Bigger the family, more the mouths to feed.
When the human family is as large as 7 billion, the amount of food that needs to be produced to feed all of them (ideally) is mind boggling. In India, the amount of calories that a healthy male is expected to eat is about 3100 calories per day, and a healthy female is expected to eat about 2500 calories everyday. This basically means
the equivalent of two large meals of chapathi (flatbread), rice, dals, curries and a portion each of vegetables and fruits.
The practice of feeding a lot of mouths: Modern agriculture
Agriculture has been practiced in human society for the last 10,000 years. But for most part, human popuation stayed under 1 billion. Today, in order to ensure enough food is produced, farmers have had to resort to “modernized” agricultural practices. What does that include?
- Use of sophisticated irrigation techniques.
- Use of chemicals in the form of fertilizers and pesticides.
- Use of enhanced variety of seeds and crops.
- Use of hybrid crops.
- Use of chemicals to enhance the crop properties; smell, size, time for maturity, etc.
All of these enhancement are to produce crops that are bigger, grow faster, and are resistant to environmental stresses. The practices have ensured that we can get more, much more, out of a given piece of land; more yield in less time.
Is that a good thing?
While these practices have ensured short term super-production of food (see the impact of Green Revolution on food production), the environmental effects have been largely adverse.
Land degradation: Role of agricultural practices
Most of these practices are not tuned with the natural processes and the natural variety found in nature. That is why, they have been causing land degradation (among other things).
The intensive irrigation done by farmers on a single patch of soil has caused a lot of the soil to be compressed and/or washed off. Imagine, a patch of rice field that needs to be submerged under water for almost 60% of the rice production time. Now, multiply that into the number of crops the farmer is forced to harvest every year (about 3 crops). In a year, the land is under water for 7-8 months. That’s almost like a wetland! As this water infiltrates the soil, it would leach a lot of the nutrients deep into the ground. The soil pores would become compact and/or filled with water. Organisms living there would be drowned. Soils have got higher salinity and alkalinity than before. And when this water is drained out, it washes away much valuable soil with it.
The increased use of chemicals; as fertilizer and pesticide, has disturbed the natural balance of nutrients in the soil. Today, most farmers overuse these products. What’s worse is that they overuse some of these products. If a farmer overused the NPK fertilizer, the nitrogen, phosphorous and potassium content of the soil drastically increases. While this may help the immediate crops grow, most plants cannot survive in extreme conditions. In the long-term, increasing nitrogen, phosphorous and potassium in the soil increases the acidity of the soil, which reduces the uptake of these nutrients. As a result, there is no increasing benefit from adding fertilizers after a critical threshold is reached. Research shows that we can get the same yield with 40% less fertilizers currently being applied to fields. The excess amount of macronutrients, particularly nitrogen and phosphorous, get washed away with irrigated water to local water bodies, leading to eutrophication .
Modern agricultural practices have also shifted our agriculture system from a polycrop to a monocrop culture. Few staple and economic crops are grown extensively, other indigenous varieties are shunned. Previously, a single patch of land would have many types of crops being grown in it over the year. This would allow the land to replenish itself of lost nutrients, since different crops have different nutrient requirements. With monocrops, the diversity of an agricultural ecosystem decreases and impacts other microorganisms and insects that could have stabilized the ecosystem.
Further, monocrops with heavy fertilizer application has lead to a spike in pest attacks (larger crops also mean more food for pests!). This is causing increasing use of another agricultural input; pesticides. Pesticides have a destabilizing on the ecosystem by selectively killing parts of a food web. Sometimes, pesticides also kill the insect along with their natural predators. Insects tend to develop mutations to build resistance to pesticides as well. When the natural predators of an insect are dead, the insect population will greatly rise with these mutations, leading to resurgence of pest attacks.
An interesting problem has arisen with increased agricultural potency. Previously wasted lands, highly acidic or alkaline lands have now become potential agricultural land, because our new varieties of crops are resistant to harsh conditions. For example, the development of wheat varieties tolerant to acid soil conditions with high aluminium content, permitted the introduction of agriculture in sensitive Brazilian ecosystems as Cerrado semi-humid tropical savanna. Today, the land there is further depleted in living condition for the native species there, and has resulted in huge biodiversity loss.
Well, the population isn’t growing any smaller. Therefore, we have to continue growing crops intensively and round the clock. One way to minimize pressure on land is to reduce food wastage. Many of the western countries have a food surplus; many of the eastern countries have a food deficit. A lot of the food produced and stored in warehouses are spoiled naturally or infested by pests and destroyed. Such management mistakes can be reduced, and we would not need to produce so much food.
We could also shift from modern to ultra-modern agricultural practices. Sprinklers and drip system could be used instead of inundating land. Multi-cropping; many crops on a single land at the same time is an interesting option. Crop rotation is a practice that is being reintroduced in many areas. Natural variations of fertilizers and pesticides are also to be considered seriously. All of this will allow us to produce the food we need and also present loss of valuable land.
Categories: Environmental degradation