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Due to the important process of global warming, the improvement of soil factors, which decrease wheat (Triticum aestivum L.) yield gap, in the arid and semi-arid areas of the world including Iran (Kerman province) is of significance. The objective was to determine how wheat yield gap and yield components, in 15 different fields (three different locations with areas ranging from 2993 to 5175 km2), are affected by soil physicochemical properties including texture, electrical conductivity (EC), pH, soil organic carbon (SOC), total nitrogen (TN), available phosphorus (P) and potassium (K), and chemical fertilization. Wheat yield components including tiller and grain number, fertile spike, spike length, 1000-grain weight (25–44 g), plant height, biological yield (plant dry weight) (4880–14800 kg/ha), and plant density were measured. Linear regression analyses indicated that SOC (0.23–1.51%), TN (0.02–0.15%) and available K (195–280 mg/kg) significantly affected wheat yield and yield components, which were also positively and significantly correlated. There was a positive and significant correlation between SOC, TN, and available P and K, which were negatively and significantly correlated with EC. The regression models relating soil physicochemical properties with spike length and plant height were significant (P ≤ 0.05). The R2 values ranged from 0.54 (number of grains per spike) to 0.90 (plant height) and for economic (grain) and biological yields were equal to 0.75 and 0.83, respectively. The yield gap was in the range of 1245–4256 kg/ha. The improvement of soil physicochemical properties may decrease wheat yield gap in the arid and semi-arid areas of the world. [ABSTRACT FROM AUTHOR]

Soil compaction has been recognized as a form of soil degradation that mostly deteriorates agricultural soil health worldwide from various climatic conditions and soil management. Heavy compaction can occur in agricultural soils due to intensive tillage, where its effects on soil properties have been the focus of many studies. The present study was undertaken to assess whether soil compaction occurs in agricultural soils adopting no-tillage systems and how the link between soil compaction and chemical-biological characteristics could be. A field investigation was carried out in two different locations that have different soil types, Entisol in Maitara Island and Ultisol in Halmahera Island, North Maluku Province. Sixteen undisturbed and disturbed soil samples were collected from each location grown with cassava and taken to the laboratory for analysis. Soil components observed included soil texture, bulk density, particle density, total porosity, soil permeability, soil organic matter (SOM), total nitrogen (N), phosphorous (P) availability, and phosphate-solubilizing bacteria (PSB). The findings revealed linear relationships between soil compaction and sand fraction, SOM, PSB, and available P, but none were found in soil total N. These results confirmed the importance of soil compaction management in food crop agricultural systems, particularly when soil carbon is low, to promote soil health. As the inconsistent correlation of soil compaction and chemical-biological properties was found in these two soil types, further investigation is necessary.

Soil compaction has been recognized as a form of soil degradation that mostly deteriorates agricultural soil health worldwide from various climatic conditions and soil management. Heavy compaction can occur in agricultural soils due to intensive tillage, where its effects on soil properties have been the focus of many studies. The present study was undertaken to assess whether soil compaction occurs in agricultural soils adopting no-tillage systems and how the link between soil compaction and chemical-biological characteristics could be. A field investigation was carried out in two different locations that have different soil types, Entisol in Maitara Island and Ultisol in Halmahera Island, North Maluku Province. Sixteen undisturbed and disturbed soil samples were collected from each location grown with cassava and taken to the laboratory for analysis. Soil components observed included soil texture, bulk density, particle density, total porosity, soil permeability, soil organic matter (SOM), total nitrogen (N), phosphorus (P) availability, and phosphatesolubilizing bacteria (PSB). The findings revealed linear relationships between soil compaction and sand fraction, SOM, PSB, and available P, but none were found in soil total N. These results confirmed the importance of soil compaction management in food crop agricultural systems, particularly when soil carbon is low, to promote soil health. As the inconsistent correlation of soil compaction and chemical-biological properties was found in these two soil types, further investigation is necessary. [ABSTRACT FROM AUTHOR]

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Climate change, land degradation and inadequate soil nutrients pose significant threats to food security and agricultural sustainability. This study aims to examine the effects of planting basins with farmyard manure on soil total carbon (C), nitrogen (N), isotopic C (d13C) and N (d15N) compositions within smallholder-managed farms in Makueni County, Kenya. The study involved two management practices: planting basins with manure (PM) and conventional farming practices (FP) in 12 experimental sites. Soil samples were taken at three depths (0-10, 10-20 and 20-40 cm), with three replicates for each treatment. Significant interactions were observed between land management practices and sites as well as land management practices and soil depth on soil total C and N. At each of the 12 sites, soil total C was higher under PM (ranging from 0.44% to 1.86%, p < .05) than FP management (ranging from 0.35% to 1.37%), across all soil depths. Soil total N concentrations ranged from 0.027% to 0.100% under FP and (0.060% to 0.190%, p < .05) under PM management. Across soil depths, higher (less negative) soil d13C values were observed under conventional farmer practice (range - 22.5? to -17.1?) compared with PM management range (-24.3? to -18.1?). Soil d15N was significantly enriched under PM management (range: 7.4? to 12.6?, p < .05) compared with the conventional farmer practices (range: 6.1? to 9.8?, p < .05). The findings show that planting basins with farmyard manure offers both climate mitigation and adaptation benefits by increasing soil C contents and improving soil fertility. The study provides insights into the real-world implications of these practices, emphasizing the potential of planting basins with manure in enhancing soil quality and climate resilience. [ABSTRACT FROM AUTHOR]

The southeastern Tibetan Plateau, which profoundly affects East Asia by helping to maintain the stability of climate systems, biological diversity and clean water, is one of the regions most vulnerable to water erosion, wind erosion, tillage erosion, freeze–thaw erosion and overgrazing under global climate changes and intensive human activities. Spatial variations in soil erosion in terraced farmland (TL), sloping farmland (SL) and grassland (GL) were determined by the 137Cs tracing method and compared with spatial variations in soil organic carbon (SOC) and total nitrogen (total N). The 137Cs concentration in the GL was higher in the 0–0.03 m soil layer than in the other soil layers due to weak migration and diffusion under low precipitation and temperature conditions, while the 137Cs concentration in the soil layer of the SL was generally uniform in the 0–0.18 m soil layer due to tillage-induced mixing. Low 137Cs inventories appeared at the summit and toe slope positions in the SL due to soil loss by tillage erosion and water erosion, respectively, while the highest 137Cs inventories appeared at the middle slope positions due to soil accumulation under relatively flat landform conditions. In the GL, the 137Cs data showed that higher soil erosion rates appeared at the summit due to freeze–thaw erosion and steep slope gradients and at the toe slope position due to wind erosion, gully erosion, freeze–thaw erosion and overgrazing. The 137Cs inventory generally increased from upper to lower slope positions within each terrace (except the lowest terrace). The 137Cs data along the terrace toposequence showed abrupt changes in soil erosion rates between the lower part of the upper terrace and the upper part of the immediate terrace over a short distance and net deposition on the lower and toe terraces. Hence, tillage erosion played an important role in the soil loss at the summit slope positions of each terrace, while water erosion dominantly transported soil from the upper terrace to the lower terrace and resulted in net soil deposition on the flat lower terrace. The SOC inventories showed similar spatial patterns to the 137Cs inventories in the SL, TL and GL, and significant correlations were found between the SOC and 137Cs inventories in these slope landscapes. The total N inventories showed similar spatial patterns to the inventories of 137Cs and SOC, and significant correlations were also found between the total N and 137Cs inventories in the SL, TL and GL. Therefore, 137Cs can successfully be used for tracing soil, SOC and total N dynamics within slope landscapes in the southeastern Tibetan Plateau.

Nitrogen (N), potassium (K), and phosphorus (P) are macronutrients that are paramount for plant physiology. The aim of this research is to evaluate the content and distribution of total N, and mobile K and P in soils historically polluted in the Copșa Mică area. We also calculated an average content of mobile P and K, highlighting the variation of the C/N ratio in the shallow depth layers of the soils within the sample surfaces. The negative impact on the soils of the main polluter of the Copșa Mică area is corroborated with a low total N content, minimal K concentration at the first depth layer, following a trend characterised by extremely low concentrations at the depth of 10-15 cm to extremely low to very low concentrations at the depth of 30-35 cm. The same trend is also noticed in the content of mobile P, the lower concentration classes being favoured in terms of average P content. [ABSTRACT FROM AUTHOR]

Background: Sorghum is the staple food crop in Assosa area and most important cereal crop next to teff and maize in Ethiopia. However, sorghum productivity is constrained by lack of improved agronomic practices, low soil fertility and associated low soil nutrient availability especially Nitrogen and Phosphorous deficiency and lack of integrated use of nutrient management practices. Objective: The objective of this study was to increase sorghum production and productivity by optimizing integrated use of blended NPS +N and FYM fertilizers in Assosa district, Western Ethiopia. Materials and Methods: The treatments consisted of four rates of FYM (0, 5, 10, and 15 t ha-1) and four rates of NPS (having 19N:38P:7S nutrient ratios) applied at the levels of 0, 50, 100 and 150% ha-1 along with N 46 kg ha-1. The experiment was laid out as a completely randomized block design in a factorial arrangement and replicated three times. The experiment was conducted for a period of two years, from 2020 to 2022. Data were collected on soil chemical properties and crop yield and yield attributes. Results: The results showed that the main effect of FYM and NPS significantly (P < 0.01) affected leaf area index, thousand seed weight and grain yield of sorghum. The integrated use of FYM and NPS significantly (P < 0.05) affected leaf area index, thousand seed weight, grain, and biomass and harvest index of sorghum. The soil pH (5.52 to 5.63), organic carbon (1.57 to 1.93%) and CEC (25 to 31.08 cmol(+) kg-1) were improved in response to the application of 15 t FYM ha-1, whereas some improvement of total nitrogen (0.15 to 0.18%) and available phosphorous (3.32 to 9.64 mg P kg-1) in response to the application of 150% NPS ha-1 + 46 kg N ha-1. The integrated use of 15 t FYM ha-1 and 150% NPS ha-1+ N 46 kg ha-1 resulted in the best improvement of soil organic carbon (0.85% to 2.95%, total nitrogen (0.15 % to 0.20%), available P (3.26 to 10.03 mg P kg-1) and CEC (18.2 to 36.92 cmol(+) kg-1). However, the highest soil pH (5.88) value was recorded in response to the integrated use of 10 t FYM ha-1and 150% NPS ha-1+ N 46 kg ha-1. The highest grain yield (3.98 t ha-1) was obtained from the integrated use of 10 t FYM ha-1 and 150% NPS ha-1 + N 46 kg ha-1. The highest biological yield (5.09 t ha-1) obtained from the integrated use of 15 t FYM ha-1and 150% NPS ha-1 + N 46 kg ha-1. However, the lowest grain yield (0.63 t ha-1) and biological yield (1.07 t ha-1) recorded from the non-treated plots respectively. This implies that the grain yield was increased over by 84.2% and biological yield by 78.9% respectively when compared to the control. Economic analysis also indicated that the application of 10 t farmyard manure ha-1and 150% NPS ha-1 + N 46 kg ha-1 was provided the highest gross and net benefit. Conclusion: It is concluded that the application of 10 t FYM ha-1and 150% NPS ha-1 + N 46 kg ha-1 resulted in the most economical yield and improved soil chemical properties, particularly soil organic carbon and available phosphorous. The highest mean net benefit (24, 640.14 ETB ha-1) was obtained from the application of 10 t FYM ha-1 and 150% NPS ha-1 + N 46 kg ha-1. This implies that combined applying of farmyard manure and mineral fertilizers at the above mentioned rates enhances the grain yield of sorghum accompanied enhanced contents of soil organic carbon and total nitrogen for sustainable production of the crop. [ABSTRACT FROM AUTHOR]

Analyzing the temporal and spatial evolution of soil nutrients is a prerequisite for implementing precision agriculture and sustainable soil management. The spatial and temporal variation characteristics of soil organic matter, total N, available P, and available K in arable soil in Suzhou City in 2010 and 2019 were analyzed by inverse distance weighted spatial interpolation analysis method. The results showed that the soil nutrients of arable soil in Suzhou increased slightly in 2019 compared with 2010. The soil organic matter of arable soil was relatively scarce in Dangshan County, Xiaoxian County, and Sixian County, and abundant in the middle towns of Yongqiao District, with an average value of 17.95 g·kg-1, an increase of 6.15%. The area with intermediate soil organic matter content accounted for 76.00% of the total cultivated land area; the soil total N content was the same, with an average value of 1.06 g·kg-1. The area with medium soil total N content accounted for 60.80% of the total cultivated land area. The available P in arable soil was more abundant in the southern townships of Dangshan, with an average value of 16.44 mg·kg-1, an increase of 10.73%. However, the available P in arable soil was lacking in the northern Yongqiao District, and deficient in the northern and southern towns of Sixian. The area with medium content of available P in arable soil accounts for 60.33% of the total arable soil area. The soil available K in arable soil was generally medium in Xiaoxian and Dangshan, rich in towns in the middle of Yongqiao District, towns in the west of Lingbi, and abundant in towns in the north of Sixian, with an average value of 149.37 mg·kg-1 an increase of 9.84%.The area with intermediate available K in soil accounts for 47.30% of the total arable soil area. The content of available P in sandy ginger black soil, paddy soil, and yellow-cinnamon soil increased significantly, with an increase of 27.76%, 23.08% and 16.68%, respectively. The content of available K in sand black soil and paddy soil increased slightly by 18.37% and 14.62%. The available K of limestone soil decreased slightly by 11.86%. The soil nutrients of arable soil in Suzhou City showed a general increase in organic matter, stable total N, a significant increase in available P, and a steady increase in available K. The northern part of Suzhou City should pay attention to increasing the application of organic fertilizer and nitrogen fertilizer, and the eastern part should pay attention to supplementing phosphate fertilizer and potassium fertilizer. [ABSTRACT FROM AUTHOR]

Soil fertility describes the soil's capacity to support the growth of agricultural plants for predictable yields. Consequently, the present study was conducted on twenty one soil series of Bangladesh, including Sonatala, Sherpur, Ghatail, Balina, Melandaha, Tarakanda, Gorargaon, Karail, Raipur, Ruhea, Silmandi, Dhamrai, Jamun, Ishurdi, Ranisankail, Atwari, Gangachora, Pirgachha, Sulla, Birampur, and Gopalpurand to know the fertility status and its possible sustainable agricultural packages. The textural classes of the major soils were silt loam. The soils had the particle densities ranged from 1.79 to 2.50 g cm-3. The soil series from Sherpur and Gangachora had the highest particle density, while those from Karail and Gorargaon had the lowest value. Most soils reacted in a neutral to acidic manner, whereas the Ishurdi and Gopalpur series showed an alkaline response. Except Karail and Gorargaon, the organic matter status was very low to medium. The total N content of the soils ranged from 0.04 to 0.19%. The available phosphorus, exchangeable potassium, and available sulphur of soils ranged from 2.82 to 22.18 ppm, 0.09 to 0.26 meq/100g soil, and 2.90 to 20.30 ppm, respectively. The results revealed that the soils in the research area were very low to moderately fertile. Therefore, balance fertilizer must be applied in time in the study area. The fertilizer should be location-specific, cropping pattern-based, and based on soil testing. Beside this, a collection of management techniques have to be acknowledged and promoted to the farmer level as a package for sustainable agriculture that enhances food security. [ABSTRACT FROM AUTHOR]

Hydrological models are effective tools for assessing the effects of soil and nutrient losses on land degradation. SWAT (Soil and Water Assessment Tool) model is widely used to simulate soil and nutrient losses caused by various management regimes. However, its performance of predicting nutrient loss has not been assessed adequately on the Loess Plateau. This study proposed a modified SWAT model by incorporating the modified Soil Conservation Service curve number method, the storm-based Chinese soil loss equation and the nutrient loss model. The observed daily data of runoff and sediment over 16 years and the monthly soluble phosphorus (P) and nitrate losses over 9 years and 4 years, respectively at the outlet of the upper Beiluo river (UBR) basin were used to assess the model performances. Global sensitivity and uncertainty analyses of parameters to runoff, sediment, soluble P and nitrate in the modified SWAT were conducted. The findings during calibration and validation showed that the modified SWAT was highly accurate in terms of model efficiency (calibration: 0.83, 0.83, 0.48, and 0.49; validation: 0.58, 0.57, 0.53, and 0.65) for runoff, sediment, soluble P loss and nitrate loss, respectively. High model efficiency indicated that the modified SWAT could accurately predict soil and nutrient losses at the river basin scale for the Loess Plateau. Moreover, the temporal variations from month to year and the spatial variations at the sub-basin scale for soil loss and the total N and P losses were analysed using the data simulated by the modified SWAT. The results indicated that the critical loss period occurred in July and August, and the Grain for Green project significantly affected the hydrological behaviour and reduced the soil and nutrient losses in the UBR basin.

The influence of altitude, pH, organic C and total nitrogen content on the Quantity and Distribution of soil microflora in the organic layers of Luvisols was investigated. The experimental plots include A horizon of 5 soil profiles. Aiming to determine the biogenity of analyzed plots, the total microbial number and the percentage share of different microbial groups has been examined. The samples were taken from forest soil according to microbiological requirements. The standard microbiological method for analyses was used. The obtained results showed different biogenity and percentage share of microbial groups according to the different environmental conditions - pH, org. C and total N. Strong correlation between total microbial number and org. C and total N has been found. Soil with the largest total microbial number (6.7 lg CFU/g dry soil) was the soil with the highest account of org. C (49.98 g.kg-1) - tested plot (TP) 2. pH as a parameter of soil environment has been correlated with the distribution of microbial groups. [ABSTRACT FROM AUTHOR]

Over 30% of the Chinese tea plantation is supplied with excess fertilizer, especially nitrogen (N) fertilizer. Whether or not foliar N application on tea plants at the dormancy stage could improve the quality of spring tea and be a complementary strategy to reduce soil fertilization level remains unclear. In this study, the effects of foliar N application on tea plants were investigated by testing the types of fertilizers and their application times, and by applying foliar N under a reduced soil fertilization level using field and 15N-labeling pot experiments. Results showed that the foliar N application of amino acid liquid fertilizer two times at the winter dormancy stage was enough to significantly increase the N concentration of the mature leaves and improved the quality of spring tea. The foliar application of 2% urea or liquid amino acid fertilizer two times at the winter dormancy stage and two times at the spring dormancy stage showed the best performance in tea plants among the other foliar N fertilization methods, as it reduced the soil fertilization levels in tea plantations without decreasing the total N concentration of the mature leaves or deteriorating the quality of spring tea. Therefore, foliar N application on tea plants at its dormancy stage increases the N concentration of the mature leaves, improves the quality and yield of spring tea, and could be a complementary strategy to reduce soil fertilization levels.

Over 30% of the Chinese tea plantation is supplied with excess fertilizer, especially nitrogen (N) fertilizer. Whether or not foliar N application on tea plants at the dormancy stage could improve the quality of spring tea and be a complementary strategy to reduce soil fertilization level remains unclear. In this study, the effects of foliar N application on tea plants were investigated by testing the types of fertilizers and their application times, and by applying foliar N under a reduced soil fertilization level using field and 15N-labeling pot experiments. Results showed that the foliar N application of amino acid liquid fertilizer two times at the winter dormancy stage was enough to significantly increase the N concentration of the mature leaves and improved the quality of spring tea. The foliar application of 2% urea or liquid amino acid fertilizer two times at the winter dormancy stage and two times at the spring dormancy stage showed the best performance in tea plants among the other foliar N fertilization methods, as it reduced the soil fertilization levels in tea plantations without decreasing the total N concentration of the mature leaves or deteriorating the quality of spring tea. Therefore, foliar N application on tea plants at its dormancy stage increases the N concentration of the mature leaves, improves the quality and yield of spring tea, and could be a complementary strategy to reduce soil fertilization levels. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is a crop macronutrient of major importance, which affects both plant growth and yield. In this paper we discuss the humus content (%) and various soluble N forms (NO 3 -, total N, nitrate-N, ammonium-N, and organic nitrogen) available in humus sand soil samples originating from the Pallag Experimental Station of Horticulture at the University of Debrecen, Hungary. We found 45.4% nitrate-N and 13.8% nitrite-N of total N content present in the soil. Considering the percentage distribution of soluble N forms present at the Pallag Experimental Station, we recommend using this soil in further pot experiments, given that this has optimal nutrient supply capacity. In addition, we examined possible statistical correlations between humus% and N forms.

Nitrogen (N) is a crop macronutrient of major importance, which affects both plant growth and yield. In this paper we discuss the humus content (%) and various soluble N forms (NO 3 -, total N, nitrate-N, ammonium-N, and organic nitrogen) available in humus sand soil samples originating from the Pallag Experimental Station of Horticulture at the University of Debrecen, Hungary. We found 45.4% nitrate-N and 13.8% nitrite-N of total N content present in the soil. Considering the percentage distribution of soluble N forms present at the Pallag Experimental Station, we recommend using this soil in further pot experiments, given that this has optimal nutrient supply capacity. In addition, we examined possible statistical correlations between humus% and N forms.

Converting alfalfa (Medicago sativa L.) into annual cropland (rotated cropland, RC) is commonly done to reuse degraded alfalfa pasture. However, it is a big challenge for RC to achieve high productivity and maintain high soil organic carbon (SOC) to the levels achieved by previous alfalfa pasture. We converted a long‐term alfalfa pasture into RC in 2010, and studied the effects of fertilization on soil moisture, crop productivity, and SOC in the RC and in continuous cropland (CC), both under plastic film mulching, from 2010 to 2018. Before the conversion, alfalfa pasture had a higher SOC (12.3%) and total N (7.7%) than CC. However, not only severe soil desiccation occurred, but the available P and inorganic‐N were only about 39.4 and 25.1% of levels for CC. After the conversion, soil moisture in RC (measured at 0–0.6 m depth) was up to CC levels only after 1 year, and was restored to 95.3 and 69.2% of CC levels at 0.6–2 and 2–5 m depths only after 9 years. Crop yield and biomass in RCF (RC with fertilization) were comparable to those for CCF (CC with fertilization) after two years from conversion due to the increased available P and inorganic‐N, and sufficient soil moisture restoration at 0–0.6 m depath. SOC in RC decreased by 8.1% over the 9 years, while RCF consistently kept SOC levels up to those of pre‐conversion alfalfa pasture. These findings help to eliminate concerns about the continuously low production and rapid decline of SOC in croplands converted from alfalfa and suggest ways to support sustainable high‐productivity and high SOC sequestration in dryland farming. [ABSTRACT FROM AUTHOR]

Pomace from tomato paste is produced in great amounts after tomato processing industries in Greece. The aim of this study is to evaluate tomato pomace as fertilizer in sweet maize cultivation. Two-year experiments were set up in West Greece under organic cultivations. The experiments followed a randomized complete block design, with four treatments, with which were different fertilizer applications (control, Tomato pomace, Tomato pomace & inorganic fertilizer (NPK), Tomato pomace & manure) in three replications. The root density, root surface, and symbiotic of arbuscular mycorrhizal fungi (AMF) were statistically affected by fertilization for both years, and the combination of Tomato pomace (Tp) and manure gave the highest values. Organic carbon (C) was significantly affected by year and fertilization, as well as the total nitrogen (N) was significantly affected by fertilization. Soil porosity under tomato pomace and mix of tomato pomace and inorganic fertilizer do not show statistically significant differences. The highest values for plant growth and leaf area index were under the combination of tomato pomace and manure. The yield was statistically affected by fertilization and year. Therefore, tomato mixtures with manure as well as compost had the most positive results in almost all parameters of the studies. [ABSTRACT FROM AUTHOR]

Rosa roxburghii Tratt., is an important commercial horticultural crop in China due to its nutritional and medicinal value. To date, the economic production of a single predominant cultivar of R. roxburghii (‘Guinong 5’) consumes 30 000 hm2 in China. Here, we characterize the amino acid composition of ‘Guinong 5’ and two novel genotypes (AL11, GP6) that prove valuable and deserve wide application. Here, 17 amino acids (acid hydrolysis of proteins) were detected in ‘Guinong 5’, AL11 and GP6 fruits, with Glutamine and Asparagine being abundant, and L-cystine being absent. The essential amino acids and total amino acids were the highest in AL11, while Asparagine was most abundant in GP6. For the free amino acid, 18 amino acids and 9 metabolites were detected in ‘Guinong 5’, AL11 and GP6 fruits. γ-aminobutyric acid, L-arginine and ornithine were the most abundant in ‘Guinong 5’, while phosphoserine and taurine were the highest in AL11. In comparison, GP6 had the highest levels of L-asparagine, an essential amino acid, and the highest total N containing compounds.

Aim of study: A field study was conducted to assess responses of soil organic C (SOC) and total N (TN) to film mulching and manure, which were important in identifying the changes of SOC and TN. Area of study: A semiarid area in northwestern China. Material and methods: The field (soil classified as CumuliUstic Isohumosol) has been planted with spring maize (Zea mays L.) for years. Three treatments were: 1) NPK fertilization and no film mulching (CK), 2) NPK fertilization and film mulching (PF) and 3) film mulching and NPK fertilization combined with cow manure (OMF). Main results: Compared with CK, OMF significantly increased SOC and TN, while no significant effect was observed under PF. The average increases of SOC storage in OMF were 39.2% in 0-10 cm layer and 34.3% in 10-20 cm layer. The average increases of TN storage were 37.6% in 0-10 cm layer and 31.3% in 10-20 cm layer, relative to CK. Compared with the initial SOC (8.86 g/kg) and TN (0.99 g/kg), CK and PF decreased 1.4% and 6.9% of SOC, and 9.1% and 17.2% of TN, whereas OMF increased SOC and TN. The SOC/TN was not affected by treatments but slight increase was observed since the beginning of experiment. Both PF and OMF significantly increased maize grain yields (on average 45.8% and 75.7%, respectively) compared with CK. Research highlights: Manure combined with film mulching significantly increased soil C and N, ameliorating harmful effects of plastic film mulching, improving soil fertility in the long term and increasing crop yields.

Copyright of Mediterranean Agricultural Sciences is the property of Akdeniz Universitesi Ziraat Fakultesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Optimization of phosphorus (P) fertilization is important for balancing soil fertility especially in vertisol to support economic crop production. The objective of the study was to determine the impact of P fertilization (1998 to 2014) on crop yield and nutrient uptake, and soil fertility under continuous annually tilled corn (Zea mays L.)-wheat (Triticum aestivum L.) system in semi-arid Mediterranean conditions. The study was conducted on Arik clay (isohyperthermic, fine clay Typic Haploxerert) using randomized complete block design with four replications for each treatment at the research farm of the Dept. of Soil Science and Plant Nutrition, Çukurova University, Adana, Turkey. P fertilizer at 0, 50, 100, 200 kg P2O5 ha−1 as triple superphosphate (TSP), respectively was applied a week before planting corn. Results showed that increasing P fertilization rates significantly decreased the number of mycorrhizal spores associated with corn roots. Similarly, a 10% decrease in corn root mycorrhizal colonization was observed with 200 kg P2O5 ha−1 fertilization. In the control treatment, corn yield was 4.3 Mg ha−1 as compared to 5.6, 5.7 and 6.1 Mg ha−1 in 50, 100 and 200 kg of P2O5/ha, respectively. The relationship between P fertilization and relative yield showed that more than 95% of the corn yield was produced when P applied at 100 kg P2O5 ha−1. While P fertilization significantly increased the leaf N, P, and K contents but decreased the leaf Zn, Fe and Mn contents, as compared with the control. However, P fertilization did not consistently affect the grain N and P contents. Both physiological efficiency- and agronomic efficiency of P fertilization have shown a significant non-linear increase than that of the control. Total organic C (TOC) and total N (TN) concentrations were more than 34 and 26% higher in 100 and 200 kg P2O5 ha−1rates as compared with the control. Likewise, available P (AP), manganese (Mn) and zinc (Zn) concentrations increased with an increase in P fertilization rates. The AP, Mn and Zn contents significantly stratified by P fertilization. Our results suggested that 100 kg P2O5 ha−1 is optimum to sustain Vertisol fertility for supporting economic corn production in the Mediterranean climates of Turkey. [ABSTRACT FROM AUTHOR]

Few studies have focused on the effects of long-term forest plantations on the soil profile of carbon (C) and nitrogen (N) stocks. In this study, we selected 78-year-old tree plantations that included three coniferous tree species (i.e., slash pine, hoop pine and kauri pine) and a Eucalyptus species in subtropical Australia. We measured soil extractable organic C (EOC) and N (EON) contents and total C and N stocks under different tree species on the forest floor and along a soil profile to 100 cm depth. The results showed that Eucalyptus had significantly higher soil EOC contents (3.3 Mg ha) than the other tree species (EOC of 1.9-2.3 Mg ha) and had significantly higher EON (156 kg ha) contents than slash pine (107 kg ha). Eucalyptus had significantly higher soil C (58.9 Mg ha) and N (2.03 Mg ha) stocks than the other tree species (22.3-27.6 Mg C ha and 0.71-1.23 Mg N ha) at 0-100 cm depth. There were no differences in soil C stocks at the 0-100 cm depth among the coniferous tree species. Forest floor C stocks had stronger effects on mineral soil total N stocks than fine root biomass, whereas fine root biomass exerted stronger effects on soil total C stocks at the 0-100 cm depth than forest floor C and N stocks. Our results addressed large differences in soil C and N stocks under different tree species, which can provide useful information for local forest management practices in this region. [ABSTRACT FROM AUTHOR]

Using the 137 Cs technique, we assessed spatial variation in soil erosion and its impact on lateral movements of soil organic carbon (SOC) and total nitrogen (total N) in a terraced series and a complex slope in the Longmenshan Fault zone, China. The complex slope derived from three terraced fields with damaged banks, resulting from the 8.0 Wenchuan Earthquakes in 2008. The terraced series and complex slope are the dominant sloping farmland patterns in this area, which represent for earthquake non-affected and affected sloping farmland, respectively. Soil loss occurred over the upper parts of slopes and deposition occurred towards the downslope boundary of each terrace. Also, soil loss occurred on upper terraces and soil accumulation on lower terraces. Net soil erosion rates for the terraced toposequence were estimated at − 3.70 ± 14.38 Mg ha − 1 yr − 1 , indicating the terraced toposequence played an important role in soil conservation. For the complex slope, higher soil erosion rates occurred at the summit and other slope positions with greater slope curvature, and soil accumulation occurred at the toe slope and other slope positions with lower slope curvature (15 m, 25 m, and 40 m). In addition to water erosion, collapses resulting from earthquake and tillage erosion were also important soil erosion processes for the complex slope. Moreover, Net soil erosion rate on the complex slope (4.89 ± 18.03 t ha − 1 yr − 1 ) was significantly higher than on the terraced series. SOC and total N inventories showed similar patterns to the 137 Cs inventory. Such results confirm that 137 Cs can help to trace SOC and total N dynamics on sloping farmland in this area. [ABSTRACT FROM AUTHOR]

Nitrogen is essential for plant growth and development and directly influences both grain production and oil content. Boron has been studied in sunflower cultivation due to high demand of this culture for this nutrient. This study aimed to evaluate the N and B differential supply effect on the grain and oil production of sunflower plants. The experiment was conducted in a greenhouse and used two sunflower hybrids: BRS 321 and Neon. N and B were applied via nutritive solution according to the following treatments: B + 50 N (2.49 kg ha-1 B and 10 kg ha-1 N at planting and 40 kg ha-1 B as additional fertilization); B + 10 N (2.49 kg ha-1 B and 10 kg ha-1 N at planting); 50 N (0 B and 10 kg ha-1 N at planting and 40 kg ha-1 N as additional fertilization) and 10 N (0 B and 10 kg ha-1 N at planting). Analyses of total N and B in all collected plant parts were performed, as well as measurements of grain production for each chapter and oil extraction at the end of the cycle. The association between B fertilization and a greater amount of N fertilization was essential to BRS 321 oil production. Regarding grain production at lower levels of N fertilization, Neon presented the best response to B application.

Com o objetivo de avaliar as alterações em algumas propriedades químicas do solo sob adição sucessiva de composto de lixo urbano, conduziu-se um experimento a campo, em um solo Argissolo Vermelho de textura média na Estação Experimental Agronômica da UFRGS. Os tratamentos constaram de cinco doses de composto (0, 20, 40, 80 e 160t ha-1), de um tratamento com adubo mineral e uma testemunha (Calagem e NPK), com aplicações sucessivas por um período de quatro anos. A adição de composto no solo aumentou o pH, CTC, C orgânico, N total, P e Na extraíveis, bem como da relação de adsorção de sódio (RAS), Ca e Mg trocáveis e o teor de K extraível após a terceira aplicação. O Al trocável teve os seus teores diminuídos após aplicações sucessivas de composto. Os resultados permitiram concluir que aplicação de até 80t ha-1 por ano de composto de lixo urbano pode ser considerada como adequada para melhorar e, ou, manter as propriedades químicas do solo.In order to assess the changes in some chemical properties of soil under the successive addition of urban waste compost, it was conducted a field experiment in an Ultisol soil at Agronomic Experimental Station of UFRGS. The treatments consisted of five successive applications of different doses of municipal solid waste compost (0, 20, 40, 80 and 160t ha-1) for a period of four years and a comparative treatment with mineral fertilizer and a control (without compost and fertilization). The addition of the compost increased soil pH, CEC, organic C, total N, extractable P and Na and the sodium adsorption ratio (SAR), calcium, and magnesium and extractable K after the third application. The exchangeable Al had their levels reduced by successive applications of compost. The results showed that application of up to 80t ha-1 yr-1 of urban waste compost can be the dose recommended to improve and maintain the chemical properties of soil.

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Chagan Lake serves as an important ecological barrier in western Jilin. Accurate water quality series predictions for Chagan Lake are essential to the maintenance of water environment security. In the present study, a hybrid AutoRegressive Integrated Moving Average (ARIMA) and Radial Basis Function Neural Network (RBFNN) model is used to predict and examine the water quality [Total Nitrogen (TN), and Total Phosphorus (TP)] of Chagan Lake. The results reveal the following: (1) TN concentrations in Chagan Lake increased slightly from 2006 to 2011, though yearly variations in TP were not significant. The TN and TP levels were mainly classified as Grades IV and V, (2) The hybrid ARIMA and RBFNN model's RMSE values for the observed and predicted data were 0.139 and 0.036 mg L-1 for TN and TP, respectively, which indicated that the hybrid model describes TN and TP variations more comprehensively and accurately than single ARIMA and RBFNN model. The results serve as a theoretical basis for ecological and environmental monitoring of Chagan Lake and may help guide irrigation district and water project construction planning for western Jilin Province. [ABSTRACT FROM AUTHOR]

Microorganisms degrade a great variety of chemical substances including pesticide residues in soil. By virtue of low persistence and broad-spectrum efficacy, pyrethroid insecticides are sometimes used in tea garden to combat insect pests but the residual effects of these chemicals on microbial activities in soil have rarely been studied. The present experiment has been conducted under laboratory conditions to investigate the effect of four synthetic pyrethroid insecticides, viz. cypermethrin, deltamethrin, fenvalerate and permethrin at their field application rates (225, 200, 225, 210 g a.i. ha −1 , respectively), on growth and activities of microorganisms in relation to non-symbiotic N 2 -fixation and N mineralization in a tea garden soil of the Himalayan terai (at the lower base) region of West Bengal, India. Application of insecticides, in general, decreased growth and activities of ammonifying and nitrifying bacteria but increased proliferations of non-symbiotic N 2 -fixing bacteria, resulting in greater fixation of atmospheric N 2 , more so with permethrin (7.8%) followed by cypermethrin (5.2%). Most of the insecticides had a deleterious effect on the accumulation of oxidizable organic C and total N, more pronounced with fenvalerate and permethrin. The availability of exchangeable NH 4 + was also significantly reduced, more prominently with fenvalerate (15.6%) followed by deltamethrin (11.2%), while permethrin followed by cypermethrin accentuated greater accumulation of soluble NO 3 − in soil. Therefore, the effects of synthetic pyrethroid insecticides on microbial activities in relation to non-symbiotic N 2 -fixation and its mineralization in tea soil of West Bengal can not be generalized, rather in most cases the effects were inclined more towards detrimental than a few stimulative one. [ABSTRACT FROM AUTHOR]

The introduction of trees in cropland may be a way to improve the mineral nitrogen (N) use efficiency since tree roots can intercept N leached below the crop rooting zone and recycle it as organic N. The aim of this study was to determine soil mineral N (SMN) and total N (STN) contents after 14 years of hybrid walnut tree growth in an agroforestry system. Soil cores were collected and analyses in mid-autumn 2009, in intercropped agroforestry (AF), pure tree (FC) and sole crop control (CC) plots. The SMN was significantly reduced in AF compared to CC (64, 58 and 51 % of reduction at 0.2, 1 and 2 m depth respectively). In the top 1 m of soil, the stock of SMN was 77.7 kg N ha in CC versus 32.8 kg N ha in AF. Trees in AF developed deeper fine roots than in FC, likely involved in the reduction of SMN when compared to CC. Despite this quantitative reduction, trees also progressively modified the form of mineral N in soil by decreasing the percentage of nitrate (NO) in SMN, particularly in FC compared to CC, while AF was intermediate. The STN was not significantly different between AF and CC; but was higher in FC in the top soil, probably due to weeds and superficial tree root biomasses. Our results suggest that the introduction of hybrid walnut trees into cropland may be an efficient practice to reduce the potentially leachable N by winter rainfall. [ABSTRACT FROM AUTHOR]

O presente trabalho teve por objetivo avaliar o efeito do tipo de vegetação e da época de amostragem na atividade da urease em dois diferentes solos tropicais. O experimento foi instalado em Latossolo Vermelho Aluminoférrico típico e Latossolo Vermelho distrófico típico sob cinco diferentes culturas: pinus, eucalipto, citrus, soja e milho. As amostragens de solo foram efetuadas mensalmente, de abril de 1990 a março de 1991, determinando-se a atividade da urease, o N-total e o C-orgânico. A atividade da urease variou de acordo com a época de amostragem, apresentando valores mais elevados nos meses mais quentes e úmidos. A cobertura vegetal influenciou a conversão de N-uréia a N-NH4, observando-se maior atividade da urease nas amostras de solo sob pinus e eucalipto, embora, no início do ciclo das culturas da soja e do milho, a atividade da urease também tenha sido elevada.The present study aimed to evaluate the effect of the vegetation type and the sampling time on urease activity in two different tropical soils (Rhodic Oxisols). The experiment was installed in a typic alumino-ferric Red Latossol and a typic distrophic Red Latosol under five different vegetations: pinus, eucalypt, citrus, soybean and corn. The soil samples were collected from April 1990 to March 1991 and the urease activity, total nitrogen and organic carbon were determined. The urease activity changed according to the sampling time, presenting higher values in the warmer and humid months. The vegetation type affected the conversion of N-urea to N-NH4+, with higher urease activity being observed in the soil under pinus and eucalypt, although the activity was high at the beginning of the soybean and corn cropping cycle.

This research reports and analyzes results of a field experiment started in 1984, when hard coal fly ash (HCFA) was added to soil at doses of 0 to 800 Mg⋅ha-1. During the first years of the experiment, traditional crops were grown in the plots, which in 1992 were converted into permanent grassland. Twenty-nine years after the application of fly ash, soil samples from the 0-20 cm soil layer were collected to determine chemical properties of soil. The results showed an elevated soil reaction, and high contents of available forms of P, K, and Mg, plus mineral forms of nitrogen and high soil organic matter. Under increased ash doses, analysed soils increased the C:N ratio and shares of N-NO3 and N-NH4 in total nitrogen content. These results justify that fly ash from combustion of hard coal in a power plant can produce long-term impact on soil, contributing to a certain improvement of its chemical, physical, and biological properties, which stimulate the sequestration of carbon in soil. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southern Agriculture is the property of Journal of Southern Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Several national-scale studies have shown that reactive N is accumulating in developed countries even when only the terrestrial biosphere is considered. However, none of these studies was able to consider the total N budget and so any discrepancy in budgets could be dismissed as being accounted for by N exchange. This study considered a large (9,948 km), mixed agricultural catchment where records of N flux, land use, climate and population go back at least to 1883. The N inputs were: biological nitrogen fixation, food and feed transfers, atmospheric deposition and inorganic fertilizers. The N outputs were atmospheric emissions (NH, NO, NO, N), direct waste losses and fluvial losses at the soil source. The results showed that, prior to the large-scale use of inorganic fertilizers, the total N budget of the catchment was at steady state with only a small net loss of total N. After the widespread introduction of inorganic fertilizers, the balance of the catchment shifts in favour of the net accumulation. Even accounting for losses to groundwater, the catchment was found to have accumulated 315 ktonnes N (315 tonnes/km) at a rate of 5.5 tonnes N/km/yr (55 kg N/ha/yr) over 35 years since 1973. We propose that the accumulation of N could be occurring in subsoils of the catchment. [ABSTRACT FROM AUTHOR]

Highlights: [•] SOC and TN concentrations and stocks were evaluated. [•] The stratification ratios of SOC and TN in different land uses were studied. [•] Land uses at low cropping intensity have higher stratification ratios. [•] Microbial biomass and microbial quotient were in agreement with stratification ratios. [•] Optimum values of C:N were found in land uses at low cropping intensity. [Copyright &y& Elsevier]

In 0.8 m² microplots, a very poor sandy soil that contained only traces of organic matter was enriched with bentonite (BNT) at rates of 0, 3, 6, and 12 kg/m². For 30 years the microplots were planted with different crops and regularly enriched with mineral and organic fertilizers. For the next eight years the microplots were left barren. The soils with BNT added contained significantly higher amounts of organic carbon (OC) and total nitrogen than the control soil (CS). Furthermore, in comparison to CS, organic matter in the soil with 12 kg/m² of BNT contained significantly more humins. Such durable stabilization of OC by BNT can be important for processes of carbon sequestration in soil. [ABSTRACT FROM AUTHOR]

The objective of the present study was to test the robustness of near infrared spectroscopy (NIRS) for the prediction of total N content in underground storage organs across a diverse range of root and tuber crop varieties. Overall, 1096 accessions (acc.) from five different species (cassava = 112 acc., cocoyam =117 acc., sweet potato = 225 acc., taro = 306 acc. and yams = 266 acc.) were chemically analysed for total N and minerals, as well as starch, sugars and cellulose. For validation of the models, 178 samples composed of the same five different species were collected in farmers’ fields, at random. All spectra were taken over the wavelength range of 350–2500 nm. Partial least-squares (PLS1) regression technique was used to develop predictive models. Their comparison with the chemical values allowed the establishment of equations of calibration. In terms of predictive performance, the equation for total N should be considered as very good with ar2predof 0.93 (SEP = 0.87). Minerals presented lowr2predof 0.62 (SEP = 1.05). Starch and sugars presentedr2predof 0.77 and 0.86, respectively (SEP = 3.2 and 1.82). Cellulose could not be satisfactorily predicted with a lowr2cv(0.57) for the calibration. Ther2predvalues of total N, starch and sugars are high enough to allow good estimates of their contents, confirming the interest of NIRS for predicting rapidly these major compounds. Potential applications are discussed. [ABSTRACT FROM AUTHOR]

The long-term positive effects of cropping systems involving rotation with cover crops on soil properties and the environment are well recognized. The present work concerns a 3-year field experiment focusing on two cropping systems including two energy crops [maize (Zea maysL.) and sunflower (Helianthus annuusL.)] cultivated May–September on an infertile sandy soil, andPisum sativumcultivated as cover crop after the harvest of the energy crop. Soil samples from two soil layers, 0–20 cm and 20–40 cm deep, were collected at the beginning and end of the experiments; they were analyzed for soil physical and chemical properties such as soil moisture properties, total nitrogen (N), phosphorus (P), potassium (K), pH, organic matter, and organic carbon (C). The results demonstrated the effect of pisum intercropping on the performance of the subsequent energy crop. These results are particularly important for the cultivation of less fertile soils such as sandy soils, which can be put in use for the production of energy crops such as maize and sunflower, which are characterized by high nutrient—particularly N—demand. [ABSTRACT FROM AUTHOR]

Abstract: Knowledge about the changes in carbon (C) concentration and mechanical and hydrological properties under different tillage and mulch treatments is necessary to assess the feasibility of adoption of conservation practices for sustaining productivity and protecting the environment. It is widely recognized that no-till (NT) farming conserves soil and water, saves energy, improves the environment and enhances soil quality. However, the magnitude and direction of tillage and mulch-induced changes are soil and site specific. Therefore, a field study was conducted on a long-term on-going experiment to evaluate the effects of three tillage {NT, ridge till (RT) and plow till (PT)} and three mulch rates (0, 8 and 16Mgha−1 yr−1) on soil physical properties and total C concentrations in macro (250–2000μm) and micro (<250μm) aggregates. The experiment was initiated in 1989 on a Crosby Silt Loam (Stagnic Luvisol) in Central Ohio. The data show positive effects of mulch rate on soil physical attributes and total C concentration under NT. Significant (P <0.05) variations in bulk density (ρ b) and penetration resistance (PR) along with their interactions were observed among tillage and mulch treatments. The water infiltration capacity (i c) ranged from 1.2cmh−1 (PT) to 4.6cmh−1 (NT). With increase in mulch rate from 0 to 16Mgha−1, saturated hydraulic conductivity (K s) for 0–10cm depth increased from 1.78 to 3.37, 1.57 to 2.95 and 1.37 to 2.28 (×10−2 cmh−1) under NT, RT and PT, respectively. Analyses of variance indicate significant interaction between tillage, mulch and soil depth for the K s. Similarly, the mean weight diameter (MWD, mm) increased from 0.36 to 1.21, 0.29 to 0.84, 0.25 to 0.62 under NT, RT and PT, respectively, with increase in mulch rate from 0 to 16Mgha−1. Total C (%) increased from 1.26 to 1.50, 1.20 to 1.47 and 0.95 to 1.10 under NT, RT and PT, respectively, with increase in mulch rate from 0 to 16Mgha−1. Macro-aggregates (250–2000μm) contained 30% more total C and N concentrations than microaggregates (<250μm). Under NT, the soil showed a higher structural stability than PT with significantly lower compaction values. Further, with NT the soil showed a higher capacity to retain C than PT. Thus, long term use of NT along with mulch application enhances soil quality with respect to soil mechanical, hydrological properties along with carbon concentration in the soil. [Copyright &y& Elsevier]

In order to assess the changes in some chemical properties of soil under the successive addition of urban waste compost, it was conducted a field experiment in an Ultisol soil at Agronomic Experimental Station of UFRGS. The treatments consisted of five successive applications of different doses of municipal solid waste compost (0, 20, 40, 80 and 160t ha-1) for a period of four years and a comparative treatment with mineral fertilizer and a control (without compost and fertilization). The addition of the compost increased soil pH, CEC, organic C, total N, extractable P and Na and the sodium adsorption ratio (SAR), calcium, and magnesium and extractable K after the third application. The exchangeable Al had their levels reduced by successive applications of compost. The results showed that application of up to 80t ha-1 yr-1 of urban waste compost can be the dose recommended to improve and maintain the chemical properties of soil. [ABSTRACT FROM AUTHOR]