This page describes the functionality of each model within the OVERSEER^® nutrient budgets model.

Pastoral model

The pasture model has evolved into a resource tool to examine budgets of nutrients, greenhouse gases and energy use within a farm.

There are 2 pasture model modes, an express mode and a detailed mode.

Express mode
The express mode has been designed for farms with only 1 management block, or for a dairy farm with an effluent block. The nutrient budget produced is for the whole farm, and limited additional information is given in a summary report, including greenhouse gas emissions associated with N cycling, animal production, and fertiliser use.

Data can be transferred from the express mode to the detailed mode with the click of a button.

Detailed mode
The detailed mode has been designed to cover a range of farm nutrient inputs and outputs, or to change settings related to greenhouse gas emissions. Thus in the detailed mode, users can:

• have more than one block
	» change relative productivity between blocks » have different mixes of animals on different blocks
• include winter stock management options aimed to reduced N leaching • include Ca / Mg / Na supplementation of animals • access a stock unit calculator (also gives better methane inventory) • access a soil test database which will produce graphs of soil test values over time

Within the pastoral nutrient budget model there are a number of default settings that are suitable for most farms. In the detailed mode, the user can access advanced dialogs to change some of these settings.

The detailed mode produces reports of:

• nutrient budgets for N, P, K, S, Ca, Mg, Na and acidity
• maintenance recommendations for fertiliser P, K, S, Ca, Mg, Na and lime
• N summary report
• P summary report
• greenhouse gas report – emissions associated with N cycling, fertiliser, and energy use, use of supplements and animals (methane)
• energy report

For each report, there are links to show how to interpret the reports, and comments are shown if certain criteria are exceeded indicating potential problems with nutrient use (such as high environmental pollution risks).

The detailed mode also allows scenarios to be produced, where the results of different management/mitigation options can be compared. There are a range of preset options available which also account for likely changes in other farm management.

Crop model

Nutrient budgets for N, P, K, S, Ca, Mg, Na are produced for the following crops:

grain crops	Wheat, Barley, Maize, Oats
greens	Broccoli, Brussel Sprouts, Cabbage, Cauliflower, Lettuces, Spinach
legumes	Green Beans, Dried Beans, Lentils, Green peas, Dried peas
root crops	Kumara, Potatoes, Beets, Carrots, Parsnips
seed crops	Clover seed, Ryegrass seed
other crops	Onions, Tomatoes, Sweetcorn, Squash

An environmental N report and greenhouse gas emissions associated with N cycling, fertiliser use and fuel use are also shown.

Horticultural model

Nutrient budgets for N, P, K, S, Ca, Mg, Na are produced for kiwifruit or apple systems. An environmental N report and greenhouse gas emissions associated with N cycling and fertiliser use are also shown.