Agriculture Part 1

Hi, welcome back.

Last time I, hopefully, gave you an impression of where this blog would take us as well as a few facts and figures to get us rolling. Today I’d like to introduce my first theme in environmental impacts of an increasing human population…..AGRICULTURE.

Hong Kong has a total area of approximately 1100km² consisting of Hong Kong Island, Kowloon Peninsula and the New Territories (including Lantau Island and over 260 smaller islands). The Hong Kong Government estimate that only a quarter of the total area represents ‘developed’ land and it is within this 275km² that the majority of Hong Kong’s 7.2 million strong population live and work.

A false-colour satellite image of Hong Kong depicting developed (pink) and natural (green) landscapes (Courtesy of Wikipedia, annotated by the author).

Clearly the areas of ‘developed land’ are predominantly highly urbanised or industrialised in order to accommodate the local population. Unfortunately outside of this area Hong Kong’s geography mainly comprises mountainous topography that prevents the development of large scale agricultural activity. It is estimated that at the beginning of 2014 there was only 7km² of active farmland in the whole region! (Hong Kong Government, 2014).

So how do they pick up the slack? They look to the north...CHINA! According to the HK Food and Health Bureau 90% of their fresh food is sourced directly from China.

Currently, and historically, China possesses the world’s largest population with 1.3 Billion people in 2013 (you guessed it: World Bank). However, as of 1998 the country only had 0.1 Hectares of arable land per person - that's less than half the world average at the time (Zhu and Chen, 2002). Given their population and low percentage of arable land how do they produce enough to subsist? Let alone have an excess with which to help out other countries?

Well, a major aspect of the country’s high productivity from a limited area is due to the introduction of Nitrogen based chemical fertilisers (CF-N) (Wikipedia). After the Second World War the application of these fertilisers allowed China’s overall food production to increase by over 450% in 50 years (1950-2000) (Chinese Agriculture Yearbook 1980-1999 cited in Zhu and Chen, 2002). This massive growth was achieved in spite of an overall decrease in the total arable area of the country, predominantly due to increasing levels of construction and industrialisation (People's Republic of China Government website).

There we have it: a clear example of an increasing population placing a severe impact on an environment. Complete with an anthropogenic solution of chemically altering the environment in order to inflate its naturally sustainable production level.

However, there are a couple of sides to this story that we have not yet covered: Firstly is the fact that achieving this immense output is requiring higher and higher applications of CF-N's each year. For a little context (by now I hope you realise that this means ‘here are some numbers’) these yearly increases mean that in 1998 China used 30% of the total Nitrogen fertilisers used in the world (Zhu and Chen, 2002).

Ok, that seems like a good place for a cliff-hanger. I’ll get another post up over the next few days where we can further this analysis and have a look at the impact that this massively increased quantity of Nitrogen is having on the natural environment and what steps could/can be taken to mitigate its effects.  Much like Stallone’s chef d'œuvre it’s sure to be a post filled with thrills.