The severe overuse of fertilizers by Chinese farmers has brought about grave ecological consequences and economic losses. Why do Chinese farmers overuse fertilizer?
In some developing countries, the deficient use of fertilizers that leads to low productivity has been a concern. According to a study by Duflo, Kremer, Robinson (2012), few farmers in Kenya used fertilizer despite high returns.
However, in China, the reverse is true—unfortunately too much reverse. The overuse of fertilizer N has become widespread. China has become the largest consumer of synthetic fertilizer nitrogen (N) in the world, accounting for 32% of the world’s total consumption. (Chen et al. 2011) Moreover, the return on the last dollar of fertilizer used was only $0.7 (Huang et al. 2008), which indicates that farmers make losses for overusing fertilizers. In addition, the overuse brought about serious economic consequences, such as damage to water quality and aquatic ecosystems and changes in atmospheric composition (Chen et al. 2011). Since the overuse of fertilizers is at the cost of not only the farmers themselves, but also the government, the environment and the health of the people, why do Chinese farmers overuse fertilizer?
Discussion of possible causes
Hypothesis 1. Lack of knowledge: farmers simply do not know they are overusing. Farmers generally receive very limited education and highly inadequate institutional support on fertilizer application and essentially make decisions on their own. Due to lack of knowledge on the optimum amount of fertilizer usage and the inability to calculate profits, they tend to maximize production instead of profits, and wrongly overuse fertilizer to secure high production. The training program conducted by Huang et al. (2012) which led to a significant reduction (22%) of inorganic N fertilizer use demonstrated that knowledge does affect the farmers’ behaviour.
Hypothesis 2. The fetter of old conventions. It is shown in the research by Zhen et al. (2005) that old farmers are more likely to use more fertilizer. They relied on their empiric knowledge and were unwilling to accept changes. They don’t realize the context of decision making has changed: the varieties change and the quality of fertilizers changes, yet they still apply fertilizers at a high rate.
Hypothesis 3. Low levels of trust. An interesting phenomenon is that even after the farmers received training program and reduced their fertilizer usage, the amount they used was still higher than the suggested amount by the scientists (Huang et al. 2012). This implies that farmers may have misgiving about the interference and may think they know better about their own land than the scientists and choose to believe in their experience. As the scientists usually have little contact with the farmers and only stay near the fields for a short time for the research work, it is very difficult for them to fully persuade the farmers.
Hypothesis 4. Loss aversion. Smaller farms are more likely to have high fertilizer intensities. (Zhen et al. 2005; Pan 2014) The explanation is that farmers with less farm land may find it more difficult to spread the risks across family plots and thus use fertilizer more intensively to stabilize the crop yields. The farmers cannot afford to lose production by testing reducing usage so they stick to the status quo. They keep the high fertilizer usage as the default option and are reluctant to make effort to find out a better option.
Hypothesis 5. Time and labour constraint. After the reform and opening up in China, more and more farmers engage in non-agricultural businesses. For the farmers who engage in off-farm activities, time available to make the decision becomes less. This could be a cognitive limitation that leads to bad decision on the fertilizer usage. Nevertheless, it could also be a rational choice that has taken into account the opportunity cost of labour. As the opportunity cost of labour rises, the farmers are more likely to use fertilizer in a single application rather than using split applications which give higher nitrogen use efficiency but require more labour (Sun et al. 2012). This also leads to higher usage of fertilizers.
Hypothesis 6. Distortion by government subsidies. The Chinese government provides heavy fertilizer subsidies, which result in overuse from the optimal level. While farmers in Kenya claimed that the lack of money was the biggest challenge for them to use fertilizers, the liquidity constraints play a trivial role in influencing fertilizer use in China due to the low price of fertilizers in China. (Zhou et al. 2010) Clearly, if the prices of fertilizers go up, Chinese farmers will reduce their usage.
Hypothesis 7. Present bias of farmers: the gains for the current year are higher valued than equal gains in the future. This can trigger a vicious cycle: the overuse of fertilizer causes land fertility declines. As there is almost no land fallow in China owing to strong demand for arable lands and limited land resources, the lands need high amount of fertilizer on the next year, which again worsens the land. Apart from that, the government used to place pressure on farmers to increase production to achieve local and national food self-sufficiency targets, and farmers reacted by increasing fertilizer use (Sun et al. 2012). Although there is an optimum production for sustainable development which is lower than the maximum output of a single year, the short-sighted policy and short-sighted behaviour make production exceed the sustainable amount.
The possible causes of fertilizer overuse in China are varied. Policy makers face great challenges regarding providing agricultural extension services to farmers. Policy makers should take into consideration the factors affecting farmers’ decision making and behaviours, and design strategies that react to these factors, so that the existing interventions can be improved.
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