Achieving nutritional goals through conservation agriculture by improving wheat protein content and related efficiencies

Food insecurity and undernourishment pose significant challenges to achieving Sustainable Development Goals (SDGs). Wheat is a major contributor to both food and protein intake globally and is required to be produced in larger quantities in future. Strategic agronomic practices in cereal crops are required to enhance wheat productivity without compromising nutritional composition. This study investigated the impact of conservation agriculture (CA)-based management systems on wheat yield, protein content and related efficiencies in a decade-long experiment. Six management systems (Ms) were evaluated, Ms I- conventional-till (CT) rice–wheat without residue (CT–RW WR ); Ms II- CT rice–zero tillage (ZT) wheat–ZT mungbean with residue retention (CTR–ZTWMb RR ); Ms III- ZT rice–wheat–mungbean (ZT-RWMb RR ); Ms IV- ZT maize–wheat–mungbean (ZT-MWMb RR ); Ms V- Ms III + subsurface drip irrigation (SDI) and Ms VI- Ms IV + SDI. Management systems Ms I-IV were evaluated over five cropping seasons, whereas Ms V and Ms VI were assessed over three cropping seasons. Results showed that the grain protein content in wheat improved significantly with CA-based management systems and was found significantly higher under Ms V and Ms VI where precise nitrogen (N) and water were applied through SDI over Ms I (farmers' practice). On average basis, after 3 seasons of establishment, the CA + SDI systems (Ms V & VI) improved the grain protein content by 11.8 and 12.3% compared to Ms I, respectively. Furthermore, the protein water productivity (PWP) was 117 and 144% higher under SDI irrigated systems (Ms V & Ms VI) compared to Ms I (0.16 kg protein m −3 irrigation water used). The average improvement in protein nitrogen productivity (PNP) of wheat under CA + SDI systems (Ms V & VI) was 69.4 and 75.9% over Ms I (3.36 kg protein kg −1 N applied). The average wheat grain yield was also higher by 23 and 37.2% with Ms V and Ms VI compared to Ms I (5.27 Mg ha −1 ). Moreover, when compared to their respective flood systems (Ms III & Ms IV), the precise N and water application (Ms V & Ms VI) led to additional improvements of 4.9 and 2.1% in protein content, 75.0 and 95% in PWP, and 31.7 and 32.2% in PNP, respectively. Our study underscores the benefits of CA-based cereal systems with precise nitrogen and water management, crucial for addressing food insecurity and advancing global development goals.