Apps Labs downloads.

Have you had a water test? What do your water test results mean? (.doc format)

Have you had a soil test? Soil test interpretations (.doc format) Explains how soil tests are carried out, how to understand your test results and how testing relates to soil fertility management.

Tim Apps’ PhD thesis Model based diagnosis of acid base disturbances in natural waters. This thesis describes a way towards investigating causes of water quality problems by analysing the pH buffer system.

Plant nutrients.

Nutrient deficiency symptoms. (pdf format) For each of the main plant nutrients provides a more in depth description of how a deficiency will affect a plant’s growth, health and appearance. Also discusses types of soils where some deficiencies are more likely to occur. With sources.

NSW Department of Primary Industries Plant nutrients in the soil. This article is a concise summary of the main plant nutrients, their role in the plant and effect when deficient, typical soils where deficiencies can occur and examples of fertilisers that can help to overcome deficiencies.

MC State Extension Soils and plant nutrients. Soils and plant nutrients. This is a very good article on soils designed for home gardeners. It covers a range of topics like soil physical and chemical properties, soil organic matter, soil testing, soil biology and plant nutrition and fertilisation.

Nutrients in plants. (pdf format) This document contains a collection of tables that show the typical levels of nutrients in some plants and farm products. This can sometimes be shown as the nutrients taken up as a plant grows and also as the nutrients removed as a crop is harvested.

Kansas State University Department of Agronomy Soil nutrients sources and uptake. This reference outlines not only the main plant nutrients but also the chemical forms that are taken up by plants. There is a section on how manures supply nutrients. The emphasis in the article is how plants take up nutrients from the soil. Therefore some of the main soil factors like nutrient holding capacity, and physical factors related to soil management are discussed. The example for Grain Sorghum is used to show how nutrient uptake changes with the growth of the plant.

Pasture growth rate case study. (.doc format) In this case study the growth rate of pasture on a dairy farm was measured over a period of 1 year. The actual pasture production for the year was then calculated.

Simple to understand summary of nitrogen fixation from Wikipedia Nitrogen fixation.

Detailed discussion of mycorrhizal fungi from Wikipedia Mycorrhizal fungi. Mycorrhizae are specialized fungi that grow close to a plants roots. They usually take some nutrition from the plant so they can grow but in return help supply the pant with water and nutrients.

University of Idaho, College of Agriculture and Life Sciences. Nutrients plants require for growth. Concise and detailed summary that includes amounts of each nutrient typically required by plants, the function of each nutrient, guidance on how to identify deficiencies and types of soils where deficiencies can occur. Written for Idaho soils but there are many general principles that are useful for Aus.

Fertilising plan for a dairy farm. (pdf format) This is the preliminary fertilising plan for a dairy farm at Ranceby in SW Gippsland. It is based on a soil test and allows for the contribution of nutrients from cow manure. Based on this information and after setting production goals the plan discusses foliar and granular fertiliser options and includes information on commercial products and formulations and calculations for application rates.

Montana State University. Nutrient uptake. A useful resource for information on nutrients removed per harvested ton by various crops including vegetables, field crops and grass. It also shows the relative accumulation of main nutrients for the same crops in their growth cycle.

Montana State University Extension Plant nutrient functions and deficiency and toxicity symptoms. A very comprehensive practical guide to identifying plant nutrient deficiencies and toxicities. Contains a detailed guide to deficiency symptoms including diagnostic charts and colour photos. Well worth downloading to keep as a resource.

Soil pH and nutrient availability. This resource shows the pH range for some typical types of soils. It also shows the connection between pH and nutrient availability to plants. This is sometimes called the Truog diagram. An important observation is that many trace elements (molybdenum is the exception) are most readily available at lower pH levels (often typical of many Australian soils). However many of the major nutrients are most available at higher pH levels.

List of C:N ratios and %N. Comprehensive list of materials, their nitrogen % by weight and C:N ratios. C to N ratios. (Download from Apps Labs original link not available).

Successful Farming Why the carbon to nitrogen ratio matters. Here’s why carbon to nitrogen ratio matters. A good concise explanation of the carbon : nitrogen ratio and how it is important. The emphasis is on cropping so the examples show carbon : nitrogen ratios for a selection of green manures and cover-crops.

National Centre for Appropriate Technology Sustainable soil management.. An excellent introduction to the basics of sustainable soils. Covers basic biology and management aspects.