Water – our most precious natural resource – is coming under threat and scientists warn that water scarcity is going to face further pressure from the growing effects of climate change. Tanks for Everything stress the importance of recycling water and explain how “there is simply not enough usable water in the world and the pressure on groundwater reserves is an issue across the globe.” It is therefore important that we find ways to reuse and recycle the water we have available, in order to secure water supply for future generations.
Using wastewater irrigation in agriculture is one way to achieve this. Wastewater can be easily collected or pumped directly from a nearby water source. It can then be used to irrigate crops and fields. According to a report by ROWA more than 20 million hectares are currently being irrigated with wastewater worldwide by about 200 million farmers. Below, we are going to look at what irrigation is, and the main benefits of using wastewater irrigation in agriculture.
What is irrigation?
The Food and Agriculture Organisation define irrigation as “the artificial application of water to soil for the purpose of supplying the moisture essential for plant growth.” Agriculture Victoria explain how effective irrigation will influence the entire growth process from seedbed preparation, germination, root growth, nutrient utilisation, plant growth, yield and quality. Irrigation is therefore an extremely important process in agriculture across the globe. There are many different types of irrigation systems available, this includes:
- Flood irrigation – When water is applied over the entire field to infiltrate into the soil.
- Sprinkler irrigation – When water is applied in the form of a spray so that it reaches the soil very much like rain. The rate of application is adjusted to prevent it from creating a pond of water on the surface.
- Localised irrigation – When water is distributed under low pressure, through a piped network and applied to each plant individually.
- Drip irrigation – When drops of water are delivered at or near the root of plants. In this type of irrigation, evaporation and runoff are minimised.
- Centre pivot irrigation – When water is distributed by a system of sprinklers that move on wheeled towers in a circular pattern.
- Manual irrigation – When water is applied to plants manually using watering cans or buckets. This is the most time-consuming and labour-intensive form of irrigation.
The type of irrigation system used will depend on a number of factors. These include, variations in soil types, availability of water and power sources, the size of the area needing irrigation. In addition, factors to consider include, the availability of financial resources, and how long the irrigation system has been installed.
What are the benefits of using wastewater irrigation in agriculture?
Using wastewater to irrigate crops and farmland has a number of benefits, this includes:
- High nutrient content – Wastewater has a naturally high nutrient content which reduces or even eliminates the need for expensive chemical fertilisers. This helps to support people in poorer communities by reducing agricultural running costs.
- Environmentally friendly – Using wastewater to irrigate crops and farmland is a sustainable practice that helps to reduce water wastage and conserve water supply.
- Higher production of crops – Irrigation allows farmers to grow more pastures and crops by providing access to water. Particularly at times when it would otherwise be hard to achieve good plant growth. Having access to water throughout the year also lengthens the growing season. In addition, irrigation allows farmers to grow crops in areas that would otherwise be considered too dry. It provides ‘insurance’ against seasonal variability and drought.
- Better quality crops – Irrigation allows farmers to produce higher quality crops and pastures as water stress can dramatically impact on the quality of farm produce.
- Increase the value of the property – Irrigated land has the potential to support higher crops and animal production. It is therefore more valuable. This means that having an irrigation system in place often improves the value of the property.
Our planet does not have infinite resources of water and it won’t last forever. It is therefore essential that we recycle the water we have, in order to secure supply for future generations. Wastewater and all of the other materials that go down the drain are a veritable treasure trove of select raw materials. This resource can irrigate gardens and agricultural fields, or replenish surface water and groundwater. Water recycling is an environmentally and economically viable solution to help conserve our water resources.