Background: Agricultural irrigation is an important practice to safeguard crops against drought and enhance grain yield in arid regions. The Hexi Corridor, known as a classic arid region, faces significant pressure on agricultural production and food security due to the scarcity of water resources. There is an urgent need to investigate agricultural water use of the irrigated regions. Water use efficiency (WUE), defined as the ratio of gross primary productivity (GPP) to actual evapotranspiration (ET), serves as a valuable indicator linking carbon assimilation and water loss. It enables the quantification of areas where water can be utilized more effectively. However, the long-term spatiotemporal dynamics of WUE and driving mechanism in the irrigated areas of the Hexi Corridor remain unclear. Results: This study used GPP calculated by a light use efficiency model (EF-LUE), ET estimated by an ETMonitor model and irrigated cropland maps across China (IrriMap_CN) to examine the spatiotemporal dynamics of irrigated cropland WUE and its controlling factors in the Hexi Corridor from 2001 to 2018. The results are as following: (1) The average annual WUE was approximately 1.34 ± 0.38 g C kg⁻¹ H₂O yr⁻¹, with an increasing trend of 0.012 g C kg⁻¹ H₂O yr⁻¹, and faster growth observed during 2011–2018 compared to 2001–2010. (2) The contribution of GPP to WUE trends and WUE interannual variability (IAV) was greater than that of ET. (3) The dominant climatic factors of WUE IAV in the Hexi Corridor were SPEI, precipitation, and soil moisture. (4) The standardized Structural Equation Model (SEM), incorporating the relationship between WUE and factors such as water, energy, NDVI, and water-saving irrigation, explained 81% of the variation in irrigated cropland WUE. Here, biological factors (GPP and NDVI) were the primary factors influencing WUE variability, and water-saving irrigation had a stronger indirect effect than climate factors (water and energy) on variation in WUE. Conclusions: Our findings offer valuable theoretical insights into the mechanisms governing the interaction between the carbon and water of irrigated cropland, guiding the management of water resources and land in agricultural practices within the Hexi Corridor.

The objective of this study was to conduct a comparative analysis of the performance of hydrogels prepared from two distinct raw materials and to identify the hydrogels with the optimal overall capacity for dry farming applications. Ten grafted polymer hydrogels were prepared from melon peel (MP) and orange peel (OP). A comparative analysis of the degree of swelling, water absorption time, pH range, reusability, and soil water retention and water-holding capacity of the two hydrogels revealed that the MP-based hydrogels exhibited superior performance in all evaluated parameters when compared to their OP-based counterparts. The treatment group of hydrogels prepared from MPs exhibited the highest degree of swelling, with an absorptive capacity of up to 765.6 g/g in ultrapure water. The optimum absorption ratio at pH = 8.1 was 606.8 g/g, as determined by Gaussian distribution modeling. The treatment group with the best reusability demonstrated an average absorption ratio of 445.0 g/g. The degree of swelling was 84.0 g/g when the process was repeated seven times. After the MP-gels were applied to the soil, it was observed that the gels enhanced the water retention and holding capacity of the sandy soil. The water retention ratio of the sandy soil was increased by 271.0% by the addition of MP-gel, and the growth of wheat was found to be normal when 1.5% to 2.0% of MP-gel was added under drought-stress conditions. In light of the necessity to reuse agricultural waste, the preparation of MP-gel can facilitate the improvement of dry farming and address the issue of water scarcity in agriculture. This offers a viable solution for the growth and management of crops under conditions of drought stress.

Potatoes (Solanum tuberosum) are the most important noncereal crop in the world. Increasing potato production is critical for future global food security. China is the world’s largest potato producer, and potato productivity is constrained by water scarcity and poor fertilizer use efficiency (NUE_F). Recently, autumn film mulched ridge microfurrow rainwater harvesting (ARF) tillage has been successfully applied in potato production in dryland farming in Northwest China. However, the effects of ARF on the use efficiency (NUE_F) of applied nitrogen (N), phosphorus (P), and potassium (K) nutrients in potatoes have not been systematically studied. A 3-year, consecutive field trial with four treatments, including moldboard planting without fertilizer application (control, CK), spring and autumn film mulched ridge microfurrow rainwater harvesting planting (SRF and ARF), and standard film mulched ridge-furrow planting (FRF), was conducted during 2018–2020. ARF greatly increased the water levels in the 0–200 cm soil profile at potato harvest compared to SRF, FRF, and CK. ARF and SRF significantly increased the levels of soil organic carbon (SOC), total and available NPK (TN, TP, TK and AN, AP, AK) compared to FRF and CK, with ARF being the most efficient at increasing the levels of the AN, AP, and AK. ARF significantly improved the soil water and nutrient activity and contributed the most to potato tuber and biomass yield and hence the NUE_F. Under ARF, significant and positive associations were observed between the soil fertility traits, soil water storage (SWS), potato tuber yield, biomass yield, and NUE_F. Soil fertility traits and the SWS were positively correlated with potato tuber and biomass yield. The SWS, potato tuber, and biomass yield positively correlated with the partial factor productivity (PFP) and the recovery efficiency (RE) of the applied NPK nutrients. Increased nutrient levels and their combination increased the NUEF and NUEF’s components. The TN and AN contributed more significantly to the PEP and agronomic efficiency (AE) of the applied NPK nutrients; the TP was significantly positively correlated with the AE (AE_N, AE_P, and AE_K), while the AP was correlated with PEP (PFP_N, PFP_P, and PFP_K) and RE (RE_N, RE_P, and RE_K); the TK was significantly positively correlated with the PFP and RE of the applied PK nutrients, while the AK was significantly positively correlated with the PE_P, AE, and RE of the applied K nutrients. Therefore, ARF results in a synchronous increase in yield and NUE_F and is the most efficient planting system for potato production in dryland farming.

Under the increasing severity of drought issues and the urgent need for the resourceful utilization of agricultural waste, this study aimed to compare the soil water retention properties of hydrogels prepared from Chinese cabbage waste (CW) and banana peel (BP) using grafting techniques with acrylic acid (AA) and acrylamide (AAm). Free radical polymerization was initiated with ammonium persulfate (APS), and N, N′-methylene bisacrylamide (MBA) served as the crosslinking agent to fabricate the grafted polymer hydrogels. The hydrogels were subjected to detailed evaluations of their water absorption, reusability, and water retention capabilities through indoor experiments. The optimal hydrogel was identified and its applicability in wheat seedling growth was assessed. The findings revealed that the CW-gel, with an equilibrium swelling ratio of 551.8 g/g in ultrapure water, demonstrated remarkable performance and sustained a high water retention of 57.6% even after drying, which was markedly superior to that of the BP-gel. The CW-gel with the best comprehensive properties significantly improved water retention in sandy soil by 78.2% and prolonged the retention time by five days, indicating its potential for long-term irrigation management. In contrast, the BP-gel showed better performance in clay soil, with an increased water-holding capacity of 43.3%. The application of a 1.5% CW-gel concentration under drought stress significantly improved wheat seedling growth, highlighting the role of hydrogels in agriculture and providing a new path for sustainable water resource management in dryland farming.

Vegetation restoration is a critical strategy for addressing ecosystem degradation globally. However, understanding the specific impacts of land-use changes, particularly the conversion of farmland to forestland and grassland, on soil nutrients and microbial biomass in the Loess Plateau remains limited and requires further evaluation. Therefore, this study was conducted to explore how these conversions affect soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), and microbial biomass components under various land-use patterns. We studied the SOC, TN, TP, soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), microbial biomass phosphorus (MBP) content and their ratios under six land-use patterns (Farmland (FL), Abandoned cropland (ACL), Natural grassland (NG), Alfalfa grassland (Medicago sativa L. (MS)), Spruce forestland (Picea asperata Mast. (PA)) and Cypress forestland (Platycladus orientalis (L.) Franco (PO))). The conversion of FL to grassland and forestland significantly increased C:N and C:P by 9.82~64.12%, 10.57~126.05%, and 51.44~113.40%, 22.10~116.09%, respectively. The conversion of FL to ACL reduced the C:N and C:P by 5.34~13.57% and 1.51~7.55%, respectively. The conversion of FL to NG can increase soil N:P. The conversion of FL to grassland and forestland increased soil MBC, MBN, and MBP by −31.54~84.48%, −48.39~1533.93%, −46.55~173.85%, and −34.96~17.13%, 68.72~432.14%, −38.39~318.46%, respectively. However, the MBC, MBN, and MBP contents in the soil converted from FL to ACL varied from −28.21~11.95%, 11.17~531.25%, and −82.64~70.77%, respectively. Soil SOC, TN, TP, available potassium (AK), pH, and soil bulk density (BD) are the main factors causing microbial biomass differences. These results indicate that converting farmland into forestland and grassland can improve soil nutrient structure and increase soil microbial biomass and carbon accumulation. The results of this study provide theoretical support for the scientific management of regional land.

Different fertilization measures affect the soil’s physical and chemical properties and bacterial community structure, which in turn affects the growth environment and yield of maize seed production. Therefore, rational fertilization measures are important in maintaining and improving soil fertility and promoting maize crop growth. Research on fertilization practices in maize fields for seed production can help to increase agricultural productivity while protecting and enhancing soil health and achieving sustainable agricultural development. To clarify the effects of different fertilization measures on soil bacterial communities in seed corn fields, 16S rRNA high-throughput sequencing technology and PICRUSt method were used to explore the soil under different fertilization measures (CK as control, effects of single application of liquid organic fertilizer (M), single application of bacterial agents (BF), and combined application of liquid organic fertilizer and bacterial agents (M + BF)) on soil bacterial community structure characteristics and ecological functions. Proteobacteria (20.14–25.30%), Actinobacteriota (18.21–20.47%), Actinobacteriota (13.55–22.00%), and Chloroflexi (14.24–17.59%) were the dominant phyla. Bacillus, RB41, Arthrobacter, and Sphingomonas were the dominant genera. M + BF treatment significantly increased the relative abundance of Planctomycetota. The relative abundance of Bacillus and PaeniBacillus in M treatment decreased considerably, while the relative abundance of Turicibacter increased significantly. The relative abundance of Sphingomonas was reduced considerably in M and M + BF treatments. The relative abundance of Subgroup 10 decreased significantly after BF and M + BF treatments. BF treatment significantly increased the relative abundance of Skermanella. Redundancy analysis showed that alkali-hydrolyzed nitrogen (p = 0.044) was the main environmental factor affecting soil bacterial communities under different fertilizer treatments. PICRUSt function prediction results showed that metabolism was the main functional component of bacteria, accounting for 78.45–78.94%. The abundance of functional genes for terpenoid and polyketone metabolism, the endocrine system, the excretory system, and the immune system of the soil bacterial community was significantly increased under M treatment, while the abundance of functional genes for the digestive system was decreased considerably. Different fertilizer cultivation measures changed soil bacterial community composition and ecological function in maize fields. These results can provide a theoretical reference for the study of bacterial community succession characteristics in maize fields and the determination of appropriate fertilizer cultivation measures.