Effects of Water-Saving Irrigation on Direct-Seeding Rice Yield and Greenhouse Gas Emissions in North China

Abstract

Rice cultivation consumes more than half of the planet’s 70% freshwater supply used in agricultural production. Competing water uses and climate change globally are putting more pressure on the limited water resources. Therefore, water-saving irrigation (WSI) is recommended for rice production in water scares areas. The impact of WSI techniques on direct-seeding rice production and greenhouse gas emissions in North China is becoming increasingly important in the era of climate change. Therefore, we conducted a two-year field experiment on directly seeded rice to assess the impact of traditional flooding irrigation (CK) and three water saving irrigation (WSI) methods, including drip irrigation with an irrigation amount of 50 mm (DI1) and 35 mm (DI2) at each watering time and furrow wetting irrigation (FWI), on rice yield and greenhouse emissions. Generally, the WSI techniques decreased the number of rice panicles per m−2, spikelet per panicle, 1000-grain weight and rice yield compared to CK. Rice yield and yield components of (DI1) were significantly higher than (DI2). The adoption of either (DI1) or (FWI) showed insignificant variation in terms of rice yield and its yield components measured except for 1000-grain weight. The water productivity was 88.9, 16.4 and 11.4% higher in the FWI plot than the CK, DI1 and DI2 plots, respectively. The WSI decreased cumulative CH4 emission significantly by 73.0, 84.7 and 64.4% in DI1, DI2 and FWI, respectively, in comparison with CK. The usage of DI2 triggered 1.4 and 2.0-fold more cumulative N2O emission compared to DI1 and FWI, respectively. Area-scaled emission among the water-saving irrigation methods showed no significance. The yield-scaled emission in DI1 and DI2 and FWI were 101, 67.5 and 102%, respectively, significantly lower than CK. The adoption of FWI produced an acceptable rice yield with the lowest yield-scaled emission and highest water productivity among the irrigation practices. Our experiment demonstrates that dry direct-seeding with furrow irrigation can impact triple-wins of sustainable rice yield, high water-use efficiency and low GHG emissions in North China.

Soil Nitrogen Distribution Affects Nitrogen Utilization and Yield of Drip-Irrigated Rice

“…Specifically, compared with traditional flooded rice production, drip irrigation can save 65% of water and increase fertilizer utilization by 10% [8,9]. However, the yield of drip-irrigated rice (5.9-8.7 t•ha −1 ) has fallen far below the expected target (10.9-12.05 t•ha −1 ) recently [10]. The reason for this discrepancy is the occurrence of rice spikelet degeneration in drip-irrigated rice [11], yet the mechanism behind this phenomenon has not been well explained.…”

Eco-hydrological modeling of soil wetting pattern dimensions under drip irrigation systems

“…This approach is one of the most effective methods to deliver water and nutrients to the root zone of plants [ 4 , 5 ]. The water savings recorded compared to other surface irrigation methods could be as high as 50% for a drip irrigation system [ 6 ].…”

Increasing the yield of drip-irrigated rice by improving photosynthetic performance and enhancing nitrogen metabolism through optimizing water and nitrogen management

“…It has the potential to achieve high rice yield (12.1 t•hm -2 ), water savings (65%), fertilizer savings (20%) and cost savings (17.2% cost reduction) (Chen et al, 2013). In the actual production of rice in arid areas, dripirrigated rice significantly improves WUE (1.08-1.13 kg•m -3 ) (Hang et al, 2022), but the grain yield (5.9-8.7 t•hm -2 ) is much lower than the expected target (10.9-12.05 t•hm -2 ) (Chen et al, 2013;Hang et al, 2022). Meseret et al (2022) concluded that split applications of nitrogen fertilizer according to the demand of the crops and at the key growth stages of crops have an important effect on crop growth and yield.…”