Advantages of Amending Chemical Fertilizer with Plant-Growth-Promoting Rhizobacteria under Alternate Wetting Drying Rice Cultivation

Chesly Kit Kobua,Ying-Tzy Jou,Yu-Min Wang

doi:10.3390/agriculture11070605

Chesly Kit Kobua, Ying-Tzy Jou + Show 1 more

Open Access

https://doi.org/10.3390/agriculture11070605

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Abstract

Chemical fertilizer (CF) is necessary for optimal growth and grain production in rice farming. However, the continuous application of synthetic substances has adverse effects on the natural environment. Amending synthetic fertilizer with plant-growth-promoting rhizobacteria (PGPR) is an alternate option to reduce CF usage. In this study, a field trial was undertaken in southern Taiwan. We aimed to investigate the effects of reducing CF, either partially or completely, with PGPR on the vegetative growth, biomass production, and grain yield of rice plants cultivated under alternate wetting and drying (AWD) cultivation. In addition, we aimed to determine an optimal reduction in CF dose when incorporated with PGPR for application in rice cultivation under AWD. The trial consisted of four treatments, namely, 0% CF + 100% PGPR (FP1), 25% CF + 75% PGPR (FP2) 50% CF + 50% PGPR (FP3), and 100% CF + 0% PGPR (CONT). A randomized complete blocked design (RCBD) with three replicates was used. A reduction in CF by 25–50% with the difference compensated by PGPR significantly (p ≤ 0.05) influenced the crops biomass production. This improved the percentage of filled grains (PFG), and the thousand-grain weight (1000-GW) of treated plants by 4–5%. These improvements in growth and yield components eventually increased the grain yield production by 14%. It is concluded that partial replacement of CF with PGPR could be a viable approach to reduce the use of CF in existing rice cultivation systems. Furthermore, the approach has potential as a sustainable technique for rice cultivation.

Highlights

IntroductionRice (Oryza sativa) is the principal dietary component for more than 50% of the world’s population [1]
Introduction published maps and institutional affilRice (Oryza sativa) is the principal dietary component for more than 50% of the world’s population [1]
This study concludes that combining chemical fertilizer (CF) and plant-growth-promoting rhizobacteria (PGPR) under the AWD cultivation system can significantly and positively influence crop growth, biomass production, and grain yield

Summary

Introduction

Rice (Oryza sativa) is the principal dietary component for more than 50% of the world’s population [1]. Global cereal production is expected to increase by 13% by the year 2027. Rice production is forecasted to increase by 64 metric tons (Mt) to 562 Mt to satisfy the dietary calorie requirements of the population [2]. Conventional rice production has relied heavily on the use of chemical fertilizer (CF) to obtain the desired crop growth and yield output. The expected increase in rice requirement will further increase the need for CF during the cultivation phase for rice crop. This raises concern as plants do not absorb all nutrients supplied by CF. Pollution is known to occur when these elements discharge through leaching, mineralization, or volatilization, a situation that is further amplified through rapid degradation of the soil structure during the intensive rice cropping cycle [3,4,5]

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