The Nitrate Leaching Calculator uses the conservation of mass to estimate potential nitrate leaching simulations of various management scenarios.

-The Field Management option allow for comparing impacts of two management scenarios within a field.

-The Rotation Management option allows for simulation of nitrate leaching losses from one field over the course of a four year rotation.

Use of the app requires knowledge of various inputs such as yield, fertilizer, soil type, etc. The Nitrate Leaching Calculator is based off of work by Meisenger and Randall (1991) and users would benefit from reading their work to better understand all of the underlying assumptions. It is going to be more accurate when actual yields are used rather than yield goals. As a result it is more appropriate to think of this as a hindcasting model to understand the potential leachable N at the end of the time period rather than a predictive tool. Many of the assumptions are based on the calculator being used for typical Wisconsin agricultural systems and climate.

Meisinger, J.J., Randall, G.W., 1991. Estimating Nitrogen Budgets for Soil-Crop Systems. Managing Nitrogen for Groundwater Quality and Farm Profitability, pp. 85-124.

What information do you need:

1. Soil organic matter content

2. Soil drainage classification

3. Soil pH

4. Nitrogen inputs (i.e. nitrogen fertilizer, manure, or other biosolid application rates)

5. Information on fertilizer form and application method

6. Crop type and yield

7. If irrigated, irrigation nitrate concentration and amount applied

8. If cover crop was grown, type of cover crop and biomass estimate

The Rotation Management: Nitrate Leaching Calculator uses the conservation of mass to estimate potential nitrogen leaching. for comparison of different years in a rotation on the same field. The tool relies on user knowledge of various inputs such as yield, fertilizer, soil type, etc. Other factors are assigned using tables and other assumptions outlined in Meisenger and Randall (1991).

Using this tool:

1. Enter information about soils and other environmental conditions.

2. Enter information about crop and nitrogen inputs for up to two management scenarios.

3. If field is irrigated and/or cover crop was grown, click yes to enter information.

4. If simulating the impact of altering a management practice on a portion of the field, enter the acreage for each scenario. The calculator will estimate a weighted leaching loss/nitrate concentration based on the acreage.

5. Scroll down to the bottom of the page to view your Nitrogen Budget.

For more information about various data inputs, hover over the 'i' next to the field name.

Field Management: When using the Nitrate Leaching Calculator to simulate field management, the calculator allows for comparison of two management scenarios. By entering acreage it allows you to estimates a field based flow-weighted mean nitrate concentration relative to the proportion of each management scenario on a field and the overall water quality impact below the field.

The tool relies on user knowledge of various inputs such as yield, fertilizer, soil type, etc. Other factors are assigned using tables and other assumptions outlined in Meisenger and Randall (1991).

Using this tool:

1. Enter information about soils and other environmental conditions.

2. Enter information about crop and nitrogen inputs for up to two management scenarios.

3. If field is irrigated and/or cover crop was grown, click yes to enter information.

4. If simulating the impact of altering a management practice on a portion of the field, enter the acreage for each scenario. The calculator will estimate a weighted leaching loss/nitrate concentration based on the acreage.

5. Scroll down to the bottom of the page to view your Nitrogen Budget.

For more information about various data inputs, hover over the 'i' next to the field name.