High yield of protein-rich forage rice achieved by soil amendment with composted sewage sludge and topdressing with treated wastewater

Luc Duc Phung,Megumi Ichikawa,Toru Watanabe,Atsushi Sasaki,Dung Viet Pham

doi:10.1038/s41598-020-67233-w

Luc Duc Phung, Megumi Ichikawa + Show 3 more

Open Access

https://doi.org/10.1038/s41598-020-67233-w

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Journal: Scientific Reports	Publication Date: Jun 23, 2020
Citations: 10	License type: open-access

Affiliation: Iwate University, Yamagata University

Abstract

Aiming to promote low-cost production of protein-rich forage rice and resource recycling from wastewater treatment plants, a pot experiment was conducted to assess the possibility to substitute mineral fertilizers with composted sewage sludge (CSS) with/without top-dressing with treated municipal wastewater (TWW). Results indicated that a basal application of CSS at 2.6 g N pot−1 replaced conventional mineral fertilization of 1.3 g N pot−1 to produce comparable yields with the same rice protein content, although there might be a risk of increased As concentration in rice grains. Interestingly, CSS application at a reasonable dose of 1.3 g N pot−1, followed by a topdressing with TWW resulted in 27% higher yield and 25% superior rice protein content relative to the mineral fertilization, with no risk of heavy metal(loid) accumulation in grains and in paddy soils. Here we demonstrated an appealing fertilization practice with zero use of mineral fertilizers in paddy rice cultivation, expectedly contributing towards sustainable rice farming and animal husbandry in Japan.

Highlights

Aiming to promote low-cost production of protein-rich forage rice and resource recycling from wastewater treatment plants, a pot experiment was conducted to assess the possibility to substitute mineral fertilizers with composted sewage sludge (CSS) with/without top-dressing with treated municipal wastewater (TWW)
Rice farming demands large quantities of irrigation water and mineral fertilizers, which allows the great opportunity for recycling plant nutrients and water from wastewater treatment plants (WWTPs) to reduce the dependence of the crop production on mineral fertilizers and other freshwater sources through soil amendment with sewage sludge and reuse of TWW
These TWW irrigation systems have proved highly beneficial and applicable to paddy fields located near local WWTPs, from which the effluent is supplied to paddy fields[3]; they frequently face difficulties to attain an even distribution of TWW to paddy fields far from the WWTPs due to the rising cost of instalment of water-distributing pipes/channels

Summary

Introduction

Aiming to promote low-cost production of protein-rich forage rice and resource recycling from wastewater treatment plants, a pot experiment was conducted to assess the possibility to substitute mineral fertilizers with composted sewage sludge (CSS) with/without top-dressing with treated municipal wastewater (TWW). In attempts to promote low-cost forage rice cultivation while recycling plant nutrients and water from WWTPs, we have developed new irrigation systems for effective reuse of TWW as a sole source of both water and plant nutrients to produce high grain yields of protein-rich rice without the need for mineral fertilizers[3,4,5]. These TWW irrigation systems have proved highly beneficial and applicable to paddy fields located near local WWTPs, from which the effluent is supplied to paddy fields[3]; they frequently face difficulties to attain an even distribution of TWW to paddy fields far from the WWTPs due to the rising cost of instalment of water-distributing pipes/channels. Here, we evaluated effects of such management practices on rice growth and development, rice yield and nutrition quality, soil fertility, and accumulation of heavy metal(loid)s in rice grains and in paddy soils

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