Quick questions on Agriculture, Food Production and Land Use - TCE Environmental Science (Tasmania)

Agriculture is not separate from nature; it is the management of ecosystems to harvest energy and nutrients for human use. Crops depend on healthy soil that holds water and nutrients, on the water cycle to supply rainfall and rivers, on decomposers and nutrient cycling to maintain fertility, and on insects and other animals to pollinate many flowering crops. Aquaculture, the farming of fish and shellfish, depends on clean, oxygen-rich water and on the marine food web. Because food production relies on these services, degrading them undermines future productivity.

Intensive cropping and grazing place heavy demands on soil. Removing vegetation exposes soil to wind and water erosion, stripping the fertile topsoil that took centuries to form. Continuous cultivation can reduce soil organic matter and structure, lowering its ability to hold water and nutrients. Compaction by machinery and livestock reduces the pore space roots and soil organisms need.

Agriculture is the largest user of fresh water in Australia, mostly for irrigation. Diverting water from rivers for crops reduces environmental flows, harming wetlands and aquatic species, as seen in the long-running pressure on the Murray-Darling Basin on the mainland. Fertilisers and animal waste washed off farmland carry nitrogen and phosphorus into waterways, driving eutrophication. Pesticides can poison non-target species and accumulate in food chains.

Sustainable practices aim to keep producing food while protecting ecosystem services. These include rotating crops and using cover crops to maintain soil organic matter, minimum-tillage farming to reduce erosion, matching fertiliser application to crop needs to cut runoff, fencing and revegetating waterways, integrated pest management to reduce chemical use, and careful siting and fallowing of aquaculture leases. Tasmania's relatively cool, wet climate and clean image support premium agriculture, which gives producers a commercial reason to protect environmental quality.