Northeast Region Certified Crop Adviser (NRCCA) Study Resources

In This Section

• Introduction
• PO 44 Setting a realistic goal
• PO 45 Determining crop nutrient needs
• PO 46 Environmental effects of nutrient loss
• PO 47 NRCS 590 nutrient management standard
• PO 48 Mass nutrient balance
• PO 49 P-based vs. N-based manure application
• PO 50 Surface application and immediate incorporation of manure
• PO 51 Precision feeding
• PO 52 Environmentally sensitive areas
• PO 53 Nutrient management plans
• PO 54 Calculate total manure production
• PO 55 Capacity factors in manure storage
• PO 56 Three option for P management
• PO 57 The P index
• PO 58 Impacts of practice on P index
• PO 59 Calculate crop P removal
• PO 60 Nitrate leaching index (LI)
• PO 61 Practices to reduce nitrate leaching
• PO 62 Manure odor issues
• PO 63 Agricultural air quality
• PO 64 Reducing pathogen concerns from manure
• Summary

Competency Area 6: Nutrient Management and Planning

PO 60. Understand the nitrate Leaching Index (LI) principles and interpretations.

The nitrate Leaching Index is an indicator of the potential for nitrate to reach groundwater.  The current LI rates leaching potential based on soil hydrologic group and precipitation data.

• LI < 2: low risk of nitrate leaching below the root zone
• 2 < LI < 10: intermediate risk of nitrate leaching below the root zone
• LI > 10: high risk of nitrate leaching below the root zone

To meet the N leaching requirements of the NRCS Nutrient Management Standard (590), producers are expected to implement Best Management Practices (BMPs) if the LI score for a field is high, and to consider BMPs if the LI score is intermediate.  Sample BMPs are discussed in PO 61.

NY soil types and hydrologic groups can be obtained from the New York Nitrate Leaching Index (particularly here and here).