Soil Technology最新文献

{"title":"Variability of soil properties in a tropical Alfisol used for shifting cultivation","authors":"Ranjith B. Mapa,&nbsp;D. Kumaragamage","doi":"10.1016/S0933-3630(96)00015-3","DOIUrl":"10.1016/S0933-3630(96)00015-3","url":null,"abstract":"<div><p>Many lands in the tropics are abandoned after few seasons of shifting cultivation due to loss of soil fertility. There is a great need for characterizing these soils for reforestation or revegetation using conservation farming systems. This study investigate the variability of soil pH, electrical conductivity (EC), clay content, organic C and available P in a tropical Alfisol and its spatial dependence subsequent to shifting cultivation. These parameters were measured in a total of 132 samples obtained from a 45 by 45 m area according to a pre-determined sampling grid. The coefficient of variation for the parameters ranged from 7% to 44%. The variability was assessed by conventional statistical methods and semi-variograms for spatial dependence using geostatistics. All the soil properties except soil pH exhibited spatial dependence at the distances measured. However, EC showed less spatial dependency when compared with clay, organic matter and available P contents. The spatial auto-correlation was strongest for soil organic C, less for clay and EC and least for available P. EC showed a spatial correlation to a highest distance while the organic C showed spatial correlation to a lowest distance. All properties that showed a spatial dependence exhibited high nugget variance. The parameters obtained from the semi-variograms were used to interpolate the values at unmeasured locations using block kriging. It showed that EC is not a limiting factor for crop production in these areas used for shifting cultivation. The organic C levels were low other than in few pockets showing the need in increasing the organic matter contents before cropping again. Available P contents were also limiting where cereals, soybean, maize and grasses which has a low P demand may be included in any conservation farming systems. The field variability obtained by block kriging is useful in applying soil amendments in pockets rather than to the total field to optimize resource use. This study shows the potential of geostatistics in agronomic applications.</p></div>","PeriodicalId":101170,"journal":{"name":"Soil Technology","volume":"9 3","pages":"Pages 187-197"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0933-3630(96)00015-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88143918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of rainfall electrolyte concentration and slope on infiltration and erosion","authors":"K.-H. Kim ,&nbsp;W.P. Miller","doi":"10.1016/S0933-3630(96)00011-6","DOIUrl":"10.1016/S0933-3630(96)00011-6","url":null,"abstract":"<div><p>The quality of water used for irrigation and rainfall simulation studies may affect infiltration and soil erosion rates significantly due to the effect of dissolved salts on flocculation of soil clays. While these effects have been documented on smectitic soils, less information is available for kaolinitic soils, especially as a function of slope gradient. A small runoff pan (0.4 × 0.2 m) study was carried out to evaluate the effect of solution electrolyte content (CaSO₄ · 2H₂O added to give electrical conductivities (EC) = 0, 50, 100, and 200 mS m⁻¹) and slope (9%, 18%, 30%) on runoff, infiltration, and interrill erosion under a rainfall simulator at an intensity of 41 mm h⁻¹. For cultivated topsoils of Appling sandy loam and Davidson clay loam, increasing the EC to 50 mS m⁻¹ decreased the runoff percentage and decreased soil loss, but further increases in EC up to 200 mS m⁻¹ had little effect for either soil. The amount of soil loss reduction due to increased EC was greater at higher slopes for both soils. Soil loss increased significantly as the slope gradient increased at all EC values for both soils. Increasing EC to 50 mS m⁻¹ resulted in elimination of primary clay in sediment for both soils at all slopes, suggesting flocculation of clay was responsible for decreases in runoff and erosion with salt treatment. Flocculation tests on the soils showed 50 mS m⁻¹ as CaSO₄ was sufficient to flocculate the soils, suggesting such a test might predict EC values likely to affect the field behavior of the soils under rainfall.</p></div>","PeriodicalId":101170,"journal":{"name":"Soil Technology","volume":"9 3","pages":"Pages 173-185"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0933-3630(96)00011-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88594874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A two-probe method for measuring water content of thin forest floor litter layers using time domain reflectometry","authors":"Tino Börner ,&nbsp;Mark G. Johnson ,&nbsp;Paul T. Rygiewicz ,&nbsp;David T. Tingey ,&nbsp;Glenn D. Jarrell","doi":"10.1016/S0933-3630(96)00019-0","DOIUrl":"10.1016/S0933-3630(96)00019-0","url":null,"abstract":"<div><p>Few methods exist that allow non-destructive in situ measurement of the water content of forest floor litter layers (Oa, Oe, and Oi horizons). Continuous non-destructive measurement is needed in studies of ecosystem processes because of the relationship between physical structure of the litter and the biological and chemical processes that take place therein. We developed a method using time domain reflectometry (TDR) to monitor water content in a coniferous forest floor litter layer. Litter and mineral soil horizons were reconstructed in test beds in which TDR probes were placed and measurements taken using a range of litter and mineral soil water contents. Two probes are necessary when litter thickness is less than the spatial sensitivity (6 to 8 cm) of the TDR probes; one probe placed in the mineral soil and another one at the interface of the litter and mineral soil. Using this arrangement of TDR probes and simple mathematical relationships, the volumetric water content of forest litter can be estimated continuously. When the results of the two-probe method are compared to volumetric water content of forest litter obtained by gravimetric means there is a strong positive linear relationship between the two measured values of litter water content (<em>r</em>² = 0.93). The two-probe method, however, underestimates litter water at low water contents and overestimates it at high water contents. This error has at least three components: (1) TDR instrument error, (2) errors in estimating volumetric water content from gravimetric data, and (3) using a TDR calibration curve not specific for high organic matter litter layer material. Calibrating the instrument for this specific condition should be improve the overall estimate of the litter layer water content.</p></div>","PeriodicalId":101170,"journal":{"name":"Soil Technology","volume":"9 3","pages":"Pages 199-207"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0933-3630(96)00019-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79014213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil aggregate stability in three Mediterranean environments","authors":"A. Cerdà","doi":"10.1016/S0933-3630(96)00008-6","DOIUrl":"10.1016/S0933-3630(96)00008-6","url":null,"abstract":"<div><p>This paper considers the effect of vegetation on soil aggregate stability in three different Mediterranean landscapes in Southeast Spain. Soils on limestone, marls and clays, with two levels of vegetation cover at each north-facing slopes of the study areas, were investigated. Three aggregate stability tests (CND, TDI and UD) based on the drop impact and ultrasonic dispersion methods and the Emerson dispersion test were performed. The results of the experiments show the positive influence of vegetation on aggregate stability. However, vegetation is less important than lithology in influencing soil aggregate stability. Soil depth and moisture also affect aggregation, but the relationships are different for each soil type. Soil aggregate stability reflects the operation of a highly complex system, in which vegetation, lithology, water content and depth, amongst others, are the main factors.</p></div>","PeriodicalId":101170,"journal":{"name":"Soil Technology","volume":"9 3","pages":"Pages 133-140"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0933-3630(96)00008-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72607931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cover and barrier effect of Cassia siamea hedgerows on soil conservation in semi-arid Kenya","authors":"Paul Kiepe","doi":"10.1016/S0933-3630(96)00010-4","DOIUrl":"10.1016/S0933-3630(96)00010-4","url":null,"abstract":"<div><p>The contribution of <em>Cassia siamea</em> hedgerows and mulch to erosion control was evaluated on a 14% slope of a Lixisol/Alfisol at Machakos, Kenya. The four treatments, in 400 m² runoff-plots were: hedgerows with prunings applied as mulch to the crop, hedgerows and crops with prunings removed, mulch only applied to the crop and a control. The hedgerows were planted on the contour, 4 m apart and 0.25 m between plants. Maize and cowpea were planted in sequence. The control plot sustained an average annual water loss over 3 y of 31 mm runoff and soil loss of 19 t ha⁻¹. The best treatment, hedgerows with mulch, reduced losses to 13% and 2% of the control. Hedgerows without mulch reduced losses respectively to 23% and 7%, while mulch without hedgerows reduced losses to 41% and 17%. Soil loss was considerably influenced by one single storm in April 1990 due to the nature of that storm and to the susceptibility of the soil to erosion at that particular time. Differences in crop yield between treatments were small. The hedgerow treatments depressed cowpea yield slightly in less than normal rainy seasons but improved cowpea yields in wet seasons.</p></div>","PeriodicalId":101170,"journal":{"name":"Soil Technology","volume":"9 3","pages":"Pages 161-171"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0933-3630(96)00010-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75695971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of gypsum on hydrological, mechanical and porosity properties of a kaolinitic crusting soil","authors":"L. Borselli ,&nbsp;S. Carnicelli ,&nbsp;G.A. Ferrari ,&nbsp;M. Pagliai ,&nbsp;G. Lucamante","doi":"10.1016/0933-3630(95)00034-8","DOIUrl":"https://doi.org/10.1016/0933-3630(95)00034-8","url":null,"abstract":"<div><p>Numerous papers have shown the effectiveness of gypsum addition in reducing crust formation on sodic or generally non-acid soils, while the effect on acid soils has been less frequently studied and is less known. The present paper reports the results of a series of field rainfall simulations on an acid red soil (Rhodic Kandiustalf) in Northeast Zimbabwe. In these experiments, gypsum effect on hydrological behaviour in subsequent rainstorms was verified, and the mechanical properties of the crusts so formed were assessed by a modified hand penetrometer. The results showed the ability of gypsum to improve overall infiltration, mostly by reducing the rate of infiltration decay in the non-steady portion of a Horton-type infiltration curve; such rate of infiltration decay was shown to be not constant in subsequent rainstorms, with a well defined increasing trend, that was, however, less marked for gypsum-treated plots. Effect on final infiltration rate was much less significant. Surface crusts formed on gypsum-treated plots were shown to be significantly harder than those formed on untreated plots. Both results could be explained by the observation that a substantial loss of clay from the soil surface took place in untreated plots, while this process was significantly reduced by gypsum treatment. This lesser clay depletion would be effective in slowing structural collapse during wetting, and was also observed to allow the regeneration of a better developed soil structure on drying, so further slowing soil response in subsequent rainstorms. The greater clay content in the surface layer could also induce a higher degree of cohesion, so explaining the greater surface crust strength induced by gypsum treatment.</p></div>","PeriodicalId":101170,"journal":{"name":"Soil Technology","volume":"9 1","pages":"Pages 39-54"},"PeriodicalIF":0.0,"publicationDate":"1996-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0933-3630(95)00034-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91650818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil freezing problem: an exact solution","authors":"M. Ramos ,&nbsp;J. Aguirre-Puente ,&nbsp;R. Posado Cano","doi":"10.1016/0933-3630(95)00033-X","DOIUrl":"https://doi.org/10.1016/0933-3630(95)00033-X","url":null,"abstract":"<div><p>We have studied soil freezing (thawing) processes which exhibit a definite zone of phasechange. By assuming that conduction is the only heat-transfer mechanism in the system, we approach phase-change problems, with thermophysical properties temperature dependent, via an enthalpic formulation. Mathematical formulation leads to a nonlinear boundary-value problem; we obtained an analytic solution to the problem for different geometric shapes by applying a group theory method. Finally, we can use the analytical solution to describe the thermal regime and the position of the free boundary in soil phase-change problems.</p></div>","PeriodicalId":101170,"journal":{"name":"Soil Technology","volume":"9 1","pages":"Pages 29-38"},"PeriodicalIF":0.0,"publicationDate":"1996-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0933-3630(95)00033-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91650814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Partitioning interrill splash and wash dynamics: a novel laboratory approach","authors":"Y. Wan, S. El‐Swaify, R. Sutherland","doi":"10.1016/0933-3630(95)00035-6","DOIUrl":"https://doi.org/10.1016/0933-3630(95)00035-6","url":null,"abstract":"","PeriodicalId":101170,"journal":{"name":"Soil Technology","volume":"19 1","pages":"55-69"},"PeriodicalIF":0.0,"publicationDate":"1996-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87277617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Partitioning interrill splash and wash dynamics: a novel laboratory approach","authors":"Y. Wan ,&nbsp;S.A. El-Swaify ,&nbsp;R.A. Sutherland","doi":"10.1016/0933-3630(95)00035-6","DOIUrl":"https://doi.org/10.1016/0933-3630(95)00035-6","url":null,"abstract":"<div><p>With an innovative experimental device simultaneous measurement of interrill splash and wash on an Oxisol was made at 4, 9, 18, 27, and 36% slopes under a constant rainfall intensity of 65 mm h⁻¹ in a laboratory setting. The specially designed runoff and sediment collection system provided a means of partitioning total splash into directional components (upslope, downslope, and lateral) and interrill sediment transport into wash and splash components. Results indicate that downslope and lateral splash components increased with slope while the upslope component decreased. Overall there was a linear increase of total splash from the 0.18 m² plot with increasing slope. A transport-limited regime prevailed in all studied slopes. The wash process dominated sediment transport at low slopes ( &lt; 9%) and was linearly related to slope with a flux at the steady state ranging from 0.65 g m⁻² min⁻¹ at 4% slope to 3.15 g m⁻² min⁻¹ at 36% slope. Downslope splash transport was dominant at high slopes ( &gt; 9%) and was best described with a power function model (exponent = 1.3) with a flux ranging from 0.33 g m⁻² min⁻¹ at 4% slope to 5.31 g m⁻² min⁻¹ at 36% slope. The WEPP interrill erosion model was inadequate in describing total interrill sediment delivery from the Oxisol. The practical implication of this finding was that splash can be an important process of sediment transport in interrill erosion. Failure to include splashed sediment in interrill erosion measurements using the common “runoff-trough” approach may underestimate total soil loss or interrill sediment delivery to rills.</p></div>","PeriodicalId":101170,"journal":{"name":"Soil Technology","volume":"9 1","pages":"Pages 55-69"},"PeriodicalIF":0.0,"publicationDate":"1996-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0933-3630(95)00035-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91650813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of gypsum on hydrological, mechanical and porosity properties of a kaolinitic crusting soil","authors":"L. Borselli, S. Carnicelli, G. Ferrari, M. Pagliai, G. Lucamante","doi":"10.1016/0933-3630(95)00034-8","DOIUrl":"https://doi.org/10.1016/0933-3630(95)00034-8","url":null,"abstract":"","PeriodicalId":101170,"journal":{"name":"Soil Technology","volume":"40 1","pages":"39-54"},"PeriodicalIF":0.0,"publicationDate":"1996-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89788248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}