Irrigation systems have become the backbone of agriculture. It can provide water for plant growth, maintain landscapes, and rejuvenate disturbed soils in areas that are historically dry and have less rainfall. There are different types of irrigation systems – Surface Irrigation, Sprinkler Irrigation, and Drip Irrigation. However, these days the most widely used irrigation system for saving water is drip irrigation. It has proven to be much more effective than surface irrigation and sprinkler irrigation.
Given that water scarcity in agriculture is a major concern in many places around the world, you can understand why people choose drip irrigation. Worldwide agriculture withdraws 70% of global freshwater for its production. By 2050, we will need to increase our current agricultural production by 70%, if we want to meet the food needs of the global population. Therefore, water usage in agriculture becomes extremely important.
So, how does drip irrigation conserve water usage? Drip irrigation system consists of water delivery pipes that vary in diameters. Different channels and subchannels are created according to the chosen pipe diameter. The pipe diameter is selected based on water pressure and crop type. These pipes are made from plastic-type HDPE (high-density polyethylene), which are non-biodegradable petroleum-based plastic. It has one pump that creates pressure to deliver the water at the required place. However, even though drip irrigation is a great tool for agriculture and water conservation, it has a few weaknesses.
Leaks in Conventional Drip Irrigation Systems
A major hindrance to drip irrigation has been its cost. However, there is another hidden cost, which is plastic pollution. The fertilizers used in agriculture damages the polyethylene layer of the drip irrigation pipes. Moreover, these drip irrigation pipes are left in the soil after it has been damaged. These plastics pipes can remain in the soil for centuries and can harm the soil composition. Adding on to this, many farmers around the world are forced to buy low-cost polyethylene pipes to save money due to their financial circumstances.
The good news is that there is a solution for this plastic problem in drip irrigation systems and that is the bio-degradable drip system. These are being discovered as I write this. However, are they efficient and cost-effective? Let us have a look.
Is the Hype Around Biodegradable Irrigation Systems Real?
Biodegradable plastics require specific conditions to decay. It cannot decompose like natural biodegradable material in any condition. Moreover, if they are mixed with normal plastics, they take longer to degrade. Many studies have been conducted to understand biodegradable tubes and these are some of the common concerns raised by these researchers:
- More head loss means the friction loss will also be more in these pipes.
- Making changes to water flow is hard with this type of material.
- Is not durable in harsh environments.
- Easy availability
- It requires more skill to manage such pipes
Adding on the above concerns, another major issue is that these pipes will not necessarily degrade and dissolve in the soil. This may be confusing because of its name “biodegradable pipes”. The confusion arises from the fact that it is often associated with the term Bioplastic. Bioplastic and biodegradable plastic are not similar. Bioplastic is made from biomass sources like sugarcane. Biodegradable plastics are made from the same source as normal plastic, which is petrochemicals. This means, the material used to make the pipes is the same, however, the process used may differ.
We Need More Innovations in Irrigation Systems in General
The silver lining is that researchers are still working hard to make biodegradable plastic more potent and effective at doing its job. This is important because the use of plastic in agriculture has been increasing. It is being increasingly used for –
Micro-irrigation: Drip and Sprinkler irrigation system
Greenhouses: Plastic or nets are used to cover land and crops are grown inside these covers in a controlled environment
Mulching: Row of plastic sheets are placed over the soil and holes are made in these sheets. The crops are placed in these holes. This prevents loss of water moisture from the soil and therefore crops require lesser water.
It is evident that as we try to save water in agriculture, we will increasingly rely on plastic material to do so. This means we risk the chance of polluting our soil with plastic. This plastic residue decreases soil porosity, air circulation and affects microbial activity. In the end, all these effects soil fertility and crop yield. This can become a vicious endless cycle. Therefore, the farmer is presented with a dilemma, use these pipes to conserve water or use the pipes and negatively impact the soil and its surrounding environment.
The good news is that many countries are currently conducting plenty of research on biodegradable plastic to make it more environmentally friendly and cost-effective. If they can succeed in doing so, they can help farmers avoid the previously mentioned farmer‘s dilemma. In the meantime, we can educate farmers on the negative impacts of plastic on soil and show them how to dispose irrigation pipes after it has been damaged.
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