In my previous blog post, I covered how pesticides are incredibly dangerous not only to us but also to the environment. This post is a follow-up to the previous post, and I would be exploring some popular nature-based alternatives to see if these options could be the answer towards stopping such environmental pollution.

Potential option 1: Using fewer pesticides

Research on trying to reduce pesticide usage for agricultural purposes has shown that in conventional modern agricultural fields, it was recommended that using fewer pesticides than currently used was highly beneficial for crop yield. Webster et al.’s experiments showed that a combination of initial pesticide usage, coupled with additional farming processes involving mechanical weeding, crop walking and soil sampling to identify the pests and problems that require intervention allowed for comparable crop margin yields to existing practices (Webster, Bowles and Williams, Estimating the economic benefits of alternative pesticide usage scenarios: wheat production in the United Kingdom 1999). Their experiments showed that using no pesticides at all resulted in lower yields as compared to using pesticides.

Figure 1: Comparison of crop yields between conventional pesticide usage (CP94), Integrated Farming Systems (IFS) and No Pesticides (NP) Source: (Webster and Bowles  1997)

 

Potential option 2: Trying an alternative nature-based pesticide

From the earlier example, some levels of pesticides are still required for yields to be sustained. What if we try a different approach from conventional farming techniques? One such method would be to use agroforestry practices. This involves substituting chemical pesticides with known natural predators for pests. One research found that such agroforestry practices were effective in significantly reducing pests, weeds and crop damage for perennial crops (crops that fruit throughout the year) (Pumarino, et al. 2015).

The idea of using no chemical pesticides appears as a wonderful solution to solving this environmental crisis, yet, this solution is surprisingly more problematic to the local ecosystem. To introduce these pest enemies, we are essentially introducing alien species to curb the problem. This introduction of exotic species is potentially decimating for the local ecosystem since there usually are no existing predators to control these introduced predators. If poorly studied and introduced into the ecosystem, it could be an invasive species and harm the native biodiversity.

The problem is complex since different species interact differently with each other; some introduced species are symbiotic, while others become invasive (Rao, Singh and Day 2000). The issue is further complicated by other environmental factors, such as microclimate (Rao, Singh and Day 2000). These effects and interactions remain poorly understood to date.

A major hurdle to overcome is the relative lack of research on the specific impacts a species can do on a different ecosystem; much of the existing literature writes about requiring further research since “very little has been published” (Richardson, Binggeli and Schroth 2004). Perhaps, this is something that we should focus more on since agroforestry is promising if done right, and we still have a long way to go before getting it right.

 

References

Pumarino, Lorena, Gudeta Weldesemayat Sileshi, Sofia Gripenberg, Riikka Kaartinen, Barrios Edmundo, Mary Nyawira Muchane, Charles Midega, and Mattias Jonsson. 2015. “Effects of agroforestry on pest, disease and weed control: A meta-analysis.” Basic and Applied Ecology 16: 573 – 582. doi:https://doi.org/10.1016/j.baae.2015.08.006.

Rao, M. R., M. P. Singh, and R. Day. 2000. “Insect pest problems in tropical agroforestry systems: Contributory factors and strategies for management.” Agroforestry Systems (Kluwer Academic Publishers) 50: 243 – 277. doi:https://doi-org.libproxy1.nus.edu.sg/10.1023/A:1006421701772.

Richardson, David M., Pierre Binggeli, and Götz Schroth. 2004. “Invasive Agroforestry Trees: Problems and Solutions Chapter 15.” In Agroforestry and biodiversity conservation in tropical landscapes, edited by Götz Schroth, Gustavo A. B. Fonseca, Celia A. Harvey, Claude Gascon, heraldo L. Vasconcelos and Annie-Marie N. Izac, 371 – 396. Island Press. https://library.uniteddiversity.coop/Permaculture/Agroforestry/Agroforestry_and_Biodiversity_Conservation_in_Tropical_Landscapes.pdf.

Webster, J.P.G., and R.G. Bowles. 1997. “The costs and benefits of pesticides: wheat and apples in the United Kingdom.” FBU Occasional Paper (United Kingdom) 26: 115. ISBN: 0-86266-169-2.

Webster, J.P.G., R.G. Bowles, and N.T. Williams. 1999. “Estimating the economic benefits of alternative pesticide usage scenarios: wheat production in the United Kingdom.” Crop Protection (Elsevier) 18: 83 – 89. doi:https://doi-org.libproxy1.nus.edu.sg/10.1016/S0261-2194(98)00085-4.