Crop models may potentially explore alternative ways to improve agroecosystem resilience in arid regions of Middle East and North Africa. Mapping the outputs behavior as a function of the inputs and quantifying the uncertainty contribution of inputs to the variability of outputs are crucial for understanding and applying complex mathematical models to a new environment. Objectives of present research are (i) to calibrate and evaluate the Decision Support System for Agrotechnology Transfer (DSSAT) cropping system model using detailed experimental datasets on maize production in arid sandy soils (Entisol) and (ii) to determine the model's sensitivity to soil, genotype and crop management inputs under the currently explored conditions (low fertility and water holding capacity) based on multivariate analysis and variance decomposition methods. The goodness-of-fit statistics between observed and simulated data indicated that the calibrated model reasonably well simulates maize phenology, growth and yield, evapotranspiration, soil water content, grain N concentration, and postharvest soil NO3-N in eight year site field experiments. A global sensitivity analysis using the co-inertia method was carried out to link 14 output variables and 25 soil and genotype input parameters. Maize growth and yield variables were strongly correlated with soil hydrological and fertility input parameters such as soil water upper limit (SDUL) and soil organic carbon (SOC), whereas simulation of maize phenology was largely determined by phenological genotype-specific cultivar input parameters. A strong association was also observed between the output variables of yield and soil fertility. The effect of carbon (C) related soil input parameters of initial SOC and stable SOC and crop management factors of maize residue retention and compost application under no-till system on the long-term (10 years) simulation of yield and SOC dynamics was further explored using Sobol' method. Simulated grain yield, water productivity, active SOC, and cumulative soil CO2 efflux were most sensitive to initial stable SOC and compost application. Maize residue retention significantly affected the simulation of cumulative N mineralization, SOC % in 0.2 m depth, and cumulative soil CO2 efflux through interactions effect, i.e. total-order sensitivity index (S-Ti) > 0.05, with other inputs. Compost application increased grain yield by 13 %, SOC stock by 5%, and cumulative soil CO2 efflux by 95 % compared with no application. However, compost application with maize residue retained significantly reduced cumulative soil CO2 efflux by 12 % compared with compost application with maize residue removed. Therefore, the application of compost with maize residue retained under no-till system is a plausible crop management option for agronomically improved and environmentally sound maize production in arid sandy soils.

Moringa oleifera is becoming more popular in Egypt as leafy vegetable crop. The current investigation was conducted in order to determine the ideal nitrogen application strategy for moringa leaf production. Two field experiments were carried out in sandy soil in open field of the Experimental Station of the National Research Centre (2013 and 2014). Moringa seeds were sown 30 cm between rows, 15 cm between hills, double plants per hill, on February 15th in both growing seasons. This study aimed to obtain the best fertilization strategy for moringa when grown as a leafy vegetable crop. Recommended fertilization supplement of 150:125:100 kg NPK ha(-1) were applied for all treatments. In addition, 25 kg N ha(-1) was applied after each cutting. Ammonium sulfate (21.5% N) was used as mineral M source, plant compost (2% N) was used organic O nitrogen source and a mix of Azospirillum spp. and Acetobacter spp. Nitrobin was used as bio-nitrogen B source. The effect of five nitrogen fertilization strategies were investigated i.e., 1) 100% M, 2) 50% M + 50% O, 3) 50% M + 50% O + B, 4) 25% M + 75% O, 5) 25% M + 75% O + B. The whole plant canopy was cut 5-10 cm above soil surface, three times, 90, 135 and 180 days after sowing, as green yield. Plant growth parameters (plant length, stem thickness, leaf number, leaf area, plant fresh and dry weight) were recorded each cutting time. Nitrogen, vitamin C, carotene, Ca, Zn and Fe content were determined. Moreover, total canopy yield was recorded. The full mineral treatment gave the best results but the 50% M + 50% O + B nitrogen fertilization strategy can alternatively be followed. However, the lowest value for all investigated parameters were obtained when 25% M + 75% O without bio-enrichment followed. Accordingly, it could be recommended to fertilize moringa grown in sandy soil with 150:125:100 kg NPK ha(-1), in addition to 25 kg N ha(-1) applied after each cutting using nitrogen source consisting of 50% Ammonium sulfate + 50% plant compost + Nitrogen Fixing bacteria enrichment after emergence in order to produce higher leaf yield with good quality.

The coal mining subsidence land of the Northern of Shaanxi mining area is arid, and mining disturbance will aggravate soil sandification and soil impoverishment, thus the difficulty in planting. This study aims to investigate the influence of different inoculation methods on corn growth and its improvement effect on degraded soil through the inoculation of the functional microorganisms AMF (G.i) and PSM (B.m) by regarding vegetable residue and urea as soil fertilizer and corn as the test plant. Results show that G.i and B.m inoculation can significantly increase the biomass of corn plants, with significantly increasing N, P, and K contents in corn. The combined application of G.i and B.m has the best improvement effect on degraded soil. The contents of available phosphorus, nitrogen, and potassium in the rhizosphere soil of corn are increased by 141%, 109%, and 116%, respectively. Acid phosphatase and alkaline phosphatase activities in soil are significantly improved, and the organic matters in the rhizosphere soil treated with mixed inoculation are increased by 95%. The glomalin secreted from G.i is an important carbon pool for degraded soil. The total glomalin in the rhizosphere soil increases to 5.82mg/g in the mixed inoculation group and reaches 4.1mg/g in the G.i single inoculation group. This result shows that G.i and B.m can promote plant growth, with the improvement effect on degraded soil in the mining area. Therefore, the application of G.i and B.m in Sandy soil should be promoted.

A research dealing with the effect of ameliorants on jack bean cultivated in marginal soils i.e. sandy, grumusol, and podsolic soil can be an interesting report. This research was carried out in dry season in 2017, 2018, and 2019 for sandy, grumusol, and podsolic soil respectively. The research relating with the cultivation of jack bean in sandy soil was conducted in sandy beach area of Kulonprogo Regency, Yogyakarta. Whereas, the research dealing with the cultivation of jack bean in grumusol as well as podsolic soil were carried out in Gunung Kidul Regency, Yogyakarta. Kinds of ameliorants i.e. chicken, goat, cow, and green manure were used as factor of the treatments. The variables of leaf number, productive branch number, and plant height were observed. Results of the research indicated that the application of chicken manure gave better growth of plant canopy of jack bean in sandy, grumusol, as well as in podsolic soil, except in grumusol soil there were no significantly different of ameliorant application on the productive branch number of the plants.

To improve the natural environment of arid and desert areas and to protect sand vegetation, we take estimation of the aboveground biomass of Haloxylon ammodendron in the Liangucheng National Reserve as our research object in this study, using SPSS and Excel software for data analysis and processing. Models for estimating aboveground biomass in sandy and gravel soil were established, and the results showed that this value for H. ammodendron was significantly correlated with basal diameter and plant height, as well as their complex variables. The best estimation models in sandy and gravel soil are W = 0.138 (DH)(1397) and W = 0.189 (DH)(1433), which have prediction accuracies of 82.825% and 83.688% and average relative errors of 14.392% and 13.455%, respectively. These models have high fitting precisions and can be used to estimate the biomass of H. ammodendron.

Vegetation restoration is one of the most effective methods to control soil desertification. The change of the input and decomposition of soil organic matter (SOM) in the process of vegetation restoration not only affects the restoration of its own ecosystem, but also affects the biogeochemical cycle of soil carbon. In addition, the soil texture and the conversion and accumulation of organic carbon are also improved by vegetation restoration. Dissolved organic matter (DOM), an important component of SOM, can effectively evaluate the vegetation restoration status of desertification soil in arid area. However, the evolution and spectral characteristics of DOM in sandy soil with different restoration methods and vegetation types (such as grassland, shrub, coniferous forest. deciduous forest, etc.) are not well understood. Mu Us Sandy Land is located in the transition zone between desert steppe and forest steppe in the northwest of China, which is one of the four typical sand areas in China. In recent years, the restoration of Mu Us Sandy Land has achieved obvious results through engineering technologies such as sand-fixing plants, aerial seeding and soil recombination. In this study, the surface soil of three types of soils (sandy land, newly improved land and plant-covered land) was collected in Mu Us Sandy Land. In the present study, the source, content and composition of the DOM of soil under different land improvement measures and vegetation types (sandy land. SL; newly improved land, NL and plant-covered land, PL) in Mu Us Sandy Land were investigated using ultraviolet-visible spectral (UV-Vis) and fluorescence excitation-emission matrix spectrophotometry (EEM) with parallel factor analysis (PARAFAC), the correlation analysis and principal component analysis (PCA). Results showed that DOM content and DOC/SOC value were significantly under different types of land and vegetations cover. The proportion of dissolved organic carbon in shrub land and tree land showed an opposite trend to its content of dissolved organic carbon. Compared with bare sandy land, soil modification and vegetation cover significantly enhanced the content of DOC and the stability of SOC. Moreover, the stability of organic carbon in arbor covered land was slightly higher than that in grassland and shrub land. PARAFAC showed that the DOM of sandy land was mainly composed of tryptophan-like (C3), while the DOM of modified soil and vegetation covered land was mainly composed of humic acid-like (C1 and C2). Negative correlation between C1 and C3. C2 and C3 (*P herb>shrub, and relative content of humic acid increased with the increased restoration years. DOM fluorescence index (FI value) decreased, biological index (BIX value) and humification index (HIX value) significantly increased in vegetation-covered soil, compared with SL and NL, which indicated obvious tenigenous characteristics, confirming the enhancement of organic carbon stability. The humification degree of soil in arbor area was higher than that in shrub land and grassland. Overall, compared with NL and SL. vegetation restoration process. especially the planting of arbor can contribute to the storage of soil organic carbon, increasing the content and the stability of DOM. This study provides a theoretical support and reference for the improvement of Mu Us Sandy Land management and it helps to provide a scientific basis for the accurate evaluation of soil improvement and ecological effects of vegetation restoration in sandy land. It will provide theoretical support for understanding the biogeochemical cycle of carbon in sandy land.

Many problems are encountered in the disposal of abundant magnesium slags, remarkable ecological environmental damages by stacking and landfill of magnesium slag, poor properties of soil-rock materials, and high pavement cost in Yulin City, China. This study focused on the combined use of feasibility of magnesium slag-Aeolian sand in pavement base to address the problems above. The physical and chemical properties of magnesium slag and Aeolian sand were obtained through tests on the basic properties of raw materials. Different mixing ratios of magnesium slag and Aeolian sand and cement content were designed. Moreover, a comparative study on the compaction characteristics and water stability, as well as unconfined compressive strength, splitting strength, and compressive modulus of resilience of five groups of cement-stabilized magnesium slag-Aeolian sand mixtures in different periods, was conducted through a series of systematic laboratory tests. The impact degrees of different factors on compressive strength were calculated by the grey relational analysis method. Finally, the test was paved by combining laboratory test results. Research results demonstrate that the active matter content is high, and the crushing value of magnesium slag is also high. The optimal water content of the mixture increases with the magnesium slag content, while the maximum dry density decreases. The mixture's unconfined compressive strength, splitting strength, and compressive modulus of resilience in different curing periods all increased with the magnesium slag and cement contents. Moreover, magnesium slag content has minimal influence on splitting strength compared with unconfined compressive strength. Among all factors, cement content provides the most influence on the compressive strength, followed by water content, magnesium slag content, and curing period successively. The 7 d compressive strength of mixtures with different mixing ratios meets the strength requirements of the base and subbase of different highway grades, and all mixtures show good water stability. The test road also achieves good performance. These findings prove that using cement-stabilized magnesium slag- Aeolian sand mixture as the pavement base and subbase materials is feasible. The magnesium slag content should be higher than 45% under 5% cement content to meet the strength requirements base. This study can provide references to the applications of magnesium slag and Aeolian sand in semi-rigid base materials.

The MGS1 segment of the Milanggouwan stratigraphic section, which is located on the southeastern margin of the Mu Us Desert in China, recorded 11 sedimentary cycles consisting of aeolian dune sands overlapping with fluvio-lacustrine facies or paleosols in the Holocene. Through the analysis of trace elements, gastropods, and sporopollen fossils in some layers of the MGS1, this study presents the monsoon climate fluctuations on the millennial-scale in the Mu Us Desert during the Holocene. The results show that the contents of trace elements (P, Pb, Rb, Nb, Zr, V, Sr, Cu, Ni, As, B a, and Co) have similar distribution characteristic, their contents are low in the dune sands but are relatively high in the overlying fluvio-lacustrine facies or paleosols showing 11 cycles in alternation of valleys and peaks. The trace elements in the paleo-mobile dune sands of MGS1 are quite consistent with those of modern mobile dune sands in Salawusu River Valley; therefore, paleo-mobile dune sands can be assumed to be a result of the main periods of the prevalence of East Asian winter monsoon. The increased element contents in the overlying fluvio-lacustrine facies or paleosols are mainly due to the prevailing East Asian summer monsoon. In addition, the 11 elements' cycles represent the climate changes on the millennial-scale in the alternation of East Asian winter and summer monsoons in the Holocene. The paleoecology indicated by gastropods and sporopollen fossils reflects the warm and humid sparse forest grassland environment prevailing in the East Asian summer monsoon when the fluvio-lacustrine facies were deposited; the sporopollen is missing in the dune sands, presumably, it might be dry and windy sandy desert then. The dominant periods of the winter monsoon in these cycles, in terms of time and nature of the climate, could correspond to the cold events in the North Atlantic and lakes, loess, peat and stalagmites in China. It probably indicates that the millennial-scale environmental changes in China's desert regions may be caused by the changes of solar radiation and the increase in ice volume in the Northern Hemisphere during the Holocene.

At present, the coastal sandy soil in special region of Yogyakarta has developed to be a potential agricultural field. Salinity has become one main obstacle in this specific field. The research aimed to examine the growth and yield responses of three rice cultivars in several salinity levels in this coastal sandy soil. The research was carried out in Srigading and Baros Villages, Bantul District of Yogyakarta Special Region, Indonesia. A split plot design was applied, with salinity levels (0.1; 1.0 and 2.5) dS.m(-1) as main plot and rice varieties (IR 64, Situbagendit and Dendang) as sub plot. The treatments were replicated three times. The results showed that there was hardly significant difference in most of the growth and yield variables in IR 64 and Situbagendit. However, at 2.5 dS.m(-1) Dendang (the salt resistant rice) performed the highest chlorophyll content. With salinity up to 2.5 dS.m(-1), there was an increase in stomatal conductance, shoot dry biomass and grain yield. Overall, adding salinity up to 2.5 dS. m(-1) in coastal sandy soil promoted better growth and yield of rice. However, with higher salinity levels, grain yields decreased. The decrease in grain yield was larger in salt resistant variety, than in salt sensitive varieties.

The paper presents the results of the subsurface irrigation experimental research at grain sorghum. The experiment was located on a sandy soil plot, in the arid Dabuleni region of southern Romania, under the climatic condition of 2020. Two variants of subsurface drip irrigation were placed: at a depth of 20 cm and at a depth of 40 cm. Observations and determinations were made regarding the soil humidity on the profile of 0-20 cm, 20-40 cm and 40-60 cm. Hydro physical indices (momentary water supply, the soil water reserve and the soil water deficit) were calculated to establish the irrigation norms according to the water consumption of the grain sorghum. The analysis of the results obtained for sorghum cultivation highlighted better use of subsurface irrigation with the location of drip lines at 40 cm depth, the level of grain production being 5758.3 kg center dot ha(-1), with a difference of 1182.3 kg center dot ha(-1), distinctly significant from the irrigation located at 20 cm depth. Using this method, the water is distributed in the area of root development and ensures optimal humidity in the soil for a longer period, with no losses, compared to the burial variant of the drip lines at 20 cm, when a significant part of the water that rises in the soil layer to the surface, through the capillary ascent, is lost by evaporation.