Wastewater irrigation in Hubli–Dharwad, Karnataka, enables farmers to diversify their cropping practices - A paper in the Environment and Urbanisation Journal

This paper 'Wastewater irrigation in Hubli–Dharwad, India: Implications for health and livelihoods' is divided into the following sections:

Introduction

The area where the study was conducted, its rainfall pattern, climate, the physical characteristics, soil conditions and location of water courses are presented in this section.

Methodology

Surveys were conducted at intervals between 1997 and 2001, and in 2001, fieldwork was expanded to a transect-based study.

Wastewater-irrigated agriculture

• Main cropping patterns : The 3 distinct cropping systems of vegetable production, field crops with vegetables, and agroforestry along with their spatial distribution is detailed here.
• Irrigation methods :The method used consists of an overland flow and furrow irrigation system using a centrifugal pump along with some form of filtration.
• Wastewater properties : Research showed that for many plant nutrient ions, concentrations in wastewater was similar to those from borehole water, with the exception of total suspended solids (TSS) and its associated biological oxygen demand (BOD ). Presence of heavy metals was below the permissible limits.
• Vegetable production: A distinct feature of this system is the year-round production of vegetables for sale and the absence of a fallow period, requiring considerably higher labour input, as there is a problematic increase in the incidence of weeds and pests.
• Field crops with vegetables: Larger farms have more land devoted to field crops, as vegetable production requires greater labour inputs. Nature of the cropping patterns changed at increased distance from Dharwad.
• Agroforestry: In the peri-urban villages all farmers bordering the nalla engaged in wastewater-irrigated agroforestry.
• Fodder production: A dairy farmer irrigated land for fodder production, alternating wastewater with borehole water on a daily basis, producing an impressive two-fold increase in milk yield.

Discussion

Health issues: Some of the major concerns are

• Wastewater laden with faecal bacteria exposes the farmer to the risk of dysentery or cholera
• Due to nutritional deficiency and worm infestation anaemia was common
• Crop samples taken from a ridge were bacterially contaminated by the wastewater flowing in the furrow
• Due to intensive use of pesticides, cumulative effect of organophosphate pesticide poisoning rises
• Farmers have reported presence of disposable needles and syringes in the wastewater

Gender implications of wastewater irrigation

• Due to the high nutrient loading from wastewater, there is great increase in the incidence of weeds leading to higher labour inputs
• Higher percentage of women labourers are hired due to cheaper rates
• Working full day in the fields increases women’s exposure to the hazards of wastewater
• Food preparation and cooking by these women, increases the risk of pathogen transfer to other family members

Management of irrigation with wastewater

• Outright banning of wastewater irrigation would be neither practical nor feasible
•  The economic implications of such a measure too would be vast and affect the farmers in this area

Conclusion

For public health and environmental risks to be mitigated without threatening the livelihoods of poor farmers the following steps may be undertaken:

• Involving non-governmental organizations in mobilizing the farming community into self-help groups to facilitate learning in sustainable agricultural practices
• A village-based extension approach to suit safer and more sustainable farming practices
• Public health benefits could be enhanced through public education aimed at raising awareness of disease prevention