Climate-smart agriculture practices influence weed density and diversity in cereal-based agri-food systems of western Indo-Gangetic plains

Hanuman S Jat,Virender Kumar,Mangi L Jat,Ashim Datta,Parbodh C Sharma,Mahesh K Gathala,Andrew J Mcdonald,Suresh K Kakraliya,Ahmed M Abdallah,Madhu Choudhary

doi:10.1038/s41598-021-95445-1

Abstract

Climate-smart agriculture (CSA)-based management practices are getting popular across South-Asia as an alternative to the conventional system for particular weed suppression, resources conservation and environmental quality. An 8-year study (2012–2013 to 2019–2020) was conducted to understand the shift in weed density and diversity under different CSA-based management practices called scenarios (Sc). These Sc involved: Sc1, conventional tillage (CT)-based rice–wheat system with flood irrigation (farmers’ practice); Sc2, CT-rice, zero tillage (ZT)-wheat–mungbean with flood irrigation (partial CA-based); Sc3, ZT rice–wheat–mungbean with flood irrigation (partial CSA-based rice); Sc4, ZT maize–wheat–mungbean with flood irrigation (partial CSA-based maize); Sc5, ZT rice–wheat–mungbean with subsurface drip irrigation (full CSA-based rice); and Sc6, ZT maize–wheat–mungbean with subsurface drip irrigation (full CSA-based maize). The most abundant weed species were P. minor > A. arvensis > M. indicus > C. album and were favored by farmers’ practice. However, CSA-based management practices suppressed these species and favored S. nigrum and R. dentatus and the effect of CSAPs was more evident in the long-term. Maximum total weed density was observed for Sc1, while minimum value was recorded under full CSA-based maize systems, where seven weed-species vanished, and P. minor density declined to 0.33 instead of 25.93 plant m−2 after 8-years of continuous cultivation. Full CSA-based maize–wheat system could be a promising alternative for the conveniently managed rice–wheat system in weed suppression in north-west India.

Highlights

Rice (Oryza sativa L.)—wheat (Triticum aestivum L.) (RW) is the major agri-food system occupying an area of 13.5 Mha in the Indo-Gangetic Plains (IGP) of South Asia; of which ten Mha in India, with almost 50% (5 Mha) are in western IGP comprising of Punjab, Haryana and western Uttar Pradesh, the food basket of I ndia[1,2]
Under farmer’s practice (Sc1), all weed species almost exhibited the same density across years except for A. arvensis, M. indicus and C. album in which their density was reduced over time (Fig. 2)
(in 2012–2013), maximum weed biomass was observed for P. minor followed by A. arvensis, M. indicus, R. dentatus and C. didymus

Summary

Introduction

Rice (Oryza sativa L.)—wheat (Triticum aestivum L.) (RW) is the major agri-food system occupying an area of 13.5 Mha in the Indo-Gangetic Plains (IGP) of South Asia; of which ten Mha in India, with almost 50% (5 Mha) are in western IGP comprising of Punjab, Haryana and western Uttar Pradesh, the food basket of I ndia[1,2]. Continued cultivation of the same cropping system (i.e. rice–wheat system) over the last five decades allowed certain weed species like Phalaris minor to adapt, increase their establishment, seedbank and p rofusion[8]. Such weeds adversely affect resource use efficiency (light, water and nutrients), and crop productivity[3,9]. We hypothesized that CSA management scenarios (layering of different indicators/practices) could reduce weed density and composition, and diversity indices with no negative impact on wheat performance under rice/maize-based systems

Methods

Results

Discussion

Conclusion