Q: How does agriculture place a strain on ecosystems?
A: It really depends of the amount of land dedicated to agriculture. It’s all about balance; if the majority of land in an ecosystem is changed over to an agricultural production system, then the ecosystem will loose balance. Water and nutrient cycling will change and water quality may change, food webs will be altered, habitats will change and the species mix will change.
This leads to problems such as:
> reduction in water quality
> reduction in the amount of water available to an ecosystem, e.g. river system/riparian system
> periodic flooding as a result of reduced water uptake capacity of the agricultural zone; instability of river banks due to the loss of deep roots. These factors can lead to the silting of river systems.
> the loss of species which we might like to have around
Q: Why is agricultural efficiency important?
A: There more efficient an agricultural system is, the more productive it will be, meaning, essentially, that you get more produce of the same quality for each dollar invested in the system.
This is crucial to solving current and future food shortages. If you need less resources today to produce the same product you produced yesterday, then you can produce more today than you did yesterday and meet any additional demand. You can also reduce the price of your produce and thus make it accessible to more people.
Improving agricultural efficiency is thus at the core of agricultural sustainability.
Q: What is hydroponics?
A: Hydroponics is the growth of plants without soil. This may occur via an inert substrate or just in water. All essential plant nutrients and any additional nutrients important for humans are part of the water solution, which is absorbed by the plant.
Of course this process is no different from plants growing in soil, where water releases the nutrients held in the soil before being absorbed. In the case of hydroponics the nutrients have already been added to the water before it is introduced to the plant.
One downside of substrate-less (water only) hydroponics is that it is more energy intensive than hydroponics utilising an inert substrate, as constant pumping action is required in order to aerate the liquid solution.
Q: How water efficient is hydroponics?
A: Traditional hydroponics uses about 70% less water than field agriculture on average. This is because hydroponics generally utilises semi closed loop systems; i.e. water is cycled and recycled. In so far as evaporation can be minimised, water loss can be further reduced. Thus the more compact and efficient the system is, the less water it will use, increasing the length between new water inputs being required.
The less irrigation water is required for crops, the more water will be available for all other functions in the ecosystem. There is a fundamental correlation between water availability/distribution and ecosystem health.
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