Nitrogen optimization coupled with alternate wetting and drying practice enhances rhizospheric nitrifier and denitrifier abundance and rice productivity

Abstract

Optimizing nitrogen (N) fertilization without sacrificing grain yield is a major concern of rice production system because most of the applied N has been depleted from the soil and creating environmental consequences. Hence, limited information is available about nutrient management (NM) performance at a specific site under alternate wetting and drying (AWD) irrigation compared to conventional permanent flooding (PF). We aimed to inquire about the performance of NM practices compared to the farmer’s fertilizer practice (FFP) under PF and AWD on rhizospheric nitrifier and denitrifier abundance, rice yield, plant growth, and photosynthetic parameters. Two improved NM practices; nutrient management by pig manure (NMPM); 40% chemical N replaced by pig manure (organic N), and nutrient management by organic slow-release fertilizer (NMSR); 40% chemical N replaced by organic slow-release N were compared. The results showed an increased total grain yield (16.06%) during AWD compared to PF. Compared to conventional FFP, NMPM, and NMSR significantly increased the yields by 53.84 and 29.67%, respectively, during AWD. Meanwhile, PF prompted a yield increase of 45.07 and 28.75% for NMPM and NMSR, respectively, (p < 0.05) compared to FFP. Besides, a significant correlation was observed between grain yield and nitrogen content during AWD (R2 = 0.58, p < 0.01), but no significant correlation was observed during PF. The NMPM contributed to photosynthetic attributes and the relative chlorophyll content under both watering events. Moreover, relatively higher abundances of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) were observed during AWD, and the highest value was found after the late panicle stage. Our results suggest that the AWD–NMPM model is the best option to stimulate nitrifier and denitrifier gene abundance and promote rice production.

Interaction between water, crop residue and fertilization management on the source-differentiated nitrogen uptake by rice

“…With respect to CF, the adoption of AWD cycles after tillering was shown to result in a lower plant growth during the early vegetative stages, particularly for root development, in line with previous findings (Suriyagoda et al 2014;Weerarathne et al 2015;Zhou et al 2020;Wu et al 2022). Several authors have however observed a positive plant growth response under AWD, with an increase in root length and dry matter accumulation (Kato and Okami 2010;Thakur et al 2011;Hazra and Chandra 2016;Abid et al 2022). It is well-known that rice plants grown under AWD can regulate the growth of above and belowground biomass in different proportions depending on the stage of the growing cycle (Zhang et al 2021).…”

Effects of Straw Returning and New Fertilizer Substitution on Rice Growth, Yield, and Soil Properties in the Chaohu Lake Region of China

“…Previous research shows that slow-release fertilizers, water-soluble fertilizers, crop straw, and other organic fertilizers are common fertilizer sources to replace chemical fertilizers in crop production, improving the quality of cultivated land while ensuring the quality of agricultural products and the safety of the ecological environment. Abid et al reported that 40% chemical N replaced by pig manure promoted higher rice production, followed in descending order by 40% chemical N replaced by organic slow-release farmer fertilizer practices [20]. In both organic (farmyard manure, cow dung, biogas slurry, sugarcane bagasse) and inorganic (gypsum and lignite) amendments, cow dung significantly improved rice growth and physiological parameters [21].…”