Abstract
The application of organic materials is one of the most effective ways of increasing soil organic carbon (SOC) levels and improving soil quality. However, it is possible that not all forms of organic matter input have the same impact on soil properties. The purpose of this review is to synthesise this information to provide a perspective for this project. The information should guide our analysis when organics are used as fertilizers in our study areas. And to assess potential usefulness of any other type of organics that can be identified from the literature.
The application of organic materials to agricultural soils has multiple benefits, not only as a source of essential plant nutrients which can provide savings in inorganic fertilizer use (Defra, 2010), but also as a means of increasing soil organic carbon (SOC) levels that can improve the soil biological and physical functioning (Bhogal et al., 2009). The benefits from a range of organic material applications (such as livestock manures, composts, biosolids, food wastes, biochar, etc.) for SOC and soil quality have been documented and reviewed in literature (e.g., Edmeades, 2003; Johnston et al., 2009). Studies have also been conducted to evaluate the potential of organic materials as nutrient sources (Schröder et al., 2005) and soil conditioners (Diacono and Montemurro, 2010), as well to sequester carbon (C) in the mitigation of climate change (Powlson et al., 2012).
Soil nutrient management and circular economy principles have led to increasing amounts of organic materials being directed away from landfill and beneficially recycled to agricultural land, to complete natural nutrient and C cycles. In order to provide confidence in the use of these materials within agricultural systems, it is important to demonstrate their long-term effects on soil and food quality as well as developing sustainable nutrient management practices by minimizing environmental losses (Bhogal et al., 2016; Nicholson et al., 2017).
Do all organic carbon (OC) inputs have the same impact on soil properties regardless of the source? It may depend on the amount of organic material (C) applied, but not on the type of material. For example, changes in the total SOC pool have been shown to depend on the amount of organic material (C) applied, not on the type of organic carbon inputs (e.g., Rasmussen et al., 1980). However there are evidence on the response of other soil properties to the type of material applied. For example, Bhogal et al. (2009) observed that repeated OC inputs (for at least 7 years) in the form of livestock manures led to improvements in soil physical properties (bulk density, porosity, and available water capacity) whereas OC additions in the form of crop residues (straw) did not. Further, the soil quality benefits of organic materials can depend on the amount (number of applications × OC content) or on the form of OC applied.
This project will assess economic feasibility of using nutrient-enriched organic fertilizers derived from waste materials (e.g. poultry/pig manure, dairy farm wastes, composts, mulches, biochar) in broadacre/other cropping systems in selected case study areas of NSW. While the biophysical benefits of incorporating organic wastes as fertilizers into soils are known, the financial impacts as less well understood and documented. In particular, the wider and combined financial impacts of organic material as fertilizer are poorly understood and communicated to farmers. This project will address a recognized need by helping farmers understand the economics of applying organic amendments derived from waste streams. Because this requires data that are dispersed or absent.
The project will synthesize information from review of literature, interviews with stakeholders, and Agricultural Production Systems Simulator (APSIM) modelling. From these a draft decision framework and guiding tool will developed. This will be demonstrated, tested and refined through a workshop with farmers.
The purpose of this report is to review any study, in any context, conducted within the scope of this project. And to synthesise this information to provide a perspective for this project. The information from above should guide our analysis when organics are used as fertilizers in our study areas. And to assess potential usefulness of any other type of organics that can be identified from literature.
Section 2 provides an overview of the level of inorganic fertilizers use in Australia and their impacts. Section 3 outlines the benefits of organics and the examples for different types of organics used in Australian cropping systems. A model for decision on the level of organics use is illustrated in Section 4. The proposed methodology for this study is described in Section 5. The details of the case study areas (and/or businesses) selected are given in Section 6. Preliminary results from APSIM simulations are presented in Section 7, followed by a summary in Section 8.
The application of organic materials to agricultural soils has multiple benefits, not only as a source of essential plant nutrients which can provide savings in inorganic fertilizer use (Defra, 2010), but also as a means of increasing soil organic carbon (SOC) levels that can improve the soil biological and physical functioning (Bhogal et al., 2009). The benefits from a range of organic material applications (such as livestock manures, composts, biosolids, food wastes, biochar, etc.) for SOC and soil quality have been documented and reviewed in literature (e.g., Edmeades, 2003; Johnston et al., 2009). Studies have also been conducted to evaluate the potential of organic materials as nutrient sources (Schröder et al., 2005) and soil conditioners (Diacono and Montemurro, 2010), as well to sequester carbon (C) in the mitigation of climate change (Powlson et al., 2012).
Soil nutrient management and circular economy principles have led to increasing amounts of organic materials being directed away from landfill and beneficially recycled to agricultural land, to complete natural nutrient and C cycles. In order to provide confidence in the use of these materials within agricultural systems, it is important to demonstrate their long-term effects on soil and food quality as well as developing sustainable nutrient management practices by minimizing environmental losses (Bhogal et al., 2016; Nicholson et al., 2017).
Do all organic carbon (OC) inputs have the same impact on soil properties regardless of the source? It may depend on the amount of organic material (C) applied, but not on the type of material. For example, changes in the total SOC pool have been shown to depend on the amount of organic material (C) applied, not on the type of organic carbon inputs (e.g., Rasmussen et al., 1980). However there are evidence on the response of other soil properties to the type of material applied. For example, Bhogal et al. (2009) observed that repeated OC inputs (for at least 7 years) in the form of livestock manures led to improvements in soil physical properties (bulk density, porosity, and available water capacity) whereas OC additions in the form of crop residues (straw) did not. Further, the soil quality benefits of organic materials can depend on the amount (number of applications × OC content) or on the form of OC applied.
This project will assess economic feasibility of using nutrient-enriched organic fertilizers derived from waste materials (e.g. poultry/pig manure, dairy farm wastes, composts, mulches, biochar) in broadacre/other cropping systems in selected case study areas of NSW. While the biophysical benefits of incorporating organic wastes as fertilizers into soils are known, the financial impacts as less well understood and documented. In particular, the wider and combined financial impacts of organic material as fertilizer are poorly understood and communicated to farmers. This project will address a recognized need by helping farmers understand the economics of applying organic amendments derived from waste streams. Because this requires data that are dispersed or absent.
The project will synthesize information from review of literature, interviews with stakeholders, and Agricultural Production Systems Simulator (APSIM) modelling. From these a draft decision framework and guiding tool will developed. This will be demonstrated, tested and refined through a workshop with farmers.
The purpose of this report is to review any study, in any context, conducted within the scope of this project. And to synthesise this information to provide a perspective for this project. The information from above should guide our analysis when organics are used as fertilizers in our study areas. And to assess potential usefulness of any other type of organics that can be identified from literature.
Section 2 provides an overview of the level of inorganic fertilizers use in Australia and their impacts. Section 3 outlines the benefits of organics and the examples for different types of organics used in Australian cropping systems. A model for decision on the level of organics use is illustrated in Section 4. The proposed methodology for this study is described in Section 5. The details of the case study areas (and/or businesses) selected are given in Section 6. Preliminary results from APSIM simulations are presented in Section 7, followed by a summary in Section 8.
| Original language | English |
|---|---|
| Place of Publication | Australia |
| Publisher | Soil CRC |
| Commissioning body | Cooperative Research Centre for High Performance Soils |
| Number of pages | 46 |
| Publication status | Published - 30 Jun 2023 |
Grant Number
- RM 103706
