Table Of Content

AUTHOR INDEX Canadian Journal of Soil Science, Volume 73, 1993 Adams, B. W., 641 Deering, K. W., 652 Akinremi, O. O., 387 de Jong, E., 81 Al-Kannani, T., 644 deMontigny, L. E., 9 Al-Sammarae, I., 644 Derdour, H., 299 Anderson, D. W., 165, 613 Dickson, E., 647 Angers, D. A., 39, 51, 115, 299, 641, 642, Donald, R. G., 165, 641, 642 645, 655 Dormaar, J. F., 267, 641 Drought, B. G., 103 Bailey, L. D., 243 Dubbin, W. E., 447 Balisky, A. C., 411 Dudas, M. J., 399 Banton, O., 329, 639, 646 Barnes, S. R., 73 Ellert, B. H., 642 Beauchamp, E. G., 253, 421, 539, 567, 639, Entz, T., 641 653 Evenden, W. G., 137 Beke, G. J., 209, 633 Berch, S. M., 640 Fan, M. X., 129, 642 Bergstrom, D. W., 421, 567, 639 Farrell, R. E., 341 Biederbeck, V. O., 243, 555, 640 Feng, Y., 643, 657 Bissonnette, N., 39 Fernandez, I. J., 317 Blackwell, P. S., 649 Freeze, B. S., 267 Blunden, B. G., 649 Freyman, S., 481 Bole, J. B., 503 Friel, J. K., 644 Bolinder, M., 655 Fuller, L. G., 613 Bouman, O. T., 640 Fyles, J. W., 233, 275, 642, 644 Bowman, B. T., 309 Brandt, S., 597 Gangbazo, G., 653 Burton, P. J., 411 Germida, J. J., 341 Buszard, D., 655 Ghanem, 197 Goh, T. B., 656 Cade-Menun, B. J., 640 Grant, C. A., 223 Campbell, C. A., 123, 173, 387, 555, 579, Gregorich, E. G., 642, 647 597, 640, 649 Grevers, M. C. J., 81 Case ¥.- Zs 381, S15 Groenvelt, P. H., 647 Carefoot, J. M., 503 Gupta, U. C., 1, 642 Caron, J., 329 Gupta, V. V. S. R., 341 Carter, M. R., 640, 642 Celano, G., 293 Haderlein, L., 643 Chang, C., 641 Hall, J. W., 141, 469 Chapman, B., 644 Han, S. F., 647 Chen, J. S., 147 Harapiak, J. T., 648 Cluis, D., 653 Harker, K. N., 649 Coen, G. M., 641 Harnish, J. B., 527 Conner, R. L., 503 Haugen-Kozyra, K., 183 Coote, D. R., 381, 515 Hayhoe, H. N., 489 Cover, J., 639 Hilts, S., 643 Curtin, D., 579, 597 Hogue, E. J., 103, 141, 157 Hoyt, P. B., 103 Daigle, J.-Y., 197 Hume, H. B., 650 Daniel, H., 649 Ivany, J. A., 648 Page numbers in boldface refer to abstracts. Izzaurralde, R. C., 643, 651 659 660 CANADIAN JOURNAL OF SOIL SCIENCE Jackson, S. E., 644 N’Dayegamiye, A. N., 27, 115, 645 Janzen, H. H., 133 Neary, A. J., 73 Juma, N. G., 183 Neilsen, D., 103 Johnson, R., 657 Neilsen, G. H., 157 Nielsen, K. E., 459 Nolin, M. C., 381, 515 Kachanoski, R. G., 629 Nérnberg, P., 459 Kingston, D. G. O., 648 Nyborg, M., 183, 649, 651 Kline, R., 469 Klinka, K., 61 O'Halloran, I. P., 233, 275, 359, 371, 644 Kodama, H., 93 Olsen, P. E., 243 Kohut, C. K., 399 Oscarson, D. W., 650 Kolstee, H. W., 527 Kowalenko, C. G., 481 Papadopoulos, Y., 652 Krouse, H. R., 633 Paquet, J. M., 329 Parchomchuk, P., 157 Paul, J. W., 253, 539 Laflamme, L., 652 Paulin, R., 197 Lafond, G. P., 223, 555, 579 Pawluk, S., 209, 633 Lafond, J., 645 Pelletier, F., 645 Lafrance, P., 645, 646 Pelletier, R. G., 489 Larocque, M., 639, 646 Penny, D. C., 649 Laverdiére, M. R., 299, 653 Pesant, A. R., 650 Lavkulich, L. M., 61, 640 Pettapiece, W. W., 650 Lawrence, G. B., 317 Piccolo, A., 293 LeBlanc, P., 197 Pietramellara, G., 293 Légére, A., 39, 51 Pradhan, R., 651 La, YS 647 Preston, C. M., 640 Liang, B. C., 647 Purveen, H., 643 Lindwall, C. W., 267 Liu, W. Z., 647 Longerich, H. P., 644 Qian, H., 61 Lu, S., 349 Rembon, F. S., 651 Rice, W. A., 243 MacKenzie, A. F., 129, 147, 233, 275, 642, Richards, J. E., 197 644, 651, 655, 647 Ridley, A. O., 656 MacLeod, J. A., 642, 648, 652 Roberts, B. A., 651, 652 Mahendrappa, M. K., 648, 653 Rodd, A. V., 527, 652 Makalew, A. M., 647 Roddan, B. H., 141 Malhi, S. S., 648, 649 Ross, G. J., 93 Martineau, S., 645 Rostad, H. P. W., 447 Maynard, D. G., 433 Rustad, L. E., 317 McBride, R. A., 649, 655 McNabb, D. H., 657 Salmins, S., 655 McRae, K., 652 Samson, N., 39, 51 McRae, K. B., 527 Sanderson, J. B., 648, 652 Meier, J. N., 233 Schnitzer, M., 649 Mermut, A. R., 447 Selles, F., 173, 387 Miller, J. J., 209, 633 Sheppard, S. C., 137 Miller, M. H., 349 Sigrist, A., 371 Mitchell, P., 643 Simard, R. R., 27, 645, 646, 653 Monreal, C. M., 133, 642, 649 Slinkard, A. E., 243 Moulin, A. P., 579 Sloth, L., 459 Mumey, G., 649 Sommerfeld, T. G, 641 AUTHOR INDEX St. Croix, R., 656 Walsh, B. D., 655 Stewart, J. W. B., 165 Wang, C., 381, 515, 656 Stout, D. G., 141 Warman, P. R., 656 Webber, C., 267 Tenuta, M., 653 Webber, M. D., 656 Thomas, L., 64, White, I., 654 Titus, B. D., 651, 652, 653, 654 Wiebe, B., 656 Topp, E., 287 Willms, W. D., 641 Topp, G. C., 654, 656 Wilson, R., 652, 656 Townley-Smith, L., 579 Winkleman, G. E., 555 Woodrow, E. F., 656 Ukrainetz, H., 640, 649 Xie, R. J., 275 van Kesteren, R., 654 Xu, J. G., 657 van Ryswyk, A. L., 141 van Vliet, L. J. P., 469, 489 Zebarth, B. J., 481 Veenhof, D. W., 655 Zegelin, S. J., 654 Vigneux, J., 650 Zemmer, R. P:, 1235, 173, 387, 597 Villeneuve, J. P., 645 Zhang, X., 539, 639 Voroney, R. P., 655 SUBJECT INDEX Canadian Journal of Soil Science, Volume 73, 1993 Acadia soils Bedrock dykeland survey, 527 clay mineralogy of parent materials in Acidification southern Saskatchewan, 447 effect of fertigation on soil acidification, 157 Bicarbonate-extractable P Acidulation materials overwinter changes in Olsen P, 123 oxidation of S and acidulation of calcareous response of soil and grain to regular P soils, 103 applications, 173 Agar Bicarbonate-soluble Pi measuring pH changes in fertilizer deep distribution of Olsen-P in soil, 555 microsites, 129 Biogenic opal Aggregation forest invasion of prairie soils, 613 management-induced changes in water-stable Boundary line aggregation, 51 an empirical model of denitrification, 421 Agrochemicals Bulk density effects of agrochemicals on methane tillage and rotations on soil physical oxidation, 287 properties, 223 Air-filled porosity denitrification rate and determinant soil Calcium dissolution properties, 567 ammonium lignosulphonate and phosphate Alfalfa reactions, 275 cobalt content of crops, | Carbohydrate soil properties and winter survival, 141 management-induced changes in organic Aluminum matter, 39 extractable iron and aluminum in soils, 73 Carbon Amelioration nitrogen mineralization, 27 soil structure and crop yield following Carbon-13 NMR subsoiling, 81 humus types from two ecosystem phases, 9 Ammonia volatilization Carbon dioxide evolution lignosulfonate-fertilizer effects on N the influence of hexazinone on carbon dynamics, 233 dioxide evolution, 433 Animal manure Cation leaching availability of nitrogen in manure for corn, effect of fertigation on soil acidification, 157 Z33 Cesium-137 Animal wastes '7Cs use to investigate net soil erosion, 515 economics of manure application, 267 estimating soil loss from changes in soil Aspen Parkland cesium-137, 629 forest invasion of prairie soils, 613 short-range variability of fallout '"’Cs, 381 Available P Chemistry overwinter changes in Olsen P, 123 salinization at two sites in Alberta, 209 Available water storage capacity Chernozemic smectite soil properties and winter survival, 141 x-ray diffraction characteristics of soil smectites, 93 Barley Clay cobalt content of crops, 1 particle size separates, 137 ground covers in raspberry production, 481 Clay mineralogy N cycling under conventional and zero clay mineralogy of parent materials in tillage, 183 southern Saskatchewan, 447 Climate soil color-nitrogen relationship, 61 Closed basin Page numbers in boldface refer to abstracts. salinization at two sites in Alberta, 209 662 SUBJECT INDEX Clover (white) Denitrifying enzyme activity ground covers in raspbery production, 481 denitrification rate and determinant soil Cobalt properties, 567 cobalt content of crops, 1 Deposition Cold hardiness '57Cs use to investigate net soil erosion, 515 soil properties and winter survival, 141 Diammonium phosphate Cold-wet dichromate digestion lignosulfonate-fertilizer effects on N organic-C dynamics in a Dark Brown dynamics, 233 Chernozem, 133 Dinitrogen fixation Conservation replacing summerfallow with annual legume '57Cs use to investigate net soil erosion, 515 green manure, 243 replacing summerfallow with annual legume Dithionite green manure, 243 extractable iron and aluminum in soils, 73 Contaminant Diurnal pattern particle size separates, 137 plant species effects on soil temperature, 411 Conventional tillage Dry combustion effects of management on soil P organic-C dynamics in a Dark Brown fractionation, 359 Chernozem, 133 Corn Dry sieving effectiveness of organo-mineral fertilizers, soil aggregation in Black Chernozemic soils, 197 579 urea and KCI placement for corn, 147 soil aggregate stability in Brown soils, 597 Corn yield Dykeland availability of nitrogen in manure for corn, dykeland survey, 527 253 Crop growth soil structure and crop yield following Electrical conductivity subsoiling, 81 oxidation of S and acidulation of calcareous Crop rotation soils, 103 fertilization and nitrate leaching, 387 Eroded soil overwinter changes in Olsen P, 123 economics of manure application, 267 response of soil and grain to regular Erodibility P applications, 173 soil aggregate stability in Brown soils, 597 soil aggregate stability in Brown soils, 597 Erosion tillage and rotations on soil physical '57Cs use to investigate net soil erosion, 515 properties, 223 Erosion plots Crystallinity tillage effects on runoff and soil loss, 469 X-ray diffraction characteristics of soil Erosion rate smectites, 93 estimating soil loss from changes in soil CuO oxidation cesium-137, 629 humus types from two ecosystem phases, 9 Evaporite mineralogy and trace elements of salt- Decomposition _ affected soils, 399 humus types from two ecosystem phases, 9 Extractable soil potassium Degradation soil properties and winter survival, 141 fate of '4C-metolachlor and atrazine in field lysimeters, 309 Denitrification Feedlot manure denitrification rate and determinant soil economics of manure application, 267 properties, 567 Fertigation nitrous and nitric oxide emissions from effect of fertigation on soil acidification, 157 manured soil, 539 Fertilization Denitrification rate soil aggregation in Black Chernozemic soils, an empirical model of denitrification, 421 579 664 CANADIAN JOURNAL OF SOIL SCIENCE Fertilizer Hexazinone availability of nitrogen in manure for corn, the influence of hexazinone on carbon 253 dioxide evolution, 433 deep distribution of Olsen-P in soil, 555 HI-reducible S measuring pH changes in fertilizer activity of arylsulfatase in Saskatchewan microsites, 129 soils, 341 Fertilizer economics Hordeum vulgare (L.) (See Barley) economics of manure application, 267 Horizon development Fertilizer efficiency forest soil properties and landscape lignosulfonate-fertilizer effects on N morphology, 165 dynamics, 233 Humic acids Fertilizer N wood residue application and soil organic fertilization and nitrate leaching, 387 matter, 115 Fertilizer N recovery Humic substances fertilizer N timing for irrigated spring wheat, iron humates and FE extractants in the 503 rhyzospere, 293 Fertilizer N timing Humins fertilizer N timing for irrigated spring wheat, wood residue application and soil organic 503 matter, 115 Fertilizer placement Humus urea and KCI placement for corn, 147 humus types from two ecosystem phases, 9 Forest invasion Hydrology forest invasion of prairie soils, 613 salinization at two sites in Alberta, 209 Forest soil soil mass and nutrients under spruce fir Illuviation forest, 317 forest soil properties and landscape the influence of hexazinone on carbon morphology, 165 dioxide evolution, 433 Forest soil color Inhibition effects of agrochemicals on methane soil color-nitrogen relationship, 61 oxidation, 287 Fourier analysis Iron plant species effects on soil temperature, 411 extractable iron and aluminum in soils, 73 iron humates and FE extractants in the rhyzospere, 293 Geometric mean diameter Irrigation fertilizer N timing for irrigated spring wheat, soil aggregate stability in Brown soils, 597 503 soil aggregation in Black Chernozemic soils, 579 Geomorphology Leaching forest soil properties and landscape fate of '*C-metolachlor and atrazine in field morphology, 165 lysimeters, 309 Gompertz equation Legume nitrogen mineralization, 27 deep distribution of Olsen-P in soil, 555 Grain soil aggregation in Black Chernozemic soils, urea and KCI placement for corn, 147 579 Green manure Legume plow-down deep distribution of Olsen-P in soil, 555 replacing summerfallow with annual legume Grinding green manure, 243 extractable iron and aluminum in soils, 73 Light and heavy fractions wood residue application and soil organic matter, 115 Herbicide Lignosulfonate fate of '*C-metolachlor and atrazine in field lignosulfonate-fertilizer effects on N lysimeters, 309 dynamics, 233 SUBJECT INDEX 665 Line potential Mobility ammonium lignosulphonate and phosphate fate of '4C-metolachlor and atrazine in field reactions, 275 lysimeters, 309 Liquid hog manure Model manure incubation with monocalcium an empirical model of denitrification, 421 phosphate, 371 Monocalcium phosphate Low-temperature injury manure incubation with monocalcium soil properties and winter survival, 141 phosphate, 371 Luvisol forest soil properties and landscape Nitrate leaching morphology, 165 effectiveness of organo-mineral fertilizers, 197 Maize fertilization and nitrate leaching, 387 phosphorous placement for maize, 349 Nitrate-N Management replacing summerfallow with annual legume management-induced changes in organic green manure, 243 matter, 39 Nitrate test management-induced changes in water-stable availability of nitrogen in manure for corn, aggregation, 51 253 Manure Nitric oxide availability of nitrogen in manure for corn, nitrous and nitric oxide emissions from 253 manured soil, 539 economics of manure application, 267 Nitrification effects of management on soil P lignosulfonate-fertilizer effects on N fractionation, 359 dynamics, 233 manure incubation with monocalcium nitrous and nitric oxide emissions from phosphate, 371 manured soil, 539 nitrous and nitric oxide emissions from manured soil, 539 Nitrogen replacing summerfallow with annual legume soil color-nitrogen relationship, 61 green manure, 243 the influence of hexazinone on carbon Manure-fertilizer mixtures dioxide evolution, 433 manure incubation with monocalcium Nitrogen availability phosphate, 371 availability of nitrogen in manure for corn, Medicago sativa L. (See Alfalfa) 253 Meteorological conditions Nitrogen fertilizer soil aggregate stability in Brown soils, 597 effect of fertigation on soil acidification, 157 Methane oxidation Nitrogen-15 effects of agrochemicals on methane N cycling under conventional and zero oxidation, 287 tillage, 183 Microbial biomass Nitrogen recovery activity of arylsulfatase in Saskatchewan N cycling under conventional and zero soils, 341 tillage, 183 management-induced changes in organic Nitrogen uptake matter, 39 fertilization and nitrate leaching, 387 Microclimate Nitrogenation plant species effects on soil temperature, 41 | fertilizer N timing for irrigated spring wheat, Microsite 503 measuring pH changes in fertilizer Nitrous oxide microsites, 129 nitrous and nitric oxide emissions from Mineralogy manured soil, 539 mineralogy and trace elements of salt- No-till affected soils, 399 effects of management on soil P salinization at two sites in Alberta, 209 fractionation, 359 666 CANADIAN JOURNAL OF SOIL SCIENCE Oat Phosphatase cobalt content of crops, 1 management-induced changes in organic Olsen P matter, 39 response of soil and grain to regular P Phosphate potential applications, 173 ammonium lignosulphonate and phosphate Organic acids reactions, 275 iron humates and FE extractants in the Phosphate precipitation rhyzospere, 293 ammonium lignosulphonate and phosphate Organic carbon reactions, 275 activity of arylsulfatase in Saskatchewan Phosphorus soils, 341 overwinter changes in Olsen P, 123 organic-C dynamics in a Dark Brown the influence of hexazinone on carbon Chernozem, 133 dioxide evolution, 433 wood residue application and soil organic Phosphorus absorption matter, 115 phosphorous placement for maize, 349 Organic matter Phosphorus fractionation dykeland survey, 527 effects of management on soil management-induced changes in organic P fractionation, 359 matter, 39 manure incubation with monocalcium N cycling under conventional and zero phosphate, 371 tillage, 183 Phosphorus piacement nitrogen mineralization, 27 phosphorous placement for maize, 349 Organo-mineral fertilizers Phosphorus uptake effectiveness of organo-mineral fertilizers, mantire incubation with monocalcium 197 phosphate, 371 Oxalate Plant chlorosis extractable iron and aluminum in soils, 73 iron humates and FE extractants in the Oxygen isotopes rhyzospere, 293 sulfur and oxygen isotopes of sulfates, 633 Podzolic smectite Parent materials X-ray diffraction characteristics of soil clay mineralogy of parent materials in southern Saskatchewan, 447 smectites, 93 Particle size Porosité de retrait espace poral et travail du sol, X-ray diffraction characteristics of soil Porosité structurale smectites, 93 Particle thickness espace poral et travail du sol, X-ray diffraction characteristics of soil Porosité texturale smectites, 93 espace poral et travail du sol, Peat substrates Porosité totale water desorption characteristics of peat espace poral et travail du sol, 299 substrates, 329 Potassium chloride Peak intensity urea and KCI placement for corn, 147 X-ray diffraction characteristics of soil Potentially mineralizable N smectites, 93 nitrogen mineralization, 27 Penetration resistance Prairie-forest transition tillage and rotations on soil physical forest invasion of prairie soils, 613 properties, 223 Precipitation Perennial ryegrass response of soil and grain to regular P ground covers in raspberry production, 481 applications, 173 pH Prediction measuring pH changes in fertilizer estimating soil loss from changes in soil microsites, 129 cesium-137, 629 Phenolic compounds Pyrophoshate sandy soil changes caused by vegetation, 459 extractable iron and aluminum in soils, 73 SUBJECT INDEX 667 Quantitative pits Slaking soil mass and nutrients under spruce fir management-induced changes in water-stable forest, 317 aggregation, 51 Snow management Radioisotope fertilization and nitrate leaching, 387 fate of '*C-metolachlor and atrazine in field Snowmelt lysimeters, 309 snowmelt runoff, 489 Reduced-tillage Sodium effects of management on soil P dykeland survey, 527 fractionation, 359 Soft white wheat Regression analysis fertilizer N timing for irrigated spring wheat, soil color-nitrogen relationship, 61 503 Resistance to penetration Soil acidification dykeland survey, 527 effect of fertigation on soil acidification, 157 Root growth Soil conservation phosphorous placement for maize, 349 '7Cs use to investigate net soil erosion, 515 Rotation replacing summerfallow with annual legume deep distribution of Olsen-P in soil, 555 green manure, 243 Runoff Soil depth snowmelt runoff, 489 forest soil properties and landscape tillage effects on runoff and soil loss, 469 morphology, 165 Soil loss tillage effects on runoff and soil loss, 469 Salal Soil management humus types from two ecosystem phases, 9 management-induced changes in organic Salinity matter, 39 mineralogy and trace elements of salt- management-induced changes in water-stable affected soils, 399 aggregation, 51 Salinization Soil methane oxidation salinization at two sites in Alberta, 209 effects of agrochemicals on methane sulfur and oxygen isotopes of sulfates, 633 oxidation, 287 Salt Soil moisture dykeland survey, 527 replacing summerfallow with annual legume Sample size green manure, 243 soil mass and nutrients under spruce fir soil color-nitrogen relationship, 61 forest, 317 Soil moisture budget Sand snowmelt runoff, 489 particle size separates, 137 Soil nitrate test Season availability of nitrogen in manure for corn, tillage effects on runoff and soil loss, 469 253 Sedimentation Soil nitrogen particle size separates, 137 soil color-nitrogen relationship, 61 Sheep’s fescue Soil organic matter ground covers in raspberry production, 481 nitrogen mineralization, 27 Short-range variability ; Soil pH short-range variability of fallout '"’Cs, 381 forest soil properties and landscape Side-hill seep morphology, 165 salinization at two sites in Alberta, 209 oxidation of S and acidulation of calcareous Siderophores soils, 103 iron humates and FE extractants in the Soil quality rhyzospere, 293 management-induced changes in organic Silt matter, 39 particle size separates, 137 nitrogen mineralization, 27 Size fractionation Soil temperature particle size separates, 137 plant species effects on soil temperature, 411 668 CANADIAN JOURNAL OF SOIL SCIENCE Soil testing Time domain reflectometry overwinter changes in Olsen P, 123 water desorption characteristics of peat Soil texture substrates, 329 nitrogen mineralization, 27 Timothy soil color-nitrogen relationship, 61 cobalt content of crops, 1 Soil water Trace elements soil structure and crop yield following mineralogy and trace elements of salt- subsoiling, 81 affected soils, 399 Soil-landscape relationship Travail du sol forest invasion of prairie soils, 613 espace poral et travail du sol, 299 Spodosols Triple superphosphate sandy soil changes caused by vegetation, 459 measuring pH changes in fertilizer Spruce-fir microsites, 129 soil mass and nutrients under spruce fir Typic cryoboroll forest, 317 N cycling under conventional and zero Subsoiling tillage, 183 soil structure and crop yield following subsoiling, 81 Sulfates Uppermost Cretaceous sulfur and oxygen isotopes of sulfates, 633 clay mineralogy of parent materials in Sulfur southern Saskatchewan, 447 activity of arylsulfatase in Saskatchewan Urea soils, 341 measuring pH changes in fertilizer the influence of hexazinone on carbon microsites, 129 dioxide evolution, 433 lignosulfonate-fertilizer effects on N Sulur incubation dynamics, 233 urea and KCI placement for corn, 147 oxidation of S and acidulation of calcareous soils, 103 Sulfur isotopes Vegetation effects sulfur and oxygen isotopes of sulfates, 633 plant species effects on soil temperature, 411 Sulfur oxidation Vegetation-induced soil changes oxidation of S and acidulation of calcareous sandy soil changes caused by vegetation, 459 soils, 103 Tannin Water characteristics humus types from two ecosystem phases, 9 water desorption characteristics of peat Temperature effects substrates, 329 plant species effects on soil temperature, 411 Water erosion response of soil and grain to regular P short-range variability of fallout '*’Cs, 381 applications, 173 Water release curve Tertiary water desorption characteristics of peat clay mineralogy of parent materials in substrates, 329 southern Saskatchewan, 447 Water-stable aggregates Testing wood residue application and soil organic overwinter changes in Olsen P, 123 matter, 115 Texture Wet aggregate stability nitrogen mineralization, 27 ground covers in raspberry production, 481 soil color-nitrogen relationship, 61 Wet sieving Tillage soil aggregation in Black Chernozemic soils, effects of management on soil P fractionation, 579 359 soil aggregate stability in Brown soils, 597 N cycling under conventional and zero tillage, 183 Wheat tillage and rotations on soil physical cobalt content of crops, | properties, 223 fertilizer N timing for irrigated spring wheat, tillage effects on runoff and soil loss, 469 503