Soil-structure changes in a long-term citrus experiment.

1953 ◽  
Vol 4 (2) ◽  
pp. 193 ◽  
Author(s):  
EL Greacen ◽  
O Perkman
Keyword(s):  
Organic Matter ◽  
Surface Layer ◽  
Aggregate Stability ◽  
Infiltration Rate ◽  
High Porosity ◽  
Capillary Porosity ◽  
Infiltration Rates ◽  
Structure Changes ◽  
Nitrogen Treatments ◽  
Bare Surface

Data are given on the changes induced in the physical properties of the soil in a factorial experiment in which cultural, irrigation, and nitrogen treatments are being tested on citrus. Apart from an increase in the non-capillary porosity of the surface layer to the depth of cultivation, there is no difference to be noted in porosity between the cultivated plots with the addition of organic matter and the uncultivated bare-surface plots where no organic matter is added. Under permanent sod the total non-capillary porosity is reduced but larger pores are present, 44 per cent. being in the form of insect burrows 2 mm. and more in diameter. The initial infiltration rates of the cultivated plots reflect the high porosity of the surface layer, but there is no difference in the final infiltration rates for these and the bare-surface plots. The infiltration rate of the sod plots is four times as high as in the other treatments, and is attributable to the effective hydraulic area of the faunal burrows. Cultivation has reduced aggregate stability as compared with uncultivated bare-surface and sod treatments, and the sod plots are considerably better in this respect than the bare-surface plots. This is not reflected in the soil organic carbon contents. Aggregate stability increases with increasing ammonium sulphate applications regardless of the cultural treatments. This is associated with increasing soil acidity, which, incidentally, may influence structure through its effect on microflora and exchangeable cations.

Influence of tillage and cropping system on soil organic matter, structure and infiltration in a rolling landscape

1999 ◽  
Vol 79 (3) ◽  
pp. 457-463 ◽  
Author(s):  
J. A. Elliott ◽  
A. A. Efetha
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Bulk Density ◽  
Aggregate Stability ◽  
Cropping System ◽  
Infiltration Rate ◽  
Conventional Tillage ◽  
Zero Tillage ◽  
Organic C ◽  
Infiltration Rates

The influence of tillage and cropping system on soil organic matter, structure and infiltration was studied in a rolling, glaciolacustrine landscape in Saskatchewan with slopes ranging from 6 to 30%. A field that had been continuously cropped using zero tillage (ZTCC) for 11 yr was compared with conventional tillage in a crop–summerfallow rotation (CTCF) on an adjacent field. Soils in each field were sampled according to their position in the landscape. Soil organic C, aggregrate size and aggregate stability were significantly greater on the ZTCC plot than the CTCF. Infiltration rates averaged 74 and 52 mm h−1 on the ZTCC and CTCF plots, respectively. Differences between treatments were most pronounced at the shoulder positions. Increased soil strength was measured on the CTCF plot at depths corresponding to the action of tillage implements (0.05 m and 0.15 m). On the CTCF plot, infiltration rates correlated with initial moisture, aggregate stability and bulk density but on the ZTCC plot consistent correlations were only found between infiltration and bulk density. When measured infiltration rates were compared with expected storm intensities, the differences in infiltration rates between treatments and their distribution in the landscape resulted in substantially more runoff from the CTCF plot than the ZTCC. Key words: Zero tillage, cropping frequency, infiltration rate, aggregation, organic carbon, landscape

scholarly journals Erosion Effect on Soil Physical Properties in Selected Farmlands in Gidan Kwano, Niger State

2018 ◽  
Vol 2 ◽  
pp. 10-22
Author(s):  
Abdulkadir Abdullahi
Keyword(s):  
Organic Matter ◽  
Physical Properties ◽  
Bulk Density ◽  
Organic Matter Content ◽  
Aggregate Stability ◽  
Clay Content ◽  
Infiltration Rate ◽  
Matter Content ◽  
Simple Method ◽  
Cumulative Infiltration

The study was conducted to investigate if erosion is a major problem and to identify the effect of erosion on some physical properties on selected farmlands on four farms in Gidan kwano. It was done by observation, interview, and questionnaire and soil sample analysis. The infiltration rate, bulk density, porosity, organic matter content, particle size and aggregate stability were determined for all the sample location. The erosion fields results were compared with the results of the non-eroded fields. The results showed that farming was done with simple method and mechanized equipment when available and erosion was considered a major problem in all the farms. The results revealed that bulk density values ranged between 1.475gcm-3and 1.606gcm-3, cumulative infiltration rate fluctuated between 29.75cm/hr and 37.48cm/hr, porosity ranged between 36.49% and 44.34%, organic matter content fluctuated between 0.29% and 0.73% and aggregate stability ranged between 58.00% and 67.60% for the erosion field. The results also revealed that bulk density fluctuated between 1.458gcm-3and 1.544gcm-3, cumulative infiltration rate ranged between 32.19 cm/hr and 40.48cm/hr, porosity fluctuated between 41.73% and 44.98%, organic matter content ranged between 0.30% and 1.09% and aggregate stability ranged between 63.97% and 68.93% for the non-eroded field. From the results, it provides evidence that the effects of erosion on the physical properties were increased bulk density, decreased infiltration rate, organic matter content, porosity, aggregate stability and percentage sand, silt and clay content. Statistical analysis proved that the results were significant (p<0.05) except for the bulk density and porosity which could be attributed to the swelling and compaction characteristics of the soils.

The role of active fractions of soil organic matter in physical and chemical fertility of Ferrosols

Soil Research ◽  
1998 ◽  
Vol 36 (5) ◽  
pp. 809 ◽  
Author(s):  
M. J. Bell ◽  
P. W. Moody ◽  
R. D. Connolly ◽  
B. J. Bridge
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Management Practices ◽  
Chemical Properties ◽  
Aggregate Stability ◽  
Infiltration Rate ◽  
Exchange Capacity ◽  
Organic C ◽  
Wide Range ◽  
Physical And Chemical

The relationships between fractions of soil organic carbon (C) oxidised by varying strengths of potassium permanganate (KMnO4) and important soil physical and chemical properties were investigated for Queensland Ferrosols. These soils spanned a wide range of clay contents (31-83%), pH values (4·4-7·9; 1 : 5 water), and total C contents (12· 1-111 g/kg). Carbon fractions were derived by oxidation with 33 mM (C1), 167 mM (C2), and 333 mM (C3) KMnO4, while organic C and total C were determined by Heanes wet oxidation and combustion, respectively. Aggregate stability was determined by wet sieving soil from the surface crust after 30 min of high intensity (100 mm/h), simulated rainfall on disturbed samples in the laboratory. The proportion of aggregates <0·125 mm (P125) was used as the stability indicator because of the high correlation between this size class and the final rainfall infiltration rate (r2 = 0qa86, n = 42). The soil organic C fraction most closely correlated with P125 was C1 (r2 = 0·79, n = 42). This fraction was also highly correlated with final, steady-state infiltration rates in field situations where there were no subsurface constraints to infiltration (r2 = 0·74, n = 30). Multiple linear regression techniques were used to identify the soil properties determining effective cation exchange capacity (ECEC, n = 89). Most variation in ECEC (R2 = 0 ·72) was accounted for by a combination of C1 (P < 0·0001) and pH (P < 0·0001). These results confirm the very important role played by the most labile (easily oxidised) fraction of soil organic matter (C1) in key components of the chemical and physical fertility of Ferrosols. Management practices which maintain adequate C1 concentrations are essential for sustainable cropping on these soils.

Agronomic Requirements for Soil Utilization in Liquid Waste Disposal Systems – The Case of Sitel

1987 ◽  
Vol 19 (8) ◽  
pp. 177-194
Author(s):  
Zeno Simon ◽  
Marino Tedesco
Keyword(s):  
Organic Matter ◽  
Liquid Waste ◽  
Infiltration Rate ◽  
Effluent Treatment ◽  
Grass Species ◽  
Infiltration Rates ◽  
Agronomic Management ◽  
Profile Depth ◽  
Ease Of Access ◽  
Final Effluent

At SITEL – the integrated effluent treatment system of Pólo Petroquímico do Sul (South Petrochemical Complex), Triunfo, State of Rio Grande do Sul, Brazil – both the final effluent and the thickened excess activated sludge are disposed of on land. Thorough agronomic investigations made possible the identification of appropriate soils for receiving the wastes and the establishment of some design criteria. Profile depth, texture, infiltration rate, internal drainage, slope and availability of land covered with intact vegetation were the main factors considered in the election of areas for effluent disposal. For sludge application the following factors were taken into account: drainage, slope, chemical characteristics (mainly pH and Organic Matter), distance to the sludge loading point, suitability to agronomic management, ease of access, topography and presence of an adequate grass species (pangola grass). The results of the preliminary agronomic investigations are presented and discussed. Design assumptions are confronted with actual operational data. Comparisons are made with other reported situations. A discussion on the limitations, shortcomings and incompleteness of the available criteria and guidelines is included, with particular focus on CEC, Infiltration Rates, Maximum Permissible Loadings, Nitrogen and Organic Matter.

Use of ultrasonic surface hardening in modifi cation of surface layer

2020 ◽  
pp. 200-204
Author(s):  
Yu.S. Semenova ◽  
A.G. Samul’ ◽  
S.V. Mazhuga
Keyword(s):  
Surface Layer ◽  
Chemical Treatment ◽  
Surface Hardening ◽  
Manufacturing Cost ◽  
Ultrasonic Vibrations ◽  
Surface Microrelief ◽  
Scientific Schools ◽  
Structure Changes ◽  
Wide Range ◽  
Finishing Machining

Overview of the research results got by various scientific schools in the field of application of ultrasonic surface hardening is provided. Wide range of opportunities of ultrasonic surface hardening is shown for the application in the preliminary machining of surfaces before thermal and chemical treatment, coating, and also as finishing machining. The effect of the energy of ultrasonic vibrations on structure changes in the material of the surface layer and on surface microrelief on parts performance is considered. The prospects of using of the ultrasonic surface hardening method in combination with other methods of the material modification are presented. In addition the possibilities of reducing the manufacturing cost of product by introducing ultrasonic surface hardening into the technological process are shown.

scholarly journals Impact of soil use on aggregate stability and its relationship with soil organic carbon at two different altitudes in the Colombian Andes

2019 ◽  
Vol 37 (3) ◽  
pp. 263-273
Author(s):  
Efraín Francisco Visconti-Moreno ◽  
Ibonne Geaneth Valenzuela-Balcázar
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Aggregate Stability ◽  
Tropical Climate ◽  
Mineral Particle ◽  
Organic Carbon Content ◽  
Rice Soils ◽  
Organic Matter Pool ◽  
Different Altitudes

The stability of soil aggregates depends on the organic matter, and the soil use and management can affect the soil organicmatter (SOM) content. Therefore, it is necessary to know therelationship between aggregate stability and the content of SOMin different types of soil use at two different altitudes of theColombian Andes. This study examined the conditions of soilaggregate stability expressed as a distribution of the size classes of stable aggregates (SA) and of the mean weighted diameter of the stable aggregates (MWD). To correlate these characteristics with the soil organic carbon (OC), we measured the particulate organic matter pool (POC), the OC associated with the mineral organic matter pool (HOC), the total organic carbon content (TOC), and the humification rate (HR). Soils were sampled at two altitudes: 1) Humic Dystrudepts in a cold tropical climate (CC) with three plots: tropical mountain rainforest, pastures, and crops; 2) Fluvaquentic Dystrudepts in a warm tropical climate (WC) with three plots: tropical rainforest, an association of oil palm and pastures, and irrigated rice. Soils were sampled at three depths: 0-5, 5-10 and 10-20 cm. The physical properties, mineral particle size distribution, and bulk density were measured. The content of SA with size>2.36 mm was higher in the CC soil (51.48%) than in the WC soil (9.23%). The SA with size 1.18-2.36 mm was also higher in the CC soil (7.78%) than in the WC soil (0.62%). The SA with size 0.60-1.18 mm resulted indifferent. The SA with size between 0.30 and 0.60 mm were higher in the WC soil (13.95%) than in the CC soil (4.67%). The SA<0.30 mm was higher in the WC soil (72.56%) than in the CC soil (32.15%). It was observed that MWD and the SA>2.36 mm increased linearly with a higher POC, but decreased linearly with a higher HR. For the SA<0.30 mm, a linear decrease was observed at a higher POC, while it increased at a higher HR.

scholarly journals Comparison of wheat and safflower cultivation areas in terms of total carbon and some soil properties under semi-arid climate conditions

2015 ◽  
Vol 7 (1) ◽  
pp. 1007-1024
Author(s):  
B. Turgut
Keyword(s):  
Organic Matter ◽  
Physical Properties ◽  
Organic Matter Content ◽  
Aggregate Stability ◽  
Soil Physical Properties ◽  
Matter Content ◽  
Total Carbon ◽  
Arid Climate ◽  
Soil Layers ◽  
Semi Arid

Abstract. The aim of this study was to compare the soils of the wheat cultivation area (WCA) and the safflower cultivation area (SCA) within semi-arid climate zones in terms of their total carbon, nitrogen, sulphur contents, particle size distribution, aggregate stability, organic matter content, and pH values. This study presents the results from the analyses of 140 soil samples taken at two soil layers (0–10 and 10–20 cm) in the cultivation areas. At the end of the study, it has been established that there were significant differences between the cultivation areas in terms of soil physical properties such as total carbon (TC), total nitrogen (TN), total sulphur (TS) contents and pH, while only the TN content resulted in significantly different between the two soil layers. Moreover significant differences were identified in the cultivation areas in terms of soil physical properties including clay and sand contents, aggregate stability and organic matter content, whereas the only significant difference found among the soil layers was that of their silt content. Since safflower contains higher amounts of biomass than wheat, we found higher amounts of organic matter content and, therefore, higher amounts of TN and TS content in the soils of the SCA. In addition, due to the fact that wheat contains more cellulose – which takes longer to decompose – the TC content of the soil in the WCA were found to be higher than that of the SCA. The results also revealed that the WCA had a higher carbon storage capacity.

Soil Management for Conservation and Sustainable Rice Production in an Irrigated Area of Eastern Nigeria

1996 ◽  
Vol 25 (3) ◽  
pp. 151-156 ◽  
Author(s):  
Charles L.A. Asadu
Keyword(s):  
Organic Matter ◽  
Bulk Density ◽  
Relative Proportion ◽  
Soil Management ◽  
Infiltration Rate ◽  
Water Infiltration ◽  
Negative Effects ◽  
Irrigation Project ◽  
Irrigated Area ◽  
Cropping Season

An comparison of soilmanagement techniques In the different irrigation zones of Lower Anambra Irrigation Project (LAIP) In eastern Nigeria showed that heavy use of machinery led to Increases In bulk density and decreases In field water Infiltration rate. The relative proportion of clay In the irrigated fields Increased as a result of Irrigation, suggesting that mobilized clay from uncemented main and distribution canals Is carried and deposited In the rice fields. Both Irrigation and the use of machinery have had substantial negative effects on soli nutrient levels, and there is a danger of this process continuing. Soli management for sustainable production in the area should centre on applying organic matter in combination with inorganic fertilizers, monitoring the soli properties on yearly basis before the cropping season for fertilizer and lime recommendations, and varying the depth of tillage to Increase or maintain the effective soli depth.

The effects of cultivation on the composition of organic-matter and structural stability of soils

Soil Research ◽  
1995 ◽  
Vol 33 (6) ◽  
pp. 975 ◽  
Author(s):  
A Golchin ◽  
P Clarke ◽  
JM Oades ◽  
JO Skjemstad
Keyword(s):  
Organic Matter ◽  
Chemical Composition ◽  
Organic Carbon ◽  
Organic Materials ◽  
Aggregate Stability ◽  
Soil Samples ◽  
Modulus Of Rupture ◽  
Dispersible Clay ◽  
Different Soils

Soil samples were obtained from the surface horizons of five untilled sites and adjacent sites under short- and long-term cultivation. The soil samples were fractionated based on density and organic materials were concentrated in various fractions which enabled comparative chemical composition of the organic materials in cultivated and uncultivated sites by solid-state C-13 CP/MAS NMR spectroscopy. Changes in the nature of organic carbon with cultivation were different in different soils and resulted from variations in the chemistry of carbon inputs to the soils and a greater extent of decomposition of organic materials in cultivated soils. Differences in the chemical composition of organic carbon between cultivated and uncultivated soils resided mostly in organic materials occluded within aggregates, whereas the chemistry of organic matter associated with clay particles showed only small changes. The results indicate a faster decomposition of O-alkyl C in the cultivated soils. Wet aggregate stability, mechanically dispersible clay and modulus of rupture tests were used to assess the effects of cultivation on structural stability of soils. In four of five soils, the virgin sites and sites which had been under long-term pasture had a greater aggregate stability than the cultivated sites. Neither total organic matter nor total O-alkyl C content was closely correlated with aggregate stability, suggesting that only a part of soil carbon or carbohydrate is involved in aggregate stability. The fractions of carbon and O-alkyl C present in the form of particulate organic matter occluded within aggregates were better correlated with aggregate stability (r = 0.86** and 0.88**, respectively). Cultivation was not the dominant factor influencing water-dispersible clay across the range of soil types used in this study. The amount of dispersible clay was a function of total clay content and the percentage of clay dispersed was controlled by factors such as clay mineralogy, CaCO3 and organic matter content of soils. The tendency of different soils for hard-setting and crusting, as a result of structural collapse, was reflected in the modulus of rupture (MOR). The cultivated sites had significantly higher MOR than their non-tilled counterparts. The soils studied had different MOR due to differences in their physical and chemical properties.

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