CONTENTS

• What is Precision Agriculture?
  • The first definition 
  • The second definition
• Benefits of Precision Agriculture 
•  General Adoption Path
  • Stage 1. Optimize uniform-rate crop management, and to improve farming efficiency
  • Stage 2. Measure where and how much crop production varies across fields, the farm and seasons
  • Stage 3. Determine the major causes of the variability
  • Stage 4. Optimize the use of inputs and maximize my gross margin, while minizing environmental footprint
  • Stage 5. Improve grain quality control and product marketing
• Misconceptions about Precision Agriculture

What is Precision Agriculture?

Precision Agriculture (PA) has become a widely recognized term in agricultural practices globally. However, what exactly does Precision Agriculture entail? This introductory module offers insight into the development of PA, its core principles, objectives of a PA management approach, and the necessary steps for implementing PA in cropping systems.

Precision Agriculture (PA) encompasses various definitions and interpretations, reflecting the diversity of views within the agriculture sector. 

The first definition 

One notable definition from the US House of Representatives emphasizes PA as:

“An integrated information- and production-based farming system that is designed to increase long term, site-specific and whole farm production efficiency, productivity and profitability while minimising unintended impacts on wildlife and the environment”.  

The key to this definition is that it idenfities PA as a 'whole-farm' management strategy, incorporating information technology to manage production and environmental impact across the entire farm, not just individual fields. While historically associated with cropping industries, PA principles are applicable to diverse agricultural sectors, including animal husbandry, horticulture, viticulture, fisheries, and forestry, where techniques align with PA objectives, such as precision feeding in dairy production, where feed allocations for individual cows are tailored based on yield and lactation stage. 

In this series of modules, the focus is on the implementation of PA in the grains industry.

The second definition

Within the context of cropping systems, Site-Specific Crop Management (SSCM) captures the essence of PA by refining resource allocation and agronomic practices to suit varying soil and crop conditions within fields. This definition underscores PA as a dynamic management strategy focused on decision-making related to resource use, rather than merely adopting technology. Improved decision-making through SSCM promises a spectrum of benefits—economic, environmental, and social—whose full extent may not yet be fully quantifiable. 

This definition serves as a clear goal for Australian grain growers, emphasizing the utilization of information technologies at a site-specific level alongside grower expertise to:

1. optimize production efficiency;

2. optimize quality, 

3. minimize environmental impact, and 

4. minimize risk

Figure 1. The economic and environmental foundation for a site-specific management system to minimize operational risk.

The evolution of SSCM represents a shift in agricultural practice, enabled by technological advancements, from a historical focus on large-scale uniform practices towards site-specific management while retaining economies of scale. This transition is significant, as it allows for a more nuanced understanding and management of variability within agricultural systems, enhancing productivity and sustainability. While the principles of SSCM are not novel, the contemporary scale at which they can be implemented marks a pivotal moment in agricultural history, offering opportunities to address operational challenges and optimize resource utilization in modern farming practices.

Benefits of Precision Agriculture

 1. Overcoming potential problems

A one-size-fits-all application of agronomic decisions and physical inputs across large cropping areas can lead to potential problems due to the variability inherent in cropping systems, as shown on the table below:

Table 1. Potential problems expected when 'uniform' treatment is applied to influential cropping system components that vary across a cropping area.

2. Differential management

Differential management, involving the application of decisions and inputs in varying degrees, offers a solution. Variable-rate application (VRA) using variable-rate technology (VRT) is a prominent form of this approach. Differential treatment options include varying rates, types, placements, and timings of inputs. For instance, controlled-traffic operations in farming, targeting specific parts of a paddock, can benefit soil condition and crop growth.

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3. Potential management classes (PMC)

The concept of differential treatment extends to potential management classes (PMC), where different areas of a field may require distinct management practices based on varying yield potentials. Trials can reveal significant differences in crop responses to inputs across these classes. 

For example, consider the a wheat crop trial to test whether there is a measurable difference in the response to nitrogen (N) in two potentially different management classes in a 195-acre (79-hectare) field. The uniform rate of 60kg N/ha was applied to the field. After measuring yield in trial plots, the two potential management classes showed significantly different responses, with the optimum rates being at least 89.2 lb N/a (100kg N/ha) for class 1 and 34.8 lb N/a (39 kg N/ha) for class 2 (Figure 2).

In response to the variability observed, nitrogen management could be modified in different ways:

• Scenario 1 
  •  maintain the same total amount of N fertilizer to the field (195a x 53.5lb N/a | 79ha x 60kg N/ha)
  •  redistribute fertilizer from class 2 (-18.78 lb/a | -21 kg/ha) to class 1 (+18.78 lb/a | +21 kg/ha)

• Scenario 2 
  • apply closer to the correct amount to each class, which would require an additional 1.4t of N to cover the increased application in class 1, in addition to the fertilizer redistributed from class 2. 

Figure 2: Field response to applied N fertiliser in two management classes. Average uniform paddock application was 60kg N/ha. Class 1 optimum = 100kg N/ha; Class 2 optimum = 39kg N/ha.

4. Environmental gains

Precision agriculture (PA) not only offers economic benefits but also environmental gains by reducing the environmental risks associated with uniform treatments. By working with the natural diversity in cropping systems, PA can enhance both economic and environmental efficiencies.  

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 General Adoption Path

The adoption of PA should follow the optimization of existing uniform farm management practices. This sequential approach ensures larger gains by fine-tuning production management before implementing PA. Ultimately, aligning yield goals with measured variation in yield potential across cropping areas can enhance the sustainability of modern cropping systems.

Below is an indicative outline of progressively incorporating precision agriculture in your farming operation:

Stage 1. Optimize uniform-rate crop management, and to improve farming efficiency

Stage 2. Measure where and how much crop production varies across fields, the farm and seasons

Stage 3. Determine the major causes of the variability

Stage 4. Optimize the use of inputs and maximize my gross margin, while minizing environmental footprint

Stage 5. Improve grain quality control and product marketing

Misconceptions about Precision Agriculture

Misconception # 1: "Yield mapping is the same as precision agriculture"

 - Yield mapping is a tool which serves as one of the first steps towards implementing a site-specific crop management strategy (SSCM).

Misconception #2: "Precision agriculture is the same as sustainable agriculture"

- Precision agriculture is a tool to help make agriculture more sustainable, however it is not the total solution. 

PA aims to have maximum product efficiency with minimum environmental impact. Initially, it was the potential for improved productivity and profitability that drop the development of SSCM as a form of PA.

In recent years, the potential for this technology as a tool for environmental auditing of production systems has become more imminent. The large amount of fine-scale data being collected in a SSCM system can be used for on-farm environmental risk assessment and incorporated into a whole-farm plant to help viability in the long term.

Misconception #3: "I am already doing PA. My tractor is fitted with an autosteer system"

- Machinery guidance and autosteer systems are examples of successful adoption of new technology on farms. However, these are tools that help with SSCM. By themselves, they are not PA.