Page 73 - Nutrient Management Planning Guide

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Field Assessment

Redistribution of nutrients and surface water flow patterns due to topography will influence productivity, creating areas of higher and lower productivity within a field. This presents an opportunity to use landscape specific management strategies such as management zoning and variable rate nutrient application. These strategies offer the potential for controlled nutrient placement to optimize utilization, minimize accumulation, and decrease the risk of loss.

Water Bodies

The location of water bodies, in or adjacent to fields that receive nutrient application, is a critical feature to identify during a site assessment. Water bodies include, but are not limited to:

active or abandoned wells • springs • sloughs • lakes • rivers • streams • aquifers • wetlands •

Management Implications »

Whenever nutrients are applied near a water body there is a potential risk to water quality. According to AOPA, manure application setbacks apply only to “common bodies of water”—i.e., water bodies that are not entirely contained on land controlled by a landowner. However, for good environmental stewardship it is important to protect all water bodies.

Problem Soil Conditions

Problem soil conditions can limit the productive potential of a site. Some common conditions that should be identified include:

Salt-affected soils • Soil pH • Solonetzic soils • Organic soils • Eroded soils •

Salt-Affected Soils

Saline soils have high concentrations of soluble salts in surface soil layers. These soils are identified through a combination of soil testing and visual inspection of a site.

Management Implications »

Soil salinity can limit crop yield by impairing a crop’s ability to efficiently use soil moisture. Crops vary in their sensitivity to saline conditions. Salt-sensitive crops have less yield potential and lower nutrient requirements than more salt-tolerant crops. It may be advantageous to include more salt-tolerant perennial species such as tall and slender wheatgrass in rotations. Six-row barley is the most tolerant annual crop followed by two-row barley, canola and wheat. Depending on the cause of the salinity issue, specific management to address recharge and discharge sites within the field may be required.

The salt tolerance of various crops grown in Alberta is presented in Table 3.4.5 (Chapter 3.4).

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The generalized pH classification of soils is discussed in Chapter 3.4.

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