Precision Agriculture – SS3 Horticulture and Crop Production Lesson Note (First Term)

Precision agriculture is a method of farming that uses technology to give each part of a farm, or each plant, exactly what it needs, in the right place at the right time.

Behavioural objectives

By the end of the lesson, students should be able to:

1. define precision agriculture;
2. describe the uses of soil, crop and climate sensors;
3. state how drones, GPS and satellites are used on the farm;
4. explain the roles of farm management software, the Internet of Things (IoT) and mobile apps;
5. list the advantages and limitations of precision agriculture.

What is precision agriculture?

Precision agriculture (also called precision farming or “satellite farming”) means doing the right thing, in the right place, at the right time.

• Old method: the farmer spreads fertiliser evenly over the whole field.
• The problem: one corner may be rich in nutrients while another is poor, so money and chemicals are wasted.
• Precision method: technology is used to treat each square metre, or each plant, on its own.
• Example: it is like a doctor giving a specific medicine to one patient instead of the same pill to everyone in the city.

How is precision agriculture different from conventional farming?

Conventional farming treats the whole field in the same way. Precision agriculture treats each part of the field according to its own need.

What are the steps in precision agriculture?

Precision agriculture follows a cycle of four steps that is repeated each season.

1. Collect data: sensors, drones and satellites gather information on soil, crops and weather.
2. Analyse data: farm management software turns the data into maps and advice.
3. Apply inputs: water, fertiliser, seeds or chemicals are given only where they are needed.
4. Check results: the farmer monitors the crop and adjusts the plan.

What are the types of sensors used on the farm?

There are three main types of sensors in precision farming: soil, crop and climate sensors. A sensor is a device that measures something humans cannot easily see or feel, and it can work 24 hours a day.

• Soil sensors: pushed into the ground to measure moisture, temperature and nutrient levels such as nitrogen or salt. They tell the farmer when to irrigate.
• Crop sensors: handheld or fixed on a tractor. They use light to “read” leaf colour and show that a plant needs fertiliser before the eye can see the problem.
• Climate sensors: measure humidity, wind speed and solar radiation inside and outside the greenhouse.

How do drones, GPS and satellites help the farmer?

Drones, GPS and satellites let a farmer check a large field, such as 100 acres of maize, from the air in a short time.

What are drones used for on the farm?

A drone (UAV, or unmanned aerial vehicle) is a small remote-controlled aircraft fitted with a camera.

• Scouting: flies over the farm to find weed patches, pest outbreaks or dry spots.
• Spraying: some larger drones carry a tank and spray only the affected spot, which saves chemicals.
• Mapping: makes 3D maps that show where water pools or where the land is too steep.

What are GPS and satellites used for on the farm?

The Global Positioning System (GPS) is a satellite-based system that gives the exact location of a place on Earth.

• Auto-steer: tractors use GPS to drive in straight lines. This stops overlapping (covering the same spot twice) and saves fuel.
• Location tagging: GPS records where soil samples or problems were found, so the farmer can return to the same spot.
• Satellite imagery: satellites photograph the Earth regularly. Farmers can get a “heat map” of crop health from space.

What do ICT tools do on the farm?

Information and Communication Technology (ICT) is the “brain” of precision agriculture because it connects the sensors and drones to the farmer.

• Farm management software: an app on a phone or laptop that receives data from sensors and drones, analyses it and gives the farmer a “to-do” list.
• Internet of Things (IoT): machines on the farm communicate with each other. A soil sensor can tell a water pump to switch on when the soil is dry, with no farmer present.
• Mobile apps and SMS: in many parts of Africa, farmers use them to get weather forecasts, market prices and farming advice.

What are the advantages of precision agriculture?

The main advantages of precision agriculture are lower costs, a cleaner environment, higher yields and less manual work.

1. Cost savings: the farmer buys only the seeds, water and fertiliser that are needed.
2. Environmental protection: fewer chemicals leak into rivers and underground water.
3. Higher yields: plants that get exactly what they need produce more food.
4. Less manual work: technology does the repeated work of monitoring, so the farmer can focus on decisions.

What are the limitations of precision agriculture?

The limitations are mainly cost, skills and infrastructure, which affect many Nigerian farmers.

• High cost: sensors, drones and GPS tractors are expensive to buy and repair.
• Skills needed: farmers must be trained to use the devices and read the data.
• Power and network: devices need electricity and a good phone or internet network, which are not available in every village.
• Small farms: some tools suit large farms better than small plots.

Evaluation

1. What is precision agriculture?
2. Name three types of sensors used on a farm and state what each one measures.
3. State three ways in which drones are used in precision agriculture.
4. How does auto-steer save fuel?
5. Explain how the Internet of Things (IoT) can switch on a water pump without the farmer being present.

Assignment

List four advantages of precision agriculture and explain each one in one or two sentences.