Cite web|url=https://www.precisionag.com/digital-farming/the-digital-farm-how-precision-technologies-are-helping-farmers-increase-profitability-meet-demand-for-nutritious-calories/|title = The Digital Farm: How Precision Technologies Are Helping Farmers Increase Profitability, Meet Demand for Nutritious Calories|date = 24 June 2019}}</ref> It is generally agreed that there are ten fundamental components of a crop nutrient management plan. Each component is critical to helping analyze each field and improve nutrient efficiency for the crops grown. These components include:<ref>[http://extension.psu.edu/plants/nutrient-management/educational/nutrient-management-general/nutrient-management-planning-an-overview Nutrient Management Planning: An Overview]</ref>
;[[Field map]]: The map, including general reference points (such as streams, residences, wellheads etc.), number of acres, and soil types is the base for the rest of the plan.
;[[Soil test]]:  How much of each nutrient (N-P-K and other critical elements such as pH and organic matter) is in the soil profile? The soil test is a key component needed for developing the nutrient rate recommendation.
;[[Crop sequence]]:  Did the crop that grew in the field last year (and in many cases two or more years ago) fix nitrogen for use in the following years? Has long-term no-till increased organic matter? Did the end-of-season stalk test show a [[Plant nutrition#Nutrient deficiency|nutrient deficiency]]? These factors also need to be factored into the plan.
;Estimated yield:  Factors that affect yield are numerous and complex. A field's soils, [[drainage]], insect, [[weed]] and [[plant disease|crop disease]] pressure, rotation and many other factors differentiate one field from another. This is why using historic yields is important in developing yield estimates for next year. Accurate yield estimates can improve nutrient use efficiency.
;Sources and forms:  The sources and forms of available nutrients can vary from farm-to-farm and even field-to-field. For instance, [[manure]] fertility analysis, storage practices and other factors will need to be included in a nutrient management plan. Manure nutrient tests/analysis are one way to determine the fertility of it. [[Nitrogen fixation|Nitrogen fixed]] from a previous year's [[legume]] [[Green manure|crop]] and residual effects of manure also affects rate recommendations. Many other nutrient sources should also be factored into this plan. 
;Sensitive areas:  What's out of the ordinary about a field's plan? Is it irrigated? Next to a stream or lake? Especially sandy in one area? Steep slope or low area? Manure applied in one area for generations due to proximity of dairy barn? Extremely productive—or unproductive—in a portion of the field? Are there buffers that protect streams, drainage ditches, wellheads, and other [[water collection]] points? How far away are the neighbors? What's the general wind direction? This is the place to note these and other special conditions that need to be considered.
;Recommended rates: Here's the place where science, technology, and art meet. Given everything you've noted, what is the optimum rate of N, P, K, lime and any other nutrients? While science tells us that a crop has changing [[nutrient requirements]] during the growing season, a combination of technology and farmer's management skills assure nutrient availability at all stages of growth. No-till corn generally requires starter [[fertilizer]] to give the seedling a healthy start.
;Recommended timing: When does the soil temperature drop below 50 degrees? Will a N stabilizer be used? What's the tillage practice? Strip-till corn and no-till often require different timing approaches than seed planted into a field that's been tilled once with a field cultivator. Will a starter fertilizer be used to give the seedling a healthy start? How many acres can be covered with available labor (custom or hired) and equipment? Does manure application in a farm depend on a custom applicator's schedule? What agreements have been worked out with neighbors for manure use on their fields? Is a neighbor hosting a special event? All these factors and more will likely figure into the recommended timing.
;Recommended methods: Surface or injected? While injection is clearly preferred, there may be situations where injection is not feasible (i.e. pasture, grassland). Slope, rainfall patterns, soil type, [[crop rotation]] and many other factors determine which method is best for optimizing nutrient efficiency (availability and loss) in farms. The combination that's right in one field may differ in another field even with the same crop.
;Annual review and update: Even the best managers are forced to deviate from their plans. What rate was actually applied? Where? Using which method? Did an unusually mild winter or wet spring reduce soil nitrate? Did a [[drought|dry summer]], disease, or some other unusual factor increase nutrient carryover? These and other factors should be noted as they occur.

When such a plan is designed for [[animal feeding operations]] (AFO), it may be termed a "manure management plan." In the United States, some regulatory agencies recommend or require that farms implement these plans in order to prevent [[water pollution]]. The U.S. [[Natural Resources Conservation Service]] (NRCS) has published guidance documents on preparing a comprehensive nutrient management plan (CNMP) for AFOs.<ref>NRCS. Beltsville, MD. [https://www.nrcs.usda.gov/technical/afo/pdf/CNMPFactSheet.pdf "Comprehensive Nutrient Management Plans."] Fact Sheet. 2003.</ref><ref>NRCS. [https://www.nrcs.usda.gov/technical/afo/cnmp_guide_index.html "National Planning Procedures Handbook: Draft Comprehensive Nutrient Management Planning Technical Guidance."] Subpart E, Parts 600.50-600.54 and Subpart F, Part 600.75. December 2000.</ref>

The International Plant Nutrition Institute has published a 4R [[plant nutrition]] manual for improving the management of plant nutrition. The manual outlines the scientific principles behind each of the four Rs or "rights" (right source of nutrient, right application rate, right time, right place) and discusses the adoption of 4R practices on the farm, approaches to nutrient management planning, and measurement of sustainability performance.<ref>[http://www.ipni.net/article/IPNI-3255 4R Plant Nutrition Manual]</ref>