Water Capacity Research Articles

Vertical Shaft Kinetic Turbine Performance Using A Cup-Shape Blade

The abundant availability of alternative energy sources forms the fundamental foundation for rural energy development. In particular, renewable energy sources are indispensable in rural areas due to their eco-friendly nature and widespread accessibility, which helps preserve the environment by avoiding pollution. Indonesia, a country blessed with vast water resources, especially its rivers, holds enormous potential for harnessing kinetic energy derived from fast-flowing river waters. Effective utilization of this kinetic energy has the potential to address energy shortages in the country. In this context, there is a pressing need to enhance the efficiency of kinetic turbines designed to function as electricity generators in rural regions. This study focuses on evaluating the impact of variables such as the guide angle, water flow speed, and turbine rotation on turbine power and efficiency. The study employs an experimental approach to achieve its objectives, involving tests to assess the performance of a vertical shaft kinetic turbine equipped with bowl blades. Data analysis based on the experimental findings enables the determination of both turbine power and efficiency. The study outcomes demonstrate that the bowl blade type turbine outperforms the curved blade type, primarily due to its larger water capacity, which significantly exceeds that of the curved blade variant. This study emphasizes the potential for harnessing kinetic energy efficiently in rural areas to support sustainable energy development.

Effects of Land Use on Soil Physical-Hydric Attributes in Two Watersheds in the Southern Amazon, Brazil

Changes in land use can cause degradation of soil physical quality with negative effects on the environment and agricultural production. The effects of different land uses on soil physical-hydric attributes were studied in the Renato River and Caiabi River watersheds in the southern Brazilian Amazon. Three conditions of land use were evaluated: native forest, crops, and pasture in the headwater, middle, and mouth of each watershed. Particle size, particle density, bulk density, total porosity, macroporosity, microporosity, water contents at field capacity and permanent wilting point, and available water capacity in soil were evaluated in three soil layers down to 0.4 m. Data collected were subjected to the Kruskal–Wallis nonparametric test and Pearson’s correlations. Multivariate analyses were also performed using the principal component method. In the Renato watershed, in comparison with native forest, conventional management of pasture and crops caused soil physical degradation, increasing soil density in the surface layer and reducing macroporosity and total porosity. In the Caiabi watershed, converting native forest areas into pasture and crops altered water quality, influencing the water dynamics in the soil, by reducing soil water conductivity. Soil attributes varied by watershed, with texture variations between the headwater and mouth, indicating that changes in soil properties result from both management and the granulometric composition of the soil in different regions of the same watershed. Adoption of crop and pasture conservation practices can improve soil physical attributes in regions bordering agricultural areas in the southern Amazon.

Application of bio-organic amendments improves soil quality and yield of fennel (Foeniculum vulgare Mill.) plants in saline calcareous soil

The impact of bio-organic amendments on crop production is poorly understood in saline calcareous soils. The aim in the present study was to determine the effects of the application of organic manure along with lactic acid bacteria (LAB) on soil quality, and morpho-physio-biochemical responses, seed yield (SY) and essential oil yield (EOY) of fennel plants (Foeniculum vulgare Mill.) grown in saline calcareous soils. Eight treatments of farmyard manure (FM) or poultry manure (PM) individually or combined with Lactobacillus plantarum (Lp) and/or Lactococcus lactis (Ll) were applied to saline calcareous soil in two growing seasons. Either FM or PM combined with LAB had beneficial effects on lowering ECe, pH and bulk density and increasing total porosity, organic matter, and water and nutrient retention capacities in addition to total bacterial population in the soil. Growth, nutrient uptake, SY and EOY of plants were also enhanced when fennel seeds were inoculated with Lp and/or Ll and the soil was amended with any of the organic manures under unfavorable conditions. Compared to control (no bio-organic amendments), FM + Lp + Lt or PM + Lp + Lt treatment signficantlly (P ≤ 0.05) increased plant height by 86.2 or 65.0%, total chlorophyll by 73 or 50%, proline by 35 or 45%, glutathione by 100 or 138%, SY by 625 or 463% and EOY by 300 or 335%, respectively, in fennel plants. Co-application of the naturally occurring microorganisms (i.e., LAB) and organically-derived, nutrient-rich fertilizer (i.e., FM or PM) is recommended to improve yield of fennel plants in saline calcareous soils.

Soil Properties of Fallow Land Invaded by Black Cherry (Padus serotina (Ehrh.) Borkh.)

The extensive spread of the invasive black cherry, Padus serotina, has been observed on abandoned agricultural land in Central and Eastern Europe. However, the impact of this species on invaded agroecosystems is still unknown, including the possibility of returning these ecosystems to agricultural production. In order to evaluate the selected soil properties of fallows invaded by P. serotina, their texture, field water capacity, reaction, and content of organic carbon, total nitrogen, and available forms of potassium and phosphorus were determined for 100 study plots. Taking into account the influence of soil conditions on floristic composition, the area covered by individual plant species in the study plots was also included in the analysis. A relationship was found between the presence of all the developmental stages of P. serotina and an increase in the phosphorus content in the soil. With the growth of a black cherry shrub layer, the content of soil nitrogen and potassium increased. An increasing proportion of P. serotina in the herb layer contributed to soil acidification and reduced the water content available for plants in the arable layer at 20–40 cm. The possible impact of P. serotina on soil properties may be an additional premise when considering the possibilities and benefits of the recultivation of fallow land invaded by this species.

Can We Predict Available Water Capacity from Long‐Term Soil Moisture Data?

Can We Predict Available Water Capacity from Long‐Term Soil Moisture Data?

ChatGPT Research Group for Optimizing the Crystallinity of MOFs and COFs.

We leveraged the power of ChatGPT and Bayesian optimization in the development of a multi-AI-driven system, backed by seven large language model-based assistants and equipped with machine learning algorithms, that seamlessly orchestrates a multitude of research aspects in a chemistry laboratory (termed the ChatGPT Research Group). Our approach accelerated the discovery of optimal microwave synthesis conditions, enhancing the crystallinity of MOF-321, MOF-322, and COF-323 and achieving the desired porosity and water capacity. In this system, human researchers gained assistance from these diverse AI collaborators, each with a unique role within the laboratory environment, spanning strategy planning, literature search, coding, robotic operation, labware design, safety inspection, and data analysis. Such a comprehensive approach enables a single researcher working in concert with AI to achieve productivity levels analogous to those of an entire traditional scientific team. Furthermore, by reducing human biases in screening experimental conditions and deftly balancing the exploration and exploitation of synthesis parameters, our Bayesian search approach precisely zeroed in on optimal synthesis conditions from a pool of 6 million within a significantly shortened time scale. This work serves as a compelling proof of concept for an AI-driven revolution in the chemistry laboratory, painting a future where AI becomes an efficient collaborator, liberating us from routine tasks to focus on pushing the boundaries of innovation.

Estimating pre-compression stress in agricultural Soils: Integrating spectral indices and soil properties through machine learning

Soil compaction resulting from heavy machinery use in agricultural and forestry operations poses a significant threat to sustainable agriculture. Advancements in remote sensing technology have enabled the acquisition of vegetation, water, and soil spectral indices, which offer valuable insights into soil properties. This study focuses on estimating the pre-compression stress (Pc) by developing pedotransfer functions (PTFs) using Sentinel-2 satellite-derived spectral indices and soil properties (clay, CaCo3, and bulk density) as inputs. Two machine learning methods, Random Forest (RF) and Boosted Regression Tree (BRT), are employed for the estimation. A total of 140 surface soil samples were collected randomly from agricultural areas in Qazvin province, Iran. The results indicate that the BRT method outperforms the RF method in terms of accuracy. The estimation of Pc achieved better results when the Redness Index (RI) was used as the soil spectral index and the Surface Water Capacity Index (SWCI) was employed as the water spectral index, along with the soil properties as inputs for PTF3 and PTF11. In the training and testing steps, the root mean square error (RMSE) decreased from 0.100 and 0.114 (kPa) in PTF1 to 0.071 and 0.098 in PTF3, and 0.072 and 0.097 in PTF11, respectively. These outcomes demonstrate the practical applicability of estimating Pc through the integration of soil properties and spectral indices. The findings highlight the potential of remote sensing technologies, such as spectral indices, as effective and cost-efficient tools for studying soil compaction. The proposed methodology contributes to our understanding of soil compaction processes and provides valuable insights for developing sustainable land management strategies. This study has implications for the agricultural sector and offers practical solutions to mitigate soil compaction and its detrimental effects on agricultural productivity.

Rancang Bangun Pompa Air Aliran Aksial Pipa Pvc 5 Inci Berpenggerak Motor Listrik

<p><em>Axial pumps are one type of pump that is widely used for industrial purposes to move fluids from low places to higher places with large capacities. The axial pump has very complicated components so it has a very expensive price. This study aims to design and build an axial flow pump with a 5-inch PVC pipe casing driven by an electric motor. The design process begins with the determination of pump specifications including the capacity of the fluid you want to flow and the height of the fluid you want to move, then proceed with calculations including the capacity of the electric motor, shaft, and bearings, then proceed with the process of making components according to the calculations that have been done and the final stage is the process assembly and testing. The result of the calculation is that for an axial pump specification with a maximum head of 0.5 m, a pipe diameter of 0.14 m, and a maximum capacity of fluid that can flow 0.02 m3/s, a ½ Hp motor is required with a drive shaft diameter of 10 mm. The test results show that the pump can operate properly, the water capacity that can be moved is 0.0138 m3/s for the variation in the number of blades 2 and 0.0161 m3/s for the variation in the number of blades 3. So the efficiency for the variation in the number of blades 2 is 46.54% and for blade 3 is 54.53%</em></p>

Climate and breeding determined below-ground biomass allocation strategy in wheat

Farmland covers about 12% of the ice-free terrestrial surface, and crop below-ground biomass allocation plays a pivotal role in the sequestration of atmospheric carbon. Nevertheless, our understanding of the integrated response of crop belowground biomass allocation strategy to concomitant variation in key environmental factors related to water and nutrient availability remains limited. Furthermore, it is imperative to conduct further analysis to elucidate the influence of breeding efforts geared toward improving crop yield on the below-ground biomass allocation strategy. Here we compiled a global wheat root mass fraction (RMF) database with 221 observations from 39 studies to analyze the integrated response of RMF to climate, soil properties and filed managements, and the relationship of RMF and yield. We identified an aridity index (AI) threshold of 0.44 for wheat below-ground biomass allocation strategy, based on the effect of long-term climate on plow-layer soil organic carbon and field water capacity (FWC). The negative effect of nitrogen fertilizer rate on RMF along the AI gradient did not significantly change but the main mechanism shifted from indirect to direct effects. For AI < 0.44, the response of RMF to change of water availability was relatively conservative with the insignificant effects of FWC on RMF. However, RMF was highly sensitive to precipitation distribution during the growth stage because RMF decreased as the ratio of precipitation during the reproductive stage to the growth stage increased. We did not observe a significant correlation between RMF and yield within the main range of RMF so a large amount of intraspecific variation in belowground biomass allocation strategies had not been filtered out by breeding. For AI ≥ 0.44, RMF was highly sensitive to water resource availability as RMF significantly decreased with an increase in FWC. Yield decreased significantly with increasing RMF within the main range of RMF, resulting in highly consistent intraspecific belowground biomass allocation strategies under the pressure of breeding. The results suggested long-term climate condition and breeding played critical filters in wheat below-ground biomass allocation strategy and provided a more accurate prediction of RMF for global carbon cycle models and crop growth models.

Predicting urban carrying capacity to support sustainable tourism using GIS

ABSTRACT This paper aims to quantifying urban carrying capacity prediction to support sustainable tourism industry in the Urban Area of Labuan Bajo Flores. This study uses the superimpose method with weighted overlay in spatial modeling to analyze land, water, electricity, settlements, and waste carrying capacity. In 2042, it is expected that three of the five carrying capacity variables will experience a deficit. The deficiency variables are the availability of land, electricity, and water. In addition, these conditions are assessed through spatial distribution using GIS, which identifies four regions in the Labuan Bajo urban area that fall under the category of high-priority treatment. Based on these findings, Labuan Bajo must prioritize sustainability so that the spatial planning and allocation of resources are cognizant of carrying capacity in order to realize sustainable development of urban area with main activity is tourism industry, particularly in the urban area of Labuan Bajo.

Nutritional content, amino acid profile, and protein properties of edible insects (Tenebrio molitor and Gryllus assimilis) powders at different stages of development

Insects have great potential as ingredients for industrial purposes, providing good technological properties. This study aimed to characterize powders of Tenebrio molitor and Gryllus assimilis at two developmental stages for potential use in human nutrition. The insect powders were analyzed for their proximate composition, mineral content, carotenoids, vitamins C and E, riboflavin, niacin, amino acid profile, in vitro protein digestibility, solubility as a function of pH, foam-forming, and water and oil-holding capacity. Both powders were excellent sources of proteins (ranging from 57.36 % to 67.97 %), phosphorus (512.00–732 mg/100 g), copper (1.45–3.01 mg/100 g), iron (5.41–8.41 mg/100 g), zinc (11.62–25.57 mg/100 g), manganese (1.63–8.08 mg/100 g), good sources of magnesium (84.00–180.00 mg/100 g), and sources of potassium (624.00–820.00 mg/100 g), and niacin (1.88–3.21 mg/100 g). The proteins showed good digestibility (84.48–92.53 %) and increased solubility in alkaline pH (∼11). Lysine was identified as the limiting amino acid for both species analyzed (EAAS: 0.55–0.79). The development stage of the insects influenced their nutritional content, amino acid profile, and functional protein properties. The data obtained support the potential use of these insect powders on a large scale and contribute to selecting the development stage with the best nutritional composition.

Grain carbon isotopes indicate the ability of wheat plants to maintain enhanced intrinsic water-use efficiency even after short-term exposure to high temperatures and drought

Minimizing the impact of heat and drought on crop yields requires varieties with effective protective mechanisms. We tested the hypothesis that even a short-term high temperature amplifies the negative effects of reduced water availability on leaf gas-exchange, but can induce long-lasting improvement in plant water-use efficiency after the stress period. Accordingly, three common varieties of winter wheat (Triticum aestivum) were grown under field conditions. During the stem extension, the plants were exposed to distinct temperatures (daily maximum 26 vs. 38 °C), water availabilities (75% of field water capacity vs. permanent wilting point), and their combination for 14 days.All treatments reduced light-saturated rates of CO2 assimilation and transpiration, particularly when heat and drought were combined. Drought enhanced water-use efficiency (WUE) in all varieties (31.4–36.4%), but not at high temperatures (decrease by 17–52%). Intrinsic WUE (iWUE), determined from the stable carbon isotope composition of grains, was enhanced by 7.9–37% in all treatments and varieties; however, not all changes were significant. The combination of heat and drought tended to increase total protein content in grains but reduced spike productivity. Noticeably, the strongest decline in spike productivity was observed in Elan – the variety displaying the smallest enhancement of iWUE, while it was negligible in Pannonia which shows the most pronounced improvement of iWUE. We conclude that even several hot and dry days can improve iWUE for the rest of the vegetation season. This improvement, however, does not necessarily lead to increased crop productivity possibly due to physiological trade-offs.

Land suitability assessment for wheat-barley cultivation in a semi-arid region of Eastern Anatolia in Turkey.

The efficient use and sustainability of agricultural lands depend heavily on the characteristics of soil resources in a given area, as different soil properties can significantly impact crop growth and yield. Therefore, land suitability studies play a crucial role in determining the appropriate crops for a given area and ensuring sustainable agricultural practices. This study, conducted in Tusba District-Van, Turkey, represents a significant advancement in land suitability studies for wheat-barley cultivation. Using geographic information systems, the analytical hierarchical process method, and the standard scoring function, lands were determined based on the examined criteria for the suitability of wheat-barley cultivation. One of this study's main findings is identifying critical factors that influence the suitability of land for wheat-barley cultivation. These factors include slope, organic matter content, available water capacity, soil depth, cation exchange capacity, pH level, and clay content. It is important to note that slope is the most influential factor, followed by organic matter content and available water capacity. A Soil Quality Index map was produced, and the suitability of wheat-barley production in the studied area was demonstrated. More than 28% of the study area was very suitable for wheat-barley production (S2), and more than was 39% moderately suitable (S3). A positive regression (R2=0.67) was found between soil quality index values and crop yield. The relationship between soil quality index values and crop yield is above acceptable limits. Land suitability assessment can minimize labor and cost losses in the planning and implementation of sustainable ecological and economic agriculture. Furthermore, land suitability classes play an active role in the selection of the product pattern of the area by presenting a spatial decision support system.

Soil water infiltration characteristics of reforested areas in the paleo-periglacial eastern Liaoning mountainous regions, China

Plantation forests (PF) and natural secondary forests (NSF) are the primary reforestation approaches. The establishment of PF can affect forest hydrological processes by changing soil structure. To date, few studies have focused on these changes and the effects on hydrological processes for the paleo-periglacial landform. To reveal reforestation approaches effects on water infiltration, including soil water infiltration capacity, retention capacity, and waterflow path pattern, we conducted field dye-tracer investigations with rainfall and laboratory infiltration experiments for the paleo-periglacial landform of eastern Liaoning mountains, China. The results showed that (1) Soil physical properties (including total porosity (TP), capillary porosity (CP), non-capillary porosity (NCP), initial soil water content (IWC), field water capacity (FWC)) and root abundance (RA) decreased with soil depth in both PF and NSF, while the soil bulk density (BD) and distribution of gravel content showed opposite changes. (2) Establishment of PF reduced the infiltration capacity and water retention capacity in the 0–20 cm layer, but enhanced the water retention capacity in 20–30 cm layer. Low IWC was conducive to increase soil water content (SWC) after infiltration. (3) Infiltration capacity parameters (including saturated hydraulic conductivity (Ks), SWC, difference between SWC and IWC (SWC–IWC), dye coverage ratio (DC)) were significantly correlated with BD, TP, CP, NCP, FWC, and fine roots RA (P < 0.05). Better connectivity gravels were more conducive to water infiltration. (4) Preferential flow was the main infiltration type, but with different waterflow paths pattern, with the 'funnel', 'finger' shape for PF, NSF, respectively. Increasing infiltration could increase flow path connectivity. Our findings show that soil physical properties, roots, and gravel occurrence affected soil infiltration, and different reforestation approaches had varying impacts on soil infiltration, water redistribution, transportation, and storage of surface and groundwater, improving the understanding of ecohydrological processes and effects of water resources management in forest ecosystems of paleo-periglacial landform.

Alternative uses for crushed stone products generated to meet the raw material needs of asphalt production in Hungary

In Hungary, quarries that produce stone products for wearing courses of asphalt pavements also produce a significant amount of 0/4, 0/8 and 4/8 mm fractions. Because of Hungary’s pavement design and asphalt production practices, these fractions do not have a suitable market and can thus be sold on alternative markets. Purpose. To demonstrate the feasibility of using crushed fractions of 0/4 and 0/8 mm in the protection and base layers of asphalt pavements instead of sandy gravel with 0/22 mm fraction. Methodology. The CBR method was applied to evaluate the comparability of characteristics such as particle size distribution and load-bearing capacity. The combination of the Proctor and CBR tests allowed someone to compare the expected technological characteristics of the dominant and alternative aggregate types, such as their sensitivity to water and load-bearing capacity. Findings. The results demonstrated that the performance characteristics of conventionally used sandy gravel with a size of 0/22 mm can be achieved and exceeded by crushed material with much smaller maximum grain sizes – i.e., 0/4 and 0/8 mm. Originality. The paper presents an original study that contradicts the industry’s actual decline of crushed stone (0/4 and 0/8 mm fractions) for asphalt pavement protection layers. The potential effectiveness and functionality of the proposed coating are demonstrated through convincing tests, and thus new data and insights are introduced into the Hungarian construction industry’s practice. Practical value. The test results greatly helped in achieving the high demands of the private industrial project by proposing an alternative variant of crushed stone of 0/8 mm fraction rather than the originally planned dominant sand and gravel material. The asphalt paving experience on this site clearly demonstrated the viability of the alternative aggregate option for Hungarian roads.

PSV-3 Evaluation of Functional Properties of Chitin as a Novel Non-Meat Ingredient for Manufacturing Meat Emulsions

Abstract There has been a growing demand for developing naturally occurring non-meat ingredients, which could replace or reduce synthetic additives that have been used extensively in manufacturing processed meat products. Chitin, which is a major component of crustacean shells and a precursor of chitosan, is the second most abundant polysaccharide followed by cellulose. While some functional properties of chitin such as water/fat binding capacity and emulsifying ability have been reported, there are almost little to no studies determining the efficacy of chitin as a non-meat ingredient. The objective of this study was to evaluate the functional properties of chitins as a novel non-meat ingredient for manufacturing emulsified sausages. Fresh pork hind leg and pork back fat from 9 carcasses at 4 d postmortem were obtained. The trimmed pork hind legs were randomly assigned into three independent batches for emulsion and sausage production. Chitins were extracted from chitin-like material (CLM) from two different crustacean shell sources, such as crawfish (CF) and blue crab (BC). The CLM were extracted and used in the following order: drying-deproteinization (1% calcium oxide)-demineralization (2N HCl)-deacetylation (6M NaOH). For the emulsion and sausage manufacturing, control was prepared with 70% raw meat, 18% backfat, 10% water, 1.5% sodium chloride and 0.5% sodium phosphate. The treatments were prepared with 70% raw meat, 18% backfat, 10% water, 1.5% sodium chloride, 0.2% phosphate, and 0.5% CLM. The functional properties of CLM were evaluated by measuring binding capacity, emulsion capacity, and color attributes. For the evaluation of meat batter and emulsified sausage products, instrumental color, texture profile analysis, emulsion stability, cooking loss, and pH were measured. The data analysis was conducted by mixed model, and least squares means for all traits were separated (F-test, P &amp;lt; 0.05) by using least significant differences. No significant difference in the color attributes of meat batter between the control and the treatments (CF and BC) was found. The chitin added products from both CF and BC had a greater emulsion stability, where the treatment showed about two time greater in emulsion stability compared with control (P &amp;lt; 0.05). In particular, chitin extracted from CF showed greater water and fat binding capacity than CB (P &amp;lt; 0.05). In the emulsified sausage, the treatments showed significantly greater redness and hardness than control (P &amp;lt; 0.05). In particular, the CF showed greater cohesiveness and gumminess than control or BC (P &amp;lt; 0.05). The results of the present study showed the beneficial impacts of chitin addition for meat emulsions. The chitin inclusion improved the quality characteristics of emulsified sausage such as textural properties and emulsion stability, while less amount of phosphate was added compared with control. Additionally, chitin from crawfish had superior functional properties to that from blue crab, indicating different chitin functionality between crustacean shell sources.

Utilization and Applications of Chitosan Extracted from Solenocera crassicornis Exoskeleton

In marine arthropods, the largest group Crustaceans contains 30,000 species. The shells of marine crustaceans such as shrimp, crab, and lobster, contribute to pollution in coastal areas as biowaste. The crustacean shell wastes consist of approximately 8-10 % chitin, 30-65 % protein, and 10-20 % calcium. Chitosan, a natural biodegradable polymer derived from chitin, finds applications in various fields. In the present paper, the chitosan was extracted from Solenocera crassicornis shrimp shells through a three-step process, which includes demineralization, deproteinization, and deacetylation. The physicochemical properties of chitosan including ash, moisture content, degree of deacetylation, water and fat binding capacity, and solubility were analyzed. This study explored the diverse applications of chitosan, including its antimicrobial, shelf-life enhancement, anticoagulant, and wastewater treatment properties. This study concluded that chitosan can be suitable for application in various fields including medicine, cosmetology, biotechnology, the edible film industry, and water purification.

Impact of Cover Cropping on Temporal Nutrient Distribution and Availability in the Soil

Cover cropping is a best management practice that can improve soil quality by reducing soil erosion, building soil organic matter (SOM), and improving soil nutrient availability. Southwest (SW) Florida citrus growers have the challenge of growing citrus in sandy soils characterized by low organic matter (&lt;2%), extremely low water and nutrient-holding capacities, and high sand content (&gt;90%), and therefore are looking for methods to improve SOM and nutrient retention and availability in sandy soils. A trial of two cover crop (CC) mixtures planted in the row middles (RM) of Huanglongbing-affected citrus ‘Valencia’ (Citrus sinensis (L.) Osbeck) orchards in sandy soils in SW Florida was conducted. This study explored how incorporating CCs in the RM of the orchards could affect soil ammonium (NH4+), soil nitrate (NO3−), exchangeable macronutrients, and SOM temporal availability. These parameters were measured under the tree canopy (UC) and within RM of two orchards: South Grove (SG) and North Grove (NG), both located in SW Florida. The two seeded CC mixtures were legume + non-legume (LG+NL) and non-legume (NL) and were compared to a control no-CC grower standard (GSC). Phosphorus, calcium, magnesium, and NH4+ were not statistically significantly different among treatments in either of the two sampling positions (UC and RM). Cover cropping significantly (p &lt; 0.05) increased NO3−-N concentrations in the RM area of the citrus orchards after seven consecutive seasons (brassicas, legumes, and grasses) by 31% in the LG + NL and 29% in the NL with reference to the GSC. In addition to the significant increase in NO3−N, SOM significantly (p &lt; 0.05) increased in the RM in the NG site only in both CCs treatments by 17% and 16% for LG + NL and NL treatments, respectively, compared with GSC.

Assessing the effects of agricultural waste returning on soil moisture characteristics

AbstractAgricultural waste is an emerging and promising resource due to its abundant organic compounds and high water‐holding capacity. It plays a crucial role in improving soil water use efficiency and contributing to sustainable agricultural development. This study aimed to investigate the impact of returning agricultural waste on soil moisture characteristics. Different volume ratios (4:5:1:0, 3:5:1:1, 2:5:1:2, 1:5:1:3, and 0:5:1:4) of agricultural waste blend (AWB) consisting of cattle manure, yellow loam soil, wheat straw, and distiller's grains were examined, and the water‐holding performance of the five AWB ratios under various suction forces was compared. The analysis confirmed the suitability of the Van Genuchten‐Mualem model for fitting soil moisture characteristic curves at different ratios. The study also examined the influences of AWB ratios on soil‐specific water capacity, hydraulic parameters, and equivalent pore size. The results showed that agricultural waste effectively increased soil‐specific water capacity, available water content, soil WHC(Water‐holding capacity), and soil pore count. Furthermore, reducing cattle manure and increasing distiller's grains enhanced these effects. For instance, when the AWB ratio was 0:5:1:4, soil‐specific water capacity increased by 47.7%, while field WHC and available water content increased by 9.9% and 3.8%, respectively. Additionally, the number of extremely small and small pores increased by 1.4% and 0.77%, respectively. These findings provide valuable theoretical guidance for agricultural waste treatment and improving soil WHC. Based on the results, it is recommended to increase the proportion of distiller's grains and reduce organic fertilizer when using agricultural waste for improving soil WHC.

Irrigation Salinity Affects Water Infiltration and Hydraulic Parameters of Red Soil

Unconventional water resources (e.g., saline water, etc.) for irrigation as a promising supplementary water source can alleviate the freshwater shortage in the agriculture of red soil areas in Southern China. It should be noted that the presence of soluble salt in this water source may have detrimental influences on soil water infiltration and crop growth. Understanding the effect of unconventional water irrigation (UWI) on water infiltration in red soil is important. Previous studies have shown that the salinity of UWI can alter soil hydraulic properties to change soil water movement in saline soils. However, the underlying mechanism and factors of water infiltration in red soil under UWI with different salinity levels remain limited. Therefore, a laboratory experiment (one-dimensional vertical infiltration experiment and centrifuge method) was conducted to evaluate the effect of UWI with different salinity levels [0 (the distilled water, CK), 1 (S1), 2 (S2), 3 (S3), 5 (S5), and 10 (S10) g L−1] on the soil water infiltration process, soil water characteristic curve (SWCC), soil water constants estimated using the SWCC, saturated and unsaturated hydraulic conductivity (KS and K) as well as the soil chemistry of soil profile [pH, electrical conductivity (EC), and Na+ and Cl− contents]. The primary factors of soil water infiltration were identified using stepwise regression and path analysis methods. The results showed that UWI salinity decreased water infiltration by 1.53–7.99% at the end of infiltration in red soil, following the order of CK &gt; S1 &gt; S5 &gt; S2 &gt; S3 &gt; S10. Moreover, UWI could enhance soil water availability with an increase of 8.55–12.68% in available water capacity. In contrast, lower KS and K were observed in S1–S10, and there was a negative linear relationship between irrigation salinity and KS. UWI also produced the EC, Na+, and Cl− accumulations in the soil profile. As the salinity level of UWI increased, the accumulations aggravated. Soil acidification was found in S1–S5, while soil alkalization was observed in S10. Additionally, α, PWP, and KS were the primary factors influencing the water infiltration of red soil. This study can help optimize the soil infiltration model under UWI and establish a foundation for unconventional water management in the red soil regions of Southern China and other similar regions. In addition, the undisturbed red soil under agricultural unconventional water irrigation and the long-term effect of unconventional water application should be considered.