Soil Water Consumption Research Articles

Biochar addition mitigates asymmetric competition of water and increases yield advantages of maize–alfalfa strip intercropping systems in a semiarid region on the Loess Plateau

ObjectiveUnbalanced competition for water poses a major challenge to intercropping systems in semiarid regions. The role of biochar as a soil amendment in regulating water balance and crop productivity is unclear. MethodsIn this two-year field trial, we investigated the impact of biochar application and method on the relationship between water balance utilization and productivity in maize–alfalfa strip intercropping. Monocropping [sole maize (SM) and sole alfalfa (SA)] and intercropping (I) systems were established, with biochar added to corresponding treatments (SMc, SAc, and Ic) and solely to intercropping alfalfa and maize (IAc and IMc). Results and conclusionsOur findings reveal that the yield of the intercropping system (I) was 11.4 % higher than expected on average. Biochar addition significantly increased forage production and water use efficiency, with similar benefits observed in monocropping systems. While competition ratio (CR) values reduce also reducing competition between maize and alfalfa. In two years, applying biochar solely to alfalfa (IAc) resulted in a higher land equivalent ratio (LER) and water equivalent ratio (WER) of 8.63 % and 12.73 %, respectively, compared with applying biochar solely to maize (IMc). Notably, yield and water use efficiency (WUE) increased the most when biochar was applied to intercropped maize and alfalfa (Ic), increasing by 16.1 %–16.6 % and 6.7 %–10.3 % compared with I, resulting in an increase in economic benefits by 24.9 %–26.3 %. Different biochar application methods showed significant potential in mitigating water competition in intercropping, with both sole and joint applications improving WUE, with the latter (Ic) demonstrating the most pronounced effect. However, excessive soil water consumption poses risks of water overuse, emphasizing the need to balance biochar utilization with water resource management. SignificanceOur findings highlight the ability of biochar to alleviate water competition imbalances and optimize water use in intercropping, providing a new approach for efficient water use in semiarid rain-fed agricultural systems.

Vegetation Restoration Increases the Drought Risk on the Loess Plateau.

The extensive implementation of the 'Grain for Green' project over the Loess Plateau has improved environmental quality. However, it has resulted in a greater consumption of soil water, and its overall hydrological effects remain highly controversial. Our study utilized a coupled land-atmosphere model to evaluate the effects of vegetation changes resulting from revegetation or reclamation on the hydrology of the Loess Plateau. Revegetation was found to stimulate an increase in precipitation, evapotranspiration, and atmospheric water content. However, the increase in precipitation was insufficient to compensate for soil water loss driven by intensified evapotranspiration, resulting in a decrease in both runoff and soil water content. In contrast to revegetation, reclamation would reduce precipitation, although the reduction was less than the decrease in evapotranspiration. This could lead to an increase in both runoff and soil water content. The results provide an important scientific basis for the hydrological effects of vegetation changes on the Loess Plateau, which is particularly important for guiding current and future revegetation activities toward sustainable ecosystem development and water resources management.

Effects of different mulching technologies on rainfed maize field energy exchange and evapotranspiration partitioning in northwest China

Artificial mulching, a prevalent water-saving tool in arid and semiarid agroecosystems, complicated energy exchange and water transport process between land surface and atmosphere. The field energy and evapotranspiration (ET) partitioning within a soil-mulch-plant-atmosphere continuum have not been comprehensively examined, which limited cognition of the underlying mechanisms that control hydrological processes and achieve yield improvement. Here, a four-season experiment in a rainfed summer maize field with four mulching treatments (NM: non-mulching, SM: straw mulching, RPBF: plastic-mulched ridge with bare furrow, and RPSF: plastic mulched ridge with straw-mulched furrow) was conducted to study the dynamics of surface energy and ET components and their regulation mechanisms. Results indicated that the effects of mulching on field energy partitioning were most evident at the maize initial stage, during which net radiation was significantly decreased under PM treatments (RPBF and RPSF), while soil heat flux was significantly reduced in SM treatments (p < 0.05). The average latent heat flux (LE) was 3.55 and 5.65 MJ·d−1 for NM maize at sowing and seedling stages, but decreased by 9.01 %, 27.04 %, 29.58 % at sowing, and 7.08 %, 9.56 % and 16.46 % at seedling stages for SM, RPBF and PRSF, respectively. The energy component differences among different treatments were minimal during the middle and late stages with high leaf coverage, and total LE and sensible heats were not significantly different. Mulch exerted a notable impact on soil evaporation (E) and crop transpiration (T), characterized by the average E of 0.96, 0.82, 0.57 and 0.46 mm·d−1 in NM, SM, RPBF and RPSF, while the value for T was 1.67, 1.88, 2.03 and 2.10 mm·d−1, respectively. PM conserved soil water by reducing E during the initial growing season and in dry periods, but also enhancing T and deepening the depth of soil water consumption under higher leaf cover. Energy exchange and ET partitioning were found to be more sensitive to soil water content (SWC) during periods characterized by lower leaf coverage, while the role of underlying canopy coverage characteristics overwhelmed soil properties in controlling energy and ET partitioning along with the leaf expansion. These findings contributed to a more comprehensive understanding of different mulching management on rainfed maize energy exchange and water use in Northwest China.

Modelling Eucalyptus globulus spatial distribution in the upper Blue Nile basin using multi spectral Sentinel-2 and environmental data

Eucalyptus plantations are widespread in the highlands of northern Ethiopia. The species has been used for centuries for various purposes. However, there are controversies surrounding the species with excessive soil nutrient and water consumption. Modelling the spatial distribution of the species is fundamental to understand its ecological and hydrological effects in the region for policy inputs. Therefore, the purpose of this study is to develop a model for mapping the spatial distribution of Eucalyptus globulus. We used the spectral bands of Sentinel-2 data, vegetation indices, and environmental data as predictor variables and three machine learning algorithms (Random Forest, Support Vector Machine, and Boosted Regression Trees) to model the current distribution of Eucalyptus globulus. Eleven of the twenty-five predictor variables were filtered using a variance inflation factor (VIF). 419 in situ georeferenced data points were used for training, and validating the models. The area under the curve (AUC), kappa statistic (K), true skill statistic (TSS), Root Mean Squared Error and coefficient of determination (R2) were used to validate the models’ performance. The model validation metrics confirmed the highest performance of Random Forest. The prediction map of Random Forest revealed that Eucalyptus globulus was fairly detected in non-Eucalyptus globulus woody vegetation (R2 = 0.86, P < 0.001; RMSE = 0.31). We found that the Green Normalized Difference Vegetation Index and environmental variables, such as elevation and distance from the road, were the most important predictor variables in explaining the distribution of Eucalyptus globulus. Our findings demonstrate that machine learning algorithms with Sentinel-2 spectral bands and vegetation indices compounded with environmental data can effectively model the spatial distribution of Eucalyptus globulus.

Optimizing Ridge–Furrow Ratio to Improve Water Resource Utilization for Wheat in the North China Plain

The shortage of water resources seriously limits sustainable production in agriculture, and the ridge–furrow planting pattern is an effective water-saving cultivation pattern. However, the mechanism of the ridge–furrow planting pattern that drives the efficient utilization of field water resources in the North China Plain (NCP) is still unclear. A two-year field experiment was conducted in the NCP from 2021 to 2023. The ridge–furrow planting patterns followed a randomized block design as follows: ridge–furrow ratios of 50 cm:50 cm (M2), 75 cm:50 cm (M3), and 100 cm:50 cm (M4). A traditional planting pattern was used as the control (M1). These were used to investigate the effects of different treatments on water use and roots. The results showed that M3 reduced the amount of irrigation, improved water distribution after irrigation, increased water use efficiency (WUE), and promoted root growth. Compared with other treatments, M3 increased soil water consumption at a 0–100 cm soil depth by 6.76–21.34% (average values over two years), root length density by 8.46–20.77%, and root surface area density by 7.87–22.13%. On average, M3 increased grain yields by 3.96–9.80%, biomass yields by 5.32–10.94%, and WUE by 4.5–9.87%. In conclusion, M3 is an effective planting pattern for improving the yield and WUE of wheat in the NCP.

Interaction Effects of Water and Nitrogen Practices on Wheat Yield, Water and Nitrogen Productivity under Drip Fertigation in Northern China

Water resource shortage and unreasonable application of nitrogen (N) fertilizer have been problems in wheat production of northern China. However, the interaction effects of water regimes and N practices on wheat root growth, grain yield, soil water, and inorganic N changes as well as water-N use efficiency are still unclear under drip irrigation. A field experiment was conducted during the 2020–2021 and 2021–2022 winter wheat (Triticum aestivum) growing seasons. In this study, three irrigation schedules (i.e., irrigation was applied up to 80% [D1], 75% [D2], and 70% [D3] as soon as the soil water content decreased to 65%, 60% or 55% of field capacity) and two N practices (i.e., N applied at the base, jointing, booting stages were 90, 72, 48 kg ha−1 [N1], and the base, jointing, booting, filling stages were 90, 40, 40, 40 kg ha−1 [N2], respectively) were considered. The decease in irrigation water amount was offset by the increase in soil water consumption. In addition, N practices significantly interacted with irrigation on soil NO3−–N accumulation (2021–2022), NH4+–N accumulation, SPAD value (2020–2021), N content in stems and grains at maturity, and average root length and weight density at the flowering stage. Irrigation, rather than N practices, significantly affected grain yield, total N uptake, crop N transformations (NT), the contribution of NT to grain (NTPC), water and N productivity, in which, for the value of these two seasons, D2 increased total N uptake by 18.1% (p &lt; 0.05), and NT by 39.4% (p &lt; 0.05) under N1 as compared to D3. Additionally, the highest WUE and ANUE were found in D2 during 2021–2022. Heavy irrigation water amount caused high a LAI; further analysis proved that the LAI was the key factor affecting grain yield, and positively and significantly correlated to yield. However, no significant difference in the LAI between D1 and D2 was found. N1 was beneficial to prevent N leaching and increase water and N use efficiency, biomass, and N transformation amount. This study recommends that D2 + N1 might be a promising system for manipulating irrigation and fertilization practices under sub-surface drip irrigation systems to improve water and N use efficiency and grain yields in semi-arid regions.

Rational optimization of irrigation regimes for drip-irrigated cotton fields without mulch can alleviate the problem of residual film contamination in arid zones

The serious problem of residual film pollution in the arid region of northwestern China has a severe negative impact on both the farmland environment and the benefits of cotton planting. Drip irrigation without mulch (DIWM) has the potential to serve as an effective alternative to mulch drip irrigation and address the issue of residual film pollution. However, there are few studies on how to formulate a rational irrigation regime under DIWM conditions and achieve water savings and productivity gains. Consequently, from 2020 to 2021, we established three DIWM treatments: W4, W6, and W8. None of the treatments were irrigated at the seedling stage, and the irrigation regime was the same for all the treatments at the squaring stage (2 irrigations at an irrigation quota of 45 mm). From the initial flowering stage, the frequency of irrigation was once every 6 d, 8 d, and 12 d for W4, W6, and W8, respectively, and the corresponding total numbers of watering times were 8, 6, and 4, respectively. The irrigation amount was 69 mm at each time point during the flowering and boll-forming stages in all the treatments, and the final irrigation amount was 52.2 mm in W8. The total irrigation amounts were 366 mm, 504 mm and 625.2 mm for W4, W6 and W8, respectively. This study explored the spatiotemporal characteristics of soil moisture via sensors combined with the spatial grid method. Additionally, the growth indices, biomass accumulation, yield components, and water use efficiency (WUE) of cotton were assessed across various treatments. The results revealed that, in 2020 and 2021, the W8 treatment resulted in the highest soil water content (SWC) in the 70–110 cm soil layer and soil water consumption (WC) in the 10–110 cm layer, with the WC in the 10 cm layer being 20 % and 44 % greater than that in W6, respectively. The excessive total irrigation amount (IA) in the W8 treatment led to high vegetative growth of cotton, diminishing the positive impact on yield. Across both years, the WUE observed in the W6 treatment significantly exceeded that of W8, while the seed cotton yield demonstrated only marginal decreases of 5 % and 0.9 % compared with that of W8. The irrigation amount and average WC in the 10–40 cm soil layer were 19 % and 29 % lower in W6 than in W8, respectively, but the economic benefits were only 2 % lower than those in W8. There was a significant positive correlation between the SWC and WC in all the different soil layers, and the effect of the SWC on the WC gradually decreased with increasing soil depth. Overall, the irrigation regime employed in the W6 treatment within the arid zone, devoid of mulch cover, proves to be an effective water-saving strategy, ensuring a consistent cotton yield and enhancing WUE. This study serves as a reference for developing an efficient irrigation system tailored to the DIWM cotton industry in arid zones, contributing to the promotion of green and sustainable agricultural development in this region.

Soil water consumption along the profile in response to soil water content variations in a black locust plantation with a rainfall exclusion in Loess Plateau

Soil drying is frequently observed in mature forests in water-limited regions, and poses a threat to sustainable development of the ecosystems. Herein, we assessed the effects of rainfall reduction on the water-use characteristics of a black locust (Robinia pseudoacacia) plantation in a sub-humid region of the Loess Plateau, China. Paired plots were established in the plantation, including a treatment with 30 % throughfall exclusion and a control. We comparatively investigated the dynamics of soil water content (SWC) throughout the profile in the two plots after four years of the treatment and determined the contribution of soil water storage (SWS) in each soil layer to water consumption according to the SWS budget. While SWC across the profile in the control plot showed general responses to replenishment and consumption under rainy and dry weather conditions, respectively, the treatment plot had smaller replenishment and consumption in deep layers, causing an aggravated deficiency in SWS and the formation of a temporary dried soil layer (DSL) at a depth of 55–100 cm. The cumulative decrement in SWS during each dry event (consecutive rainless days of ≥ 5-day duration) in the control plot was significantly correlated with SWC at 100–160 cm, suggesting a substantial contribution of water consumption from this layer. However, the treatment plot showed a major contribution to water consumption from the 0–100 cm soil layer during dry events. The vertical distribution of the root system supports these findings, which differed from our hypothesis that deep soil water would be used in response to reduced rainfall input. The distribution of fine root density in the treatment plot was relatively shallower (0–22 and 0–73.1 cm accounting for 50 % and 90 % of fine roots, respectively) than in the control plot (0–31.2 and 0–103.5 cm for corresponding values). These findings indicate that soil water deficiency resulted in the formation of DSL, which hindered water consumption and root development deeper in the soil profile. The severity and recovery of the DSL may be jointly determined by the vertical distribution of SWS and transpiration demand of the plantation. These findings provide insights for water resource management and sustainable development of the plantations in this region.

Additional organic and bacterium fertilizer input regulated soybean root architecture and dry matter distribution for a sustainable yield in the semi-arid Region of China.

In the dryland area of the Loess Plateau in northwest China, long-term excessive fertilization has led to soil compaction and nutrient loss, which in turn limits crop yield and soil productivity. To address this issue, we conducted experiments using environmentally friendly organic fertilizer and bacterium fertilizer. Our goal was to investigate the effects of additional organic and bacterium fertilizer inputs on soil water migration, crop root architecture, and yield formation. We implemented six different fertilizer strategies, namely: Nm (mulching, N 30 kg/ha), NPK1m (mulching, N 60 kg/ha; P 30 kg/ha; K 30 kg/ha), NPK2m (mulching, N 90 kg/ha; P 45 kg/ha; K 30 kg/ha), NPKOm (mulching, N 90 kg/ha; P 45 kg/ha; K 30 kg/ha; organic fertilizer 2 t/ha), NPKBm (mulching, N 60 kg/ha; P 30 kg/ha; K 30 kg/ha; bacterium fertilizer 10 kg/ha), and N (N 30 kg/ha; no mulching). The results revealed that the addition of bacterium fertilizer (NPKBm) had a positive impact on soybean root system development. Compared with the other treatments, it significantly increased the total root length, total root surface area, and total root length density by 25.96% ~ 94.89%, -19.63% ~ 36.28%, and 9.36% ~ 28.84%, respectively. Furthermore, NPKBm enhanced soil water consumption. In 2018, water storage during the flowering and podding periods decreased by 12.63% and 19.65%, respectively, while water consumption increased by 0.97% compared to Nm. In 2019, the flowering and harvest periods decreased by 23.49% and 11.51%, respectively, while water consumption increased by 0.65%. Ultimately, NPKBm achieved high grain yield and significantly increased water use efficiency (WUE), surpassing other treatments by 76.79% ~ 78.97% and 71.22% ~ 73.76%, respectively. Subsequently, NPK1m also exhibited significant increases in yield and WUE, with improvements of 35.58% ~ 39.27% and 35.26% ~ 38.16%, respectively. The use of bacterium fertilizer has a profound impact on soybean root architecture, leading to stable and sustainable grain yield production.

Improvement of grain weight and crop water productivity in winter wheat by light and frequent irrigation based on crop evapotranspiration

Efficient use of scarce water resources to maximize yield and crop water productivity (WPc) is a common goal of sustainable and ecological agriculture in the North China Plain. To clarify whether light and frequent (LF) irrigation under the same or reduced amount of irrigation is beneficial to achieve this goal, and to further tap the water saving potential. Based on drip irrigation conditions, a three–year (2020–2023) field experiment was conducted to investigate the effect of four irrigation treatments (CK, conventional irrigation at the jointing and anthesis stages; LF1, 100 % ETc, ETc is the crop evapotranspiration; LF2, 75 % ETc, LF3, 50 % ETc) on yield, water consumption characteristics, leaf photosynthetic physiology and grain filling process. The results showed that compared with CK, LF1 and LF2 significantly increased the photosynthetic rate and chlorophyll content of flag leaves at 18 days after anthesis, promoted grain filling, and finally enhanced dry matter accumulation after anthesis, 1000–grain weight (TGW) and grain yield. LF irrigation management mode also increased the consumption of deep soil water (1.4–2.0 m), reduced soil water consumption and evapotranspiration, and significantly improved WPc and irrigation water productivity. However, LF1 and LF2 did not have significant yield enhancement in the wet year, but had one less irrigation than in the normal year. The LF2 achieved the highest WPc in three years (2.1 kg m–3), in the 25 % (37.5 mm) and 40 % (60 mm) less irrigation water in the normal and wet years, respectively. Meanwhile, the LF3 treatment reduced the number of spikes, TGW and dry matter accumulation to different degrees in three years, resulting in significantly lower yields (13.9 %–18.4 %), which cannot be used as a reference for an efficient irrigation system. Therefore, LF irrigation based on 75 % ETc is the best irrigation strategy to improve water utilization and yield in the North China Plain.

ABA-receptor agonist iSB09 decreases soil water consumption and increases tomato CO2 assimilation and water use efficiency under drought stress

Climate change can alter precipitation patterns, disrupting the natural water cycle and generating drought periods that negatively impact crop yield or plant survival. Novel biotechnological approaches are being developed to face water deficits. Specifically, molecular knowledge of the plant hormone abscisic acid (ABA) can be harnessed to develop genetic and chemical approaches to cope with abiotic stress. ABA receptor agonists are promising molecules that activate ABA signaling on demand and show long-lasting effects, in contrast to the exogenous application of ABA, which has a short half-life. In this work, we studied the effect of the iSB09 agonist on tomato plants grown under drought stress or well-watered conditions. iSB09 treatment induced stomatal closure in tomato through activation of PYL1-like and PYL4-like ABA receptors. Additionally, RNA-seq analyses reveal coordinated upregulation by ABA or iSB09 of the genes encoding enzymes involved in the synthesis of the osmoprotective galactinol and raffinose family of oligosaccharides. Foliar spraying of iSB09 under drought conditions anticipated the regulation of transpiration, promoted drought avoidance and increased water use efficiency in tomato plants. Physiological analysis of agonist-treated plants reveals increased CO2 assimilation and effective quantum yield of the photosystem II under drought conditions in iSB09-treated plants compared to mock-treated. Faster regulation of transpiration at the start of the drought period was achieved by iSB09 treatment, and, as a result, water consumption was reduced compared to mock-treated plants. Overall, the agonist treatment mounts the genome-wide transcriptional response to stress and increases water use efficiency under drought conditions and plant protection.

Modeling Nitrogen Fate and Water and Nitrogen Use Efficiencies under Different Greenhouse Vegetable Production Systems Using the WHCNS-Veg Model.

Quantitative evaluation of the effects of diverse greenhouse vegetable production systems (GVPS) on vegetable yield, soil water consumption, and nitrogen (N) fates could provide a scientific basis for identifying optimum water and fertilizer management practices for GVPS. This research was conducted from 2013 to 2015 in a greenhouse vegetable field in Quzhou County, North China. Three production systems were designed: conventional (CON), integrated (INT), and organic (ORG) systems. The WHCNS-Veg model was employed for simulating vegetable growth, water dynamics, and fates of N, as well as water and N use efficiencies (WUE and NUE) for four continuous growing seasons. The simulation results revealed that nitrate leaching and gaseous N emissions constituted the predominant N loss within GVPS, which separately accounted for 11.5-59.4% and 6.0-21.1% of the N outputs. The order of vegetable yield, N uptake, WUE, and NUE under different production systems was ORG > INT > CON, while the order of nitrate leaching and gaseous N loss was CON > INT > ORG. Compared to CON, ORG exhibited a significant increase in yield, N uptake, WUE, and NUE by 24.6%, 24.2%, 26.1%, and 89.7%, respectively, alongside notable reductions in nitrate leaching and gaseous N loss by 67.7% and 63.2%, respectively. The ORG system should be recommended to local farmers.

Response of deep soil water deficit to afforestation, soil depth, and precipitation gradient

In semi-arid and semi-humid regions, deep soil water resources are crucial for vegetation restoration to mediate the ecosystem sustainability. Yet it is still limited on understanding soil water deficit (SWD) caused by vegetation restoration and its response to soil depth and precipitation. To obtain a more accurate measurement of regional SWD, we conducted a two-year soil water monitoring to a depth of 1800 cm under typical vegetation restoration with a precipitation gradient ranging from 300 mm/y to more than 600 mm/y across the Loess Plateau of China. With increasing precipitation gradient, soil water storages in 0–1800 cm depth under both arable cropland and artificial vegetation significantly increased (p < 0.05). Compared to arable cropland, artificial vegetations (forest and shrub) had a significantly greater SWD regardless of either precipitation gradient or soil depth. In particular, the deep-rooted vegetations (R. pseudoacacia and C. korshinskii) on the Loess Plateau demonstrated the greatest SWD in the 0–1800 cm layer due to their great water consumption. Indeed, a positive relationship between the accumulated SWD and the accumulated root biomass was detected, suggesting that the increased root biomass in soil depth may promote soil water consumption. In addition, the relative SWD in artificial vegetation at a depth of 1800 cm decreased significantly (p < 0.05). These findings reveal that there is a mechanism of precipitation self-regulation on the deep SWD, of which is more sensitive in the sub-shallow soil layers. We conclude that the SWD depends on vegetation restoration, soil depth, and precipitation self-regulation, offering a reference for how afforestation affects deep soil water in the Loess Plateau region. This finding also benefits to mediate water balance processes and develop sustainable land management in water-limited regions around the world.

Will large-scale forestation lead to a soil water deficit crisis in China's drylands?

Trading water for carbon has cautioned large-scale afforestation in global drylands. However, model simulations suggested that the consumption of soil water could be partially offset by increasing precipitation due to vegetation feedback. A systematic meta-analysis of long-term and large-scale field observations is urgently required to address the abovementioned limitations, and the implementation of large-scale afforestation since 1978 in northern China provides an ideal example. This study collected data comprising 1226 observations from 98 sites in northern China to assess the variation in soil water content (SWC) with stand age after afforestation and discuss the effects of tree species, precipitation and conversions of land use types on SWC. We found that the SWC has been decreased by coniferous forest and broadleaf forest at rates of 0.6 and 3.2 mm decade–1, respectively, since 1978. There is a significant declining trend of SWC with the stand age of plantations, and the optimum growth stage for plantation forest is 0–20 a in northern China. However, we found increases in SWC for the conversion from grassland to forest and in the low-precipitation region, both are corresponding to the increased SWC in coniferous forest. Our study implies that afforestation might lead to a soil water deficit crisis in northern China in the long term at the regional scale but depends on prior land use types, tree taxa and the mean annual precipitation regime, which sheds light on decision-making regarding ecological restoration policies and water resource management in drylands.

Soil water movement may regulate soil water consumption and improve cotton yields under different cotton cropping systems

By quantifying the soil water movement (SWM) in crop planting systems, we can better understand the soil water consumption (SWC) and crop yield relationship; this finding is significant for determining the field water cycle and reducing agricultural water waste. In this paper, a case study was conducted on cotton production. Soil moisture sensors were set at depths of 10–110 cm under three cotton cropping systems (monoculture cotton (MC), wheat/delayed intercropped cotton (WIC), and wheat/direct-seeded cotton (WDC)) based on spatial grid methods; a geostatistical grid calculus was used to calculate SWM; and the crop and meteorological influence mechanisms on cotton lint yield were comprehensively analyzed. At the squaring stage, SWC and vertical SWM were significantly correlated with light, temperature and water conditions. At the flowering and boll development stage, SWC and vertical SWM were collectively affected by meteorological conditions and crops, and they were positively correlated with lint yield. The aboveground and belowground biomass accumulation at the flowering and boll development stage positively affected vertical SWM in and between cotton rows. Vertical SWM in cotton rows increased SWC in cotton rows. SWC in cotton rows and aboveground biomass positively impacted lint yield formation; SWC between rows negatively impacted lint yield. The SWC and vertical SWM between rows in the MC seedling stage exceeded those in cotton rows, and more precise irrigation at the seedling stage reduced water waste. The WIC horizontal SWC at the squaring and flowering and boll opening stages was relatively high, moving from the row midline to cotton row. A better SWC distribution in and between cotton rows promoted water utilization in the cotton rows; this method was feasible for improving cotton yield in diverse planting systems. The results could optimize precision irrigation management at different cotton growth stages and provide a theoretical reference for promoting sustainable agricultural production and climate adaptation.

Effects of inorganic mulching on soil hydrothermal environment and tomato characters in the presence of unheated greenhouse cultivation

The present study was conducted by cultivating tomato (Solanum lycopersicum ‘Provence’) using varied inorganic mulching to investigate soil hydrothermal environment and tomato characters under unheated greenhouse cultivation in the cold zone of China. A total of 6 different treatments were adopted: no mulching (control), white film mulching (white film), black film mulching (black film), the white film with hole mulching (white hole), the black film with hole mulching (black hole), and snake skin bag mulching (snake skin). Inorganic mulching treatment significantly improved soil temperature and moisture, water use efficiency, tomato yield, and reduced soil water consumption. There was no significant difference observed in the variation of daily mean soil temperature between different mulching treatments, and the variation was in the range of 1.95–2.20 °C, which was significantly lower compared with the control (3.42 °C). The daily mean soil moisture varied significantly after different mulching treatments, with the highest level achieved by snake skin (23.37%), followed by black hole (22.55%), white hole (22.08%), white film (21.48%), black film (20.12%), and control (18.78%) in descending order. According to the research results, plastic-hole mulching, which include white hole and black hole treatments, performed better in maintaining soil temperature and moisture.

Long term response and adaptation of farmland water, carbon and nitrogen balances to climate change in arid to semi-arid regions

Climate change poses a challenge for resource utilization and environmental pollution issues caused by agricultural production, especially in arid to semi-arid regions. Farmland water, carbon and nitrogen balances are closely related to these resource and environmental issues. Thus, the Agro-Hydrological & chemical and Crop systems simulator was used to assess the response of water, carbon and nitrogen balances to climate change in a spring wheat farmland of arid to semi-arid Northwest China and to propose adaptation strategies. Five Global Climate Models from the Coupled Model Intercomparison Project 6 and two Shared Socioeconomic Pathways (SSP1–2.6 and SSP5–8.5) were used to establish scenarios with the Agro-Hydrological & chemical and Crop systems simulator to simulate farmland water, carbon and nitrogen balances for the 2025–2100 period. Various irrigation amounts and nitrogen fertilization rates were tested as compensation strategies. Results indicated that climate change could negatively affect farmland water, carbon and nitrogen balances, especially under the SSP5–8.5 scenario. Precipitation showed an increasing trend, thus percolation increased and soil water consumption decreased from 2025 to 2100. However, for the carbon budget, although the soil carbon dioxide emissions tend to decrease, the net primary production was also significantly reduced, which resulted in declining the net ecosystem carbon budget under future climatic conditions. In addition, higher temperature and increased precipitation enhanced soil inorganic nitrogen leaching and nitrous oxide emissions but reduced ammonia volatilization from 2025 to 2100. Overall, the soil total nitrogen loss was increased over time, whereas crop nitrogen uptake was significantly reduced. In relation to the SSP1–2.6 scenario, the SSP5–8.5 scenario accelerated the increase rates of soil water percolation and total nitrogen loss over time, as well as the decrease rates of crop nitrogen uptake and net primary production over time. The negative effects caused by climate change can be mitigated by reducing irrigation and increasing nitrogen fertilization. For the SSP1–2.6 scenario, 30% irrigation reduction and 30% nitrogen fertilization increase can effectively decrease soil water percolation and the related nitrogen losses while crop nitrogen uptake, net primary production and net ecosystem carbon budget increase in relation to the current management (irrigation = 240 mm and nitrogen fertilization = 200 kg ha–1). For SSP5–8.5 the strategy with 45% irrigation reduction and 45% nitrogen fertilization increase can also decrease nitrogen losses and increase crop nitrogen uptake, net primary production and net ecosystem carbon budget.

SIMULATION MODELING AND PRACTICAL USE OF THE HYDROLOGICAL FUNCTION OF DETRITUS IN SOIL ENGINEERING TECHNOLOGIES

The high water retention and water capacity functions of detritus determine its potential hydrological signifi cance in the formation of the water regime of soils and phytoproductivity of forest landscapes. Using computer modeling of water exchange in the “soilplantatmosphere” HYDRUS1D system, we preliminary studied the hydrological function of detritus for water retention of precipitation and root water consumption at different amounts and variants of the arrangement of detritus layers in the soil profi le. The soil structures designed on the basis of this information for sustainable afforestation with increased carbon sequestration demonstrated in field experiments with water balance monitoring high eficiency in optimizing the water retention capacity of the soil and roots water consumption of the test crop (Glauca spruce) with a 23fold reduction in unproductive water losses and a 1.5-2fold increase in the current plant growth relative to untreated control. The physical mechanism of the detritus hydrological function is the formation of capillary barriers blocking evaporation and capillary resorption of soil water due to due to surface accumulation (forest litter) or placement in layers inside the soil (peat layers in constructosems).

Agronomic and reclamation strategies to enhance soil fertility, productivity and water accessibility

IntroductionOver the last decade, yields and profitability of crops on agricultural lands in the Kyzylkum irrigation massif in the south of Kazakhstan, as well as soil fertility, have been decreasing. The Kyzylkum irrigation basin, located in the Syrdarya River basin, is affected by various factors such as agronomic practices, reclamation factors, and human activities including tourism. This study aims to monitor the yields of cotton and alfalfa in alfalfa-cotton crop rotations in the Kyzylkum irrigation massif, assess soil fertility after alfalfa and cotton cultivation under production conditions, and evaluate the profitability of water consumption.MethodsThe research methodology involved experimental and observational studies conducted on a nine-pole alfalfa-cotton crop rotation area in the Kyzylkum basin within the Syrdarya river basin. The study was conducted on three farms: Didar, Toishy, and Ali-Myrza. Productivity, soil fertility after crop cultivation, and profitability of water consumption were determined through these studies.ResultsThe study found that the Ali-Myrza farm experienced a 21% increase in cotton yield, a 24% increase in alfalfa yield, a 36% increase in profit from crop rotation, a 34% increase in profitability, and a 5-6% increase in water consumption. After alfalfa rotation, the Ali-Myrza farm recorded the highest cotton yield at 3.5 t/ha and a profit of 1,316 euros/ha. However, in the following year, cotton yields decreased to 2.52 t/ha, and profits dropped to 576 euro/ha. The first year of alfalfa cultivation resulted in a yield of 10 t/ha and a profit of 462 euro/ha, which increased to 14 t/ha and 967 euro/ha in the subsequent year. Soil analysis revealed that after two years of growing alfalfa in a six-pole rotation, the root mass in the top 20 cm of soil reached 8.89 t/ha. In contrast, rotations with seven (Toishy) and nine (Didar) crops resulted in lower root masses of 4.68 t/ha and 3.47 t/ha, respectively. The corresponding humus content was 1.65%, 1.40%, and 1.1%, respectively.DiscussionComparing the seven and nine-pole rotations of alfalfa and cotton, the six-pole rotation demonstrated significant improvements in soil fertility (30-40% increase), cotton yield (18-23% increase), alfalfa yield (20-28% increase), and water consumption (5-6% increase). These findings confirm the effectiveness of the alfalfa-cotton rotation method in enhancing soil fertility, productivity, water efficiency, and grey soil productivity in Kyzylkum irrigated fields. The results obtained from this study can be applied in cotton farms in South Kazakhstan that use nine-layer cotton and alfalfa rotations. Furthermore, the findings have implications for cotton cultivation in any country worldwide.

Hydrological niche regulation induced by different resistance strategies facilitates coexistence of P. longipes and L. communis under drought stress.

Under global warming, the availability of water resources is one of the most important factors affecting trait evolution and plant species distribution across terrestrial ecosystems, and the relationships between drought resistance strategies and the hydrological niche characteristics of plants are worth studying. We continuously monitored physiological drought response parameters such as gs , Tr , proline, soluble sugar, gene expression and activities of SOD, POD, and CAT to assess drought resistance strategies of Platycarya longipes and Lindera communis; determined plant soil hydrological niche separation by stable H and O isotope analysis; and analysed the effects of interspecific water competition by comparing the differences in morphological and physiological parameters between solo and mixed planting. Under drought stress, L. communis exhibited a drought avoidance strategy, and P. longipes exhibited a drought tolerance strategy. L. communis utilized the water within the shallow soil layer, while P. longipes mainly utilized the water in the deeper soil layer; there were fewer parameters with significant differences between the solo planting and the mixed planting of L. communis compared to P. longipes. Overall, P. longipes benefited from coexistence with L. communis under drought stress, which may be because L. communis employs a drought avoidance strategy, reducing soil water consumption in the drought environment. These results suggested that differences in functional traits or resistance strategies among species benefit species' coexistence in a community under drought stress.