Along with the global climate change, gully erosion, flood and drought jointly restrict the sustainable development of arid rangeland in Central Asia. Rainwater harvesting (RWH) system in gully is a flexible practice that alleviate complex environmental problems. In the Kulusitai watershed of Xinjiang, China, our study presented a decision-making system using GIS combined with multi-criteria analysis and a field survey to identify suitability of gully for RWH. The results showed that nearly 40% of rangeland belonged to high runoff potential area, and gullies as the runoff collection channel became the potential site of RWH. The selection of RWH systems depended on catchment environment and gully characteristics. Therefore, based on the unique natural conditions of Xinjiang and successful RWH cases in other regions, we discussed some suitable low-cost RWH techniques to restore degraded grassland and promote community development. Our study will provide some suggestions for ecological restoration and pasture management in arid regions of Central Asia.

Distribution and storage of soil organic and inorganic carbon under different ecological zones in Xinjiang, China

Soil salinization severely constrains agricultural productivity and ecosystem sustainability. Suaeda salsa L. is a representative halophyte and demonstrates strong adaptability and potential for saline–alkali land restoration. To elucidate its physiological responses to salt stress, pot experiments were conducted under four salinity levels, namely CK (0 mM NaCl), LS (800 mM NaCl), MS (1600 mM NaCl), and HS (2400 mM NaCl), with 20 replicates per treatment, and the dynamics of endogenous hormone were analyzed using targeted metabolomics. The soil salinity levels were prepared by adding NaCl solutions of different molarities to achieve the desired salinity treatments. Results showed that low to moderate salinity (CK-LS: 0–800 mM) promoted growth performance, whereas higher salinity (HS: 2400 mM) significantly inhibited biomass accumulation, plant height, and stem diameter (p < 0.01). Salinity markedly affected nutrient accumulation in Suaeda salsa, with Na increasing up to 222%, K decreasing by 17–33%, Ca by 7–21%, Mg by 35–46%, and S by 45–56% across growth stages, while Fe remained unchanged. Under increasing salinity, stress-related hormones such as abscisic acid, jasmonic acid, salicylic acid, and indole derivatives were upregulated, while gibberellins decreased markedly. Zeatin and its derivatives showed significant increases under MS (p < 0.01). Correlation analysis indicated positive associations of abscisic acid and zeatin with growth traits, and negative correlations for gibberellins (R > 0.6). These findings suggest that Suaeda salsa adapts to saline conditions by modulating hormone-mediated ion balance, osmotic regulation, and defense metabolism, thereby optimizing growth and biomass allocation under salt stress.

Glycyrrhiza uralensis is an important plant in desert ecology, where low rainfall and water scarcity limit its growth. In order to explore harvested rainwater and use for Glycyrrhiza uralensis growth and to reduce water scarcity in Northwest China’s arid area, this study was conducted in April and July of 2023. Five types of slope micro rainwater collection measures, including horizontal terraces, square ridges, and contour ridges, were utilized to monitor rainfall and runoff. Glycyrrhiza uralensis seedlings were utilized as test subjects for supplementary irrigation in pots utilizing the natural drought method. The results show that supplemental irrigation boosts Glycyrrhiza uralensis root growth and water uptake capacity in short-term drought conditions. Irrigation with 42.97 mm enhanced Glycyrrhiza uralensis root length, belowground dry weight, and water use efficiency by 104.5%, 39.54%, and 4.18%. Supplemental irrigation under prolonged drought stress shifted Glycyrrhiza uralensis development from below- to aboveground, resulting in decreased activity of osmotic adjustment material activity in leaves. After 31 days of continuous drought following supplemental irrigation, plant height and aboveground fresh weight increased by 58.16% and 20.03%, respectively, whereas the superoxide dismutase activity was reduced by 63.16% in the 42.97 mm irrigated treatment. Furthermore, under short-term drought stress following supplemental irrigation, leaf water use efficiency was primarily influenced by osmoregulatory substances and plant growth characteristics. Under long-term drought stress, it was influenced by osmoregulatory substances and photosynthetic properties. This research is critical for preventing soil erosion and restoring grassland ecological health in the Ili River Valley.

Urea supplements, such as humic acids, could enhance fertilizer nitrogen use effectiveness. Melting is superior to mixing for humate urea application; however, the effects of diverse humate ureas from various coal sources on soil N supply remain unclear. This study compared the properties of two humic acids from different coal sources (HA1, weathered coal; HA2, lignite coal), and their impact on soil mineral N supply and the nitrate–ammonium ratio under flooded and 60% water-filled pore space (WFPS) over a 14-day incubation. Humate ureas stimulated soil mineral N accumulation and balanced the soil nitrate–ammonium ratio at 1:1; however, no significant difference existed between the two humate ureas under 60% WFPS. Humate urea enhanced soil ammonium nitrogen (NH₄⁺-N) retention and delayed nitrate nitrogen (NH₄⁻-N) release, leading to soil mineral N retention, especially in lignite humic acid urea (H2AU) treatments from lignite under flooding. Structural equation modeling (SEM) and linear regression revealed that humic acids elevated soil redox potential (Eh) and electrical conductivity (EC), stimulating soil N mineralization and adjusting the optimal nitrate–ammonium ratio. Humate urea improved soil mineral N supply compared to traditional urea treatments, and humic acids from lignite were more beneficial for crop cultivation from a mineral soil N supply perspective. These findings enhance our understanding of humate urea benefits and aid in optimizing humic acids application for N management.

In arid regions, yields from safflower plants are appreciably lower than normal. Foliar application of zinc or glycine betaine has been reported to increase yields in other grown crops. A field experiment was conducted to compare the specific effects and mechanisms of foliar-applied zinc or glycine betaine on safflower yield in this study. Seven foliar spraying treatments were implemented, including a control (spraying water), three concentrations of zinc sulfate (Zn1: 0.6 g L⁻¹, Zn2: 0.8 g L⁻¹, Zn3: 1.0 g L⁻¹), and three concentrations of glycine betaine (GB1: 0.23 g L⁻¹, GB2: 0.47 g L⁻¹, GB3: 0.70 g L⁻¹). Results showed that Zn1 treatment had the highest grain yield at 2197 kg ha⁻¹, which was 45.4% higher than the control. GB3 treatment resulted in a grain yield at 2127 kg ha⁻¹, which was 40.8% higher than the control. The yield increase mechanism for the zinc treatment was primarily due to optimized plant morphology and improved photosynthetic performance, while glycine betaine improved yield mainly through antioxidant regulation. This study has important implications for water-saving and sustainable agriculture development in arid regions.