Page 231 - Nutrient Management Planning Guide

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Chapter 6.1

If eligible land base exceeds manure supply the issue then becomes how to prioritize fields for application to maximize economic benefit. Fields can be prioritized based on:

distance to field from storage • fertility requirements (e.g., high nutrient use crops, •

high fertilizer recommendations) value of the crop to be grown • the presence of degraded soils (e.g., eroded areas, •

low organic matter, poor tilth) that would benefit from manure application the desire to minimize nuisance to neighbours or •

environmental risk accessibility or flexibility in crop management •

Distance from the storage site to the application site is probably the biggest single factor influencing the economics of manure usage. In most situations, fields closest to the manure source are manured the most. For operations with a history of manure application, however, applying manure to fields further away may help to reduce nutrient build-up in fields closer to the manure source. In addition, this may help to extract greater economic benefit from manure nutrients since they will be used to support crop growth rather than contributing to nutrient surpluses in soil.

Crops with higher economic value (e.g., canola) may yield greater economic returns from the nutrients applied than lower value crops (e.g., oats). Degraded or poor quality soils can often benefit the most from manure application. This is due to soil building properties of manure as well as nutrient content, which help to improve the general productivity of these areas.

Fields may also be prioritized so as to minimize odour complaints from neighbours. Selecting fields with minimal natural environmental risk (e.g., slope or proximity to water bodies or other sensitive areas) is another strategy for prioritizing fields for application. Different cropping scenarios (e.g., silage production, fall cereals, forages) may offer potential for flexibility in manure allocation strategy. Fields that are drier earlier in the season may be given priority so manure application can begin earlier in the spring, reducing compaction issues and taking advantage of released nutrients.

Determining Whether Land Base is Sufficient »

A simple calculation can help a producer determine whether the eligible land base will be sufficient to accommodate annual manure production:

Threshold Application Rate =

Annual Manure Production ÷ Eligible Application Area

Based on the application strategy selected, if manure is applied at rates higher than this threshold, the eligible area will be sufficient. If manure is to be applied at a rate lower than this threshold, additional area will be required.