A balance among irrigation and fertilization regimes to reduce greenhouse gases emissions from saline and alkaline soils

Abstract

Agricultural practices of nitrogen and irrigation overuse bring lots of environmental problems, such as greenhouse gases (GHGs) emissions, soil, and water pollution. With the fast expansion of saline and alkaline agricultural soils in the Tarim River Basin, field practice must be very cautious facing water limitations and global warming. The GHGs were measured 1–2 times weekly and water and fertilizer use efficiency were evaluated under five treatments: (1) fallow (Control); (2) no N (kg N ha−1) and no irrigation (mm) (0N0W); (3) 200 and 355 (LNLW); (4) 230 and 475 (MNMW), and (5) 320 and 655 (HNHW) (traditional treatment) from 2018 to 2019 under maize in Aksu in the Tarim River Basin. The GHGs increased with fertilization and irrigation. The cumulative GHGs were 0.6–5.9 Mg CO2–C ha−1, 0.2–3.6 kg N2O–N ha−1, and increased significantly with biomass increase. The cumulative CH4 was −0.03 to −0.12 kg C ha−1. The MNMW resulted in the highest average water use efficiency (27 kg ha−1 mm−1), irrigation water use efficiency (32 kg ha−1 mm−1), and agronomic N use efficiency (44 kg kg−1), but the lowest greenhouse gas intensity (0.4 kg CO2‐eq ha−1 grain yield). The MNMW reduced the average of 10 mm water, 5 kg N ha−1 fertilizer, and 4 × 10−3 kg CO2‐eq ha−1 GHGI earning 1 t ha−1 maize compared to HNHW. The CO2 emission had a strong relationship with temperature (T) and soil moisture (W) (CO2 emission = (exp (a + bW + cW2)) Q10(T‐20)/10)) (R2 = 0.59–0.92). The lowest was in the LNLW treatment in 2019; the highest was in the HNHW in 2018). The emission of CO2 responding to fertilization was below the global trend, but that of N2O was above under maize in saline and alkaline soils (pH 7–9). In conclusion, MNMW was the best field management to mitigate GHGs with the highest water and fertilizer use efficiency under maize in saline and alkaline soils in Tarim River Basin, where had the higher N2O emission risk.

Optimized fertilization mitigated carbon and nitrogen losses in a Solonchak

“…Lyu et al (2021) found that optimized fertilization reduced 49% N 2 O emissions in maize fields in the Hexi Corridor compared with conventional fertilization for 5 years. We also observed a significant positive correlation between N 2 O emissions and WFPS in the present study, which is in agreement with findings from previous studies (Kamran et al, 2023;Li, Ma, et al, 2021;Zhang et al, 2023). Plants also have an important impact on the production and emission of soil N 2 O, which can be mainly divided into two ways: the first way is that plant growth affects the physical and chemical properties, water content and aeration of the soil, thus affecting the diffusion of microbial activity, gas and nutrients in the soil; the second influence pathway is that plants transfer the N 2 O produced in soil through their own aerenchyma, or absorb the watersoluble N 2 O in soil into plants, and then exhaust the gas from plants into the atmosphere through transpiration (Hu et al, 2021).…”

“…Emissions of CO 2 had a significant relationship with the soil properties (soil temperature, WFPS and NH 4 + -N) under different fertilization treatment (CO 2 , y = me nT (a + b WFPS +c WFPS 2 ) + f NH 4 + -N + g, R 2 > 0.52; Figure 7). Soil The N fertilization significantly increased cumulative CO 2 emissions (37-176 kg C ha À1 ; Figure 3a,d), and the results are consistent with the results of cumulative CO 2 emissions from maize fields at seedling growth in the range of 21-196 kg C ha À1 under different fertilization input amounts (0-320 kg N ha À1 ; Zhang et al, 2023). The CO 2 fluxes are positively related to soil moisture (p < 0.05) and temperature (p < 0.05; Figure 7), which is probably due to the activity of heterotrophic microorganisms in the soil (Chu et al, 2023).…”

“…The experiment was conducted from June to August 2019 at the Aksu National Experimental Station of Oasis Farmland Ecosystems (40 37 0 N, 80 45 0 E, altitude 1028 m) in Xinjiang, Northwest China. It has a typical temperate arid climate, with mean minimum and maximum temperatures during the study period (April-November) ranging between 16.6 and 34.8 C. Over the past 30 years (1986 $ 2015), the site's mean annual rainfall was 63 mm, the annual mean temperature was 11.6 C and the frost-free period was 207 days (Huang et al, 2023;Zhang et al, 2023;Zhao et al, 2020). The average air temperature was 25.2 C, with a range of 20.2-29.3 C and soil temperature varied from 26.3 to 32.1 C (Figure 2a).…”

“…The global average temperature is predicted to increase by 2 C by the end of the 21st century (IPCC, 2014), which could be attributed to atmospheric GHG emissions (Cuello et al, 2015;Tian et al, 2016). In the saline-alkaline soils of the Tarim River Basin, Zhang et al (2023) found that N fertilization acts as a substrate for nitrification and denitrification processes, causing a higher risk of N 2 O emissions. China has consumed one-third of the world's N fertilizer in crop production, and nitrogen use efficiency (NUE) is only 20%-25% in saline-alkaline soils (Cui et al, 2018).…”

“…China has consumed one-third of the world's N fertilizer in crop production, and nitrogen use efficiency (NUE) is only 20%-25% in saline-alkaline soils (Cui et al, 2018). Excessive N fertilizer has failed to increase yield and led to considerable N waste and low NUEs (Zheng et al, 2016), leading to nitrate (NO 3 À -N) pollution in groundwater and surface water environments (Guo et al, 2010;Ju et al, 2009;Liu et al, 2020Liu et al, , 2022, soil acidification (Raza et al, 2020), GHG emissions increase (Shakoor et al, 2021;Yu et al, 2021;Zhang et al, 2016Zhang et al, , 2023 and threatens human health (Zhou et al, 2016). N fertilization enriches soil NH 4 + -N and NO 3 À -N pools, subject to enhanced nitrification and denitrification (Kamran et al, 2023).…”