Assessment of recycled treated wastewater for sustainable tomato crop production: A comprehensive review

Abstract

The availability of water is decreasing, especially in areas where natural water supplies are severely depleted. Of the water uses, agricultural water use accounts are the highest. The reclaimed water or treated wastewater provides nutrients to the crop. It reduces fertilizer application rates therefore gives economic benefits to the farmers. However, the use of reclaimed water for crops is still not well understood, and in some regions not readily accepted due to lack of information on the methods and impacts. Therefore, there is a need to conduct a detailed literature review on the use of reclaimed water for crops from case studies. This paper aims to provide a review of the impacts of treated wastewater on soil properties and tomato based on various parameters. This review also helps to decide physical, chemical, and biological parameters to be tested for soil and fruit while researching the reuse of treated wastewater for agriculture. From the review, it can be concluded that by using treated wastewater as an irrigation source for tomatoes, in most cases, soil fertility increases but the porosity and permeability of soil decreases. In the case of treated wastewater, the crop yield is improved by 21 to 59 %, but there was no significant impact on fruit quality. There was no change observed in the size of fruits but microbial contamination was increased in many cases. This review also concludes that the Heavy Metal Concentration Factor (HMCF) changes with a variety of tomatoes but there is not much variation for the same type of tomato variety when irrigated with wastewater having different quality. Overall, the review suggests that wastewater should be treated, tested and then can be reused for the tomato crop in regions with less water availability.