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High‐Resolution 3‐D Mapping of Soil Texture in Denmark
by
Greve, Mette B.
,
McBratney, Alex B.
,
Bøcher, Peder K.
in
agricultural mechanization
,
Clay
,
Clay (material)
2013
Soil texture which is spatially variable in nature, is an important soil physical property that governs most physical, chemical, biological, and hydrological processes in soils. Detailed information on soil texture variability both in vertical and lateral dimensions is crucial for proper crop and land management and environmental studies, especially in Denmark where mechanized agriculture covers two thirds of the land area. We modeled the continuous depth function of texture distribution from 1958 Danish soil profiles (up to a 2‐m depth) using equal‐area quadratic splines and predicted clay, silt, fine sand, and coarse sand content at six standard soil depths of GlobalSoilMap project (0–5, 5–15, 15–30, 30–60, 60–100, and 100–200 cm) via regression rules using the Cubist data mining tool. Seventeen environmental variables were used as predictors and their strength of prediction was also calculated. For example, in the prediction of silt content at 0 to 5 cm depth, factors that registered a higher level of importance included the soil map scored (90%), landscape types (54%), and landuse (27%), while factors with lower scores were direct insolation (17%) and slope aspect (14%). Model validation (20% of the data selected randomly) showed a higher prediction performance in the upper depth intervals but increasing prediction error in the lower depth intervals (e.g., R2 = 0.54, RMSE = 33.7 g kg−1 for silt 0–5 cm and R2 = 0.29, RMSE = 38.8 g kg−1 from 100–200 cm). Danish soils have a high sand content (mean values for clay, silt, fine sand, and coarse sand content for 0‐ to 5‐cm depth were 79, 84, 324, and 316 g kg−1, respectively). Northern parts of the country have a higher content of fine sand compared to the rest of the study area, whereas in the western part of the country there was little clay but a high coarse sand content at all soil depths. The eastern and central parts of the country are rich in clay, but due to leaching, surface soils are clay eluviated with subsequent accumulation at lower depths. We found equal‐area quadratic splines and regression rules to be promising tools for soil profile harmonization and spatial prediction of texture properties at national extentacross Denmark.
Journal Article
Effect of Soil Texture on Soil Nutrient Status and Rice Nutrient Absorption in Paddy Soils
2024
Soil texture affects rice nutrient uptake and yield formation by influencing soil structure, microbial activity, and soil nutrient supply capacity. Analyzing the relationship between soil texture, nutrient content, and rice agronomic traits is of great significance for precise and efficient fertilizer application. The tillage layer (0–20 cm) of 31 paddy fields in China’s main rice-producing areas was collected to perform rice pot experiments, and soil texture characteristics, physicochemical properties, microbial-related indicators, and rice agronomic traits were measured and analyzed. The results showed that these soils could be classified into four types of soil texture: loamy sandy soil, sandy loam soil, silty loam soil, and silty soil. Analysis of variance showed that the available nitrogen (AN), available potassium (AK), and available phosphorus (AP) contents were the highest in silty loam, silty, and sandy loam soils, respectively, and silt loamy soil had the highest CEC. Principal component analysis (PCA) also showed that soil physicochemical properties can be distinguished to a certain extent according to soil texture types. For the relationship of soil texture parameters and soil physicochemical properties, soil organic matter (OM), total nitrogen (TN), AN, ammonium nitrogen (NH4+-N), and microbial carbon (MBC) contents were positively correlated with soil clay content, AK was positively correlated with silt content, and soil phosphorus status was significantly related to pH. Mantel’s test revealed significant correlations between rice N, P, and K nutrient status, dry matter accumulation, and yield, and soil available nutrient content, MBC, pH, and soil texture parameters. Structural equation modeling (SEM) indicated that sand affected soil available nutrients by regulating pH, while clay can positively influence soil available nutrients by affecting soil organic matter mineralization and microbial activity, thus influencing nutrient absorption and yield formation in rice. Overall, in rice production, the silty and silty loam paddy soil with fine texture and higher clay content facilitates the mineralization of soil organic matter and the activity of soil microbes, resulting in more available soil nutrients, which benefits the rice absorption and accumulation of nutrients. Furthermore, a higher content of clay also promotes the distribution of dry matter to the panicle, thereby promoting rice yield formation.
Journal Article
Silting Process and Loss of IPosidonia oceanica/I Meadows in the Tyrrhenian Waters of Calabria
2023
In the Mediterranean Sea, two critical issues affect marine benthic biocenosis: sedimentation and the increasing trend in marine biodiversity loss. These processes are very marked along the western side of the Calabrian coastline, where siltation is one of the main reasons for the regression of Posidonia beds in the regional coastal waters. This study investigates the relationships between the geomorphological features of the debris source areas, represented by fluvial basins, and the distribution of Posidonia meadows. So, a concise geomorphological study of the Tyrrhenian fluvial basins with an area greater than 200 km[sup.2] was carried out, and we correlated the results with the mapping of the meadows in Calabria’s Tyrrhenian waters. Furthermore, to assess the increased level of burial in a Posidonia oceanica meadow and its health state over time, a program of Posidonia monitoring was undertaken between 2000 and 2010 in a test area located in the Marine Regional Park of Isca (Calabria, Southern Italy). The results of this survey highlighted that, at the beginning of the study period, the silting rate of 4–5 cm/year saw the meadow suffer a reduction in its photosynthetic ratio with a mortality rate of 50%. The siltation rate reached 12 cm/year in 2010, and the meadow began to disappear. Therefore, marine pollution via sedimentation represents a serious factor in the regression of Posidonia oceanica meadows and enhances the risk of a gradual loss of marine biodiversity.
Journal Article
High soil moisture rather than drying-rewetting cycles reduces the effectiveness of nitrification inhibitors in mitigating N2O emissions
by
Mühling, Karl Hermann
,
Ribeiro, Pablo Lacerda
,
Naeem, Asif
in
Bacteria
,
Biodegradation
,
Climate change
2024
Climate change has been intensifying soil drying and rewetting cycles, which can alter the soil microbiome structure and activity. Here we hypothesized that a soil drying-rewetting cycle enhances biodegradation and, hence, decreases the effectiveness of nitrification inhibitors (NIs). The effectiveness of DMPP (3,4-Dimethylpyrazole phosphate) and MP + TZ (3-Methylpyrazol and Triazol) was evaluated in 60-day incubation studies under a drying and rewetting cycle relative to constant low and high soil moisture conditions (40% and 80% water-holding capacity, WHC, respectively) in two different textured soils. The measurements included (i) daily and cumulative N2O-N emissions, (ii) soil NH4+-N and NO3−-N concentrations, and (iii) the composition of bacterial soil communities. Application of DMPP and MP + TZ reduced the overall N2O-N emissions under drying-rewetting (-45%), as well as under 40% WHC (-39%) and 80% WHC (-25%). DMPP retarded nitrification and decreased N2O-N release from the sandy and silt loam soils, while MP + TZ mitigated N2O-N production only from the silt loam soil. Unexpectedly, between days 30 and 60, N2O-N emissions from NI-treated soils increased by up to fivefold relative to the No-NI treatment in the silt loam soil at 80% WHC. Likewise, the relative abundance of the studied nitrifying bacteria indicated that the NIs had only short-term effectiveness in the silt loam soil. These results suggested that DMPP and MP + TZ might trigger high N2O-N release from fine-textured soil with constant high moisture after this short-term inhibitory effect. In conclusion, DMPP and MP + TZ effectively reduce N2O-N emissions under soil drying and rewetting.
Journal Article
Impact of root hairs on microscale soil physical properties in the field
2022
Aims
Recent laboratory studies revealed that root hairs may alter soil physical behaviour, influencing soil porosity and water retention on the small scale. However, the results are not consistent, and it is not known if structural changes at the small-scale have impacts at larger scales. Therefore, we evaluated the potential effects of root hairs on soil hydro-mechanical properties in the field using rhizosphere-scale physical measurements.
Methods
Changes in soil water retention properties as well as mechanical and hydraulic characteristics were monitored in both silt loam and sandy loam soils. Measurements were taken from plant establishment to harvesting in field trials, comparing three barley genotypes representing distinct phenotypic categories in relation to root hair length. Soil hardness and elasticity were measured using a 3-mm-diameter spherical indenter, while water sorptivity and repellency were measured using a miniaturized infiltrometer with a 0.4-mm tip radius.
Results
Over the growing season, plants induced changes in the soil water retention properties, with the plant available water increasing by 21%. Both soil hardness (
P
= 0.031) and elasticity (
P
= 0.048) decreased significantly in the presence of root hairs in silt loam soil, by 50% and 36%, respectively. Root hairs also led to significantly smaller water repellency (
P
= 0.007) in sandy loam soil vegetated with the hairy genotype (-49%) compared to the hairless mutant.
Conclusions
Breeding of cash crops for improved soil conditions could be achieved by selecting root phenotypes that ameliorate soil physical properties and therefore contribute to increased soil health.
Journal Article
Improvement of nutritional quality of food crops with fertilizer: a global meta-analysis
2023
Providing the world’s population with sufficient and nutritious food through sustainable food systems is a major challenge of the twenty-first century. Fertilizer use is a major driver of crop yield, but a comprehensive synthesis of the effect of fertilizer on the nutritional quality of food crops is lacking. Here we performed a comprehensive global meta-analysis using 7859 data pairs from 551 field experiment-based articles published between 1972 and 2022, assessing the contribution of fertilization with a wide set of plant nutrients to the nutritional quality of food crops (i.e., fruits, vegetables, cereals, pulses/oil crops, and sugar crops). On average, fertilizer application improved crop yield by 30.9% (CI: 28.2–33.7%) and nutritional quality (referring to all nutritionally relevant components assessed; carbohydrates, proteins, oil, vitamin C, representative mineral nutrients, and total soluble solids) by 11.9% (CI: 10.7–12.1%). The improvements were largely nutrient- and crop species dependent, with vegetables being the most responsive. Potassium, magnesium, and micronutrients played important roles in promoting crop nutritional quality, whereas the combined application of inorganic and organic source(s) had the greatest impact on quality. Desirable climatic conditions and soil properties (i.e., silt loam, soil organic matter 2.5–5.0%, and pH 4.5–8.5) supported further enhancements. Considering cross-continent responsiveness, the increase in the nutritional quality of food crops with fertilizer application was greatest in Africa. In a nutshell, our findings pave the way towards a quantitative understanding of nutrient management programs and responsible plant nutrition solutions that foster the sustainable production of nutritious and healthy food crops for human consumption.
Journal Article
Effect of land and water management on rice yield and water productivity in silty loam soil
by
Khalil, Shahid Hameed
,
Islam, Zafar
,
Akbar, Ghani
in
Agricultural practices
,
Agriculture
,
basins
2025
Aims
To explore efficient and sustainable farming practices in Pakistan by assessing the combined impact of two land management methods and four irrigation techniques on the yield and water productivity of two rice (Oryza sativa) varieties.
Methods
The study evaluated two land management methods (Direct Seeded Rice (DSR) with minimum tillage and Puddled Transplanted Rice (PTR)) and four irrigation techniques (Alternate Wetting and Drying (AWD), Furrow irrigated Narrow Bed (FNB), Drip irrigated Wide Bed (DWB), and Basin Flooding (BF)) using a randomized split-plot design. Green Super Rice 305 (GSR305) was cultivated in 2021, and the Fakhar-e-Malakand (FM) rice variety in 2022, with each treatment replicated three times.
Results
The DSR under raised beds and PTR under flat basins generally exhibited higher yields and better water productivity. Despite a yield trade-off of 26%, DSR with DWB demonstrated 19% higher water productivity than BF. The GSR 305 yielded 141% higher than FM, with the following yield tendencies: PTR with AWD (10.71 t ha
−1
) > PTR with BF (10.16 t ha
−1
) > DSR with FNB (9.18 t ha
−1
) > DSR with DWB (7.56 t ha
−1
). Deep drainage was observed to be 5 to 9 times larger than the crop's water needs, indicating porous soil conditions.
Conclusion
The study underscores the significant potential for improving yield and water productivity in rice farming by carefully implementing optimized land and water management practices coupled with suitable varieties. These findings emphasize the feasibility of transitioning towards less resource-intensive and more sustainable rice cultivation practices in Pakistan.
Journal Article
Impact of different earthworm ecotypes on water stable aggregates and soil water holding capacity
2020
We carried out mesocosm experiments using either the anecic earthworm Lumbricus terrestris or the endogeic earthworm Allolobophora chlorotica and loam, silt loam and sandy loam soils to investigate the differing impact of these earthworm of different ecotypes on aggregate formation (percentage water stable aggregates, %WSA) and soil water holding capacity (WHC), two soil properties that underpin many of the ecosystem services provided by soils. Earthworms significantly increased %WSA (by 16–56% and 19–63% relative to earthworm-free controls for L. terrestris and A. chlorotica, respectively). For L. terrestris, this increase was significantly greater in the upper 6.5 cm of the soil where their casts were more obviously present. Allobophora chlorotica treatments significantly increased WHC by 7–16%. L. terrestris only caused a significant increase in WHC (of 11%) in the upper 6.5 cm of the sandy loam soil. Linear regression indicated a consistent relationship between increases in %WSA and WHC for both earthworm species. However, for a given %WSA, WHC was higher for A. chlorotica than L. terrestris likely due to the known differences in their burrow structure. Overall, earthworms increased soil %WSA and WHC but the significant species/ecotype differences need to be considered in discussions of the beneficial impacts of earthworms to soil properties.
Journal Article