Who Lives in Rice Fields?

 Who Lives in Rice Fields?

The organic experience has experienced a recent boom in India, and the farmers of Ambasamudram taluk of Tirunelveli district are slowly joining the bandwagon. As we explored the region around the ACCC, we passed a vast sea of paddy. Emerald stalks waved gently in the breeze, the tender, newly-seeded paddy a light green and the mature crop ready for harvest blazing almost yellow under the hot sun. Paddy is as integral to the livelihoods in and around Tirunelveli as is the perennial Tamiraparani. 

Organic farming has long been touted as a way to reverse the negative effects of agricultural intensification. Studies have shown that biodiversity is higher in organic paddy fields than in their conventional counterparts. However, in Tirunelveli district, we met with an interesting conundrum - so few farmers were investing time and resources into organic farming that organic fields were surrounded largely by conventional fields. 

 

Regardless, our group decided to investigate the biodiversity in organic and conventional paddy fields, interested in seeing whether even tiny fragmented patches of organic fields could harbour significantly more taxa than surrounding pesticide-ridden fields. We chose eight fields as our study sites - four organic and four conventional. We used a pairwise site selection technique where two of our organic sites and two of our conventional sites were at the early stage of paddy growth, while the remaining two organic and two conventional sites were at the final (pre-harvest) stage of growth.  

We narrowed our biodiversity of interest down to four larger groups - birds, amphibians, macroinvertebrates, and insects. Our research ended up being highly entertaining, albeit chaotic and involving long hours squatting in soggy paddy fields. We set off at five in the morning, usually in a gaudy auto rickshaw or the trusty Bolero, to the pairs of paddy fields where we would be residing for the day and looked for birds for two hours. Then, we collected macroinvertebrates by scooping with a dip net at six random locations in the paddy field and sieving the muddy water to pick out individual macroinvertebrates. Armed with bottles of struggling macroinvertebrates, we would return to the ACCC and begin the painstaking work of sorting and identifying samples with the help of Antony, a nature educator at the ACCC who was our collaborator and provided us with a wealth of information on macroinvertebrates and insects. 

After a short rest, our team once again departed in the evening for the next phase of sampling - four hours of sitting by a moth screen (meant to catch creepy-crawlies and moths at night) and intermittently checking the screen for any visitors. In between checking the screen, we would sample the field for amphibians. This proved highly amusing, and on the first day, we tried catching and examining the amphibians we spotted. It turns out that frogs do not appreciate being caught and after nearly falling into the field numerous times, we decided to do point counts without handling the poor things. 

 

Perhaps unsurprisingly, we did not find significantly more biodiversity across the taxa in organic vs. conventional fields, or differences between the two stages of paddy growth. The only taxa with a good amount of difference was birds, with more avian life in organic than conventional fields in our study area. The organic fields in Tirunelveli are tiny and squished between vast swaths of conventional fields. The water sources between the fields are the same - pesticides and fertilizers can easily be transported into organic fields despite farmers not applying them to their crops. Thus, there are a lot of subtle factors that are potentially dictating the lack of significant difference in biodiversity in organic vs. conventional fields that point to one thing. If organic farming is to benefit biodiversity in Tirunelveli district and provide a habitat that is pesticide free, plots of organic fields need to be much larger and separated physically from conventional fields. Our study served to highlight this need of the hour.