Agronomy D VA N C E S VOLUME I N 69 Advisory Board Martin Alexander Ronald Phillips Cornell University University of Minnesota Kenneth J Frey Larry P Wilding Iowa State University Texas A&M University Prepared in cooperation with the American Society of Agronomy Monographs Committee John Bartels Jerry M Bigham Jerry L Hatfield David M Krell Diane E Stott, Chairman Linda S Lee David Miller Matthew J Morra John E Rechcigl Donald C Reicosky Wayne F Robarge Dennis E Rolston Richard Shibles Jeffrey Volenec Agronomy DVANCES IN VO L U M E 69 Edited by Donald L Sparks Department of Plant and Soil Sciences University of Delaware Newark, Delaware San Diego San Francisco New York Boston London Sydney Tokyo COPYRIGHT PAGE SUPPLIED BY AP Contents Contributors Preface vii ix THE MEASUREMENT AND INTERPRETATION OF SORPTION AND DESORPTION RATES FOR ORGANIC COMPOUNDS IN SOIL MEDIA Joseph J Pignatello I II III IV V VI Introduction The Nature of Elementary Sorption Processes in Soils Slow Sorption and Desorption Sorption Kinetic Models Experimental Methods Sorption Kinetics and Bioavailability References 16 27 45 56 65 ENVIRONMENTAL INDICATORS OF AGROECOSYSTEMS O H Smith, G W Petersen, and B A Needelman I II III IV V VI VII Introduction Agroecosystems Monitoring and Assessment Endpoints Environmental Indicators Soil Organic Matter as a Candidate Environmental Indicator Indicator Ranking Conclusions and Recommendations References 76 76 77 78 85 90 91 92 GROWTH PROMOTION OF PLANTS INOCULATED WITH PHOSPHATE-SOLUBILIZING FUNGI M A Whitelaw I Introduction II Soil Phosphorus III Phosphate-Solubilizing Soil Microorganisms IV Liquid Medium Studies v 100 100 106 109 vi CONTENTS V Plant Growth Promotion by Phosphate-Solubilizing Fungi VI Conclusion References 133 143 144 HYDROLOGICAL FACTORS FOR PHOSPHORUS TRANSFER FROM AGRICULTURAL SOILS P M Haygarth, A L Heathwaite, S C Jarvis, and T R Harrod I Introduction II Temporal Variables III Spatial Variables IV Conclusions References 154 155 162 173 173 CASSAVA, Manihot esculenta Crantz, GENETIC RESOURCES: THEIR COLLECTION, EVALUATION, AND MANIPULATION Nagib M A Nassar I Wild Taxa of Cassava Manihot Species II Broadening the Genetic Base of Cassava, M esculenta Crantz, and Development of Interspecific Hybridization III Development and Selection for Apomixis in Cassava, M esculenta Crantz IV Production of Polyploid Types V Protein Contents in Cassava Cultivars and Its Hybrid with Wild Manihot Species References 180 Index 231 198 210 215 225 227 Contributors Numbers in parentheses indicate the pages on which the authors’ contributions begin T R HARROD (153), Soil Survey and Land Research Centre, Cranfield University, North Wyke, Okehampton, Devon EX20 2SB, United Kingdom P M HAYGARTH (153), Institute of Grassland and Environmental Research, North Wyke, Okehampton, Devon EX20 2SB, United Kingdom A L HEATHWAITE (153), Department of Geography, University of Sheffield, Sheffield S10 2TN, United Kingdom S C JARVIS (153), Institute of Grassland and Environmental Research, North Wyke, Okehampton, Devon EX20 2SB, United Kingdom NAGIB M A NASSAR (179), Departamento de Genética e Morfologia, Universidade de Brasília, Brasília 70919, Brazil B A NEEDELMAN (75), Department of Agronomy, Pennsylvania State University, University Park, Pennsylvania 16802 G W PETERSEN (75), Department of Agronomy, Pennsylvania State University, University Park, Pennsylvania 16802 JOSEPH J PIGNATELLO (1), The Connecticut Agricultural Experiment Station, New Haven, Connecticut 06511 O H SMITH (75), Department of Agronomy, Pennsylvania State University, University Park, Pennsylvania 16802 M A WHITELAW (99), School of Wine and Food Sciences, Charles Sturt University, Wagga Wagga, New South Wales 2678, Australia vii This Page Intentionally Left Blank Preface Volume 69 contains five excellent reviews dealing with crop and soil sciences Chapter is a comprehensive and timely review on the measurement and interpretation of sorption and desorption rates for organic compounds in soil media Topics covered include the nature of elementary sorption processes in soil, hindered sorption and desorption processes, sorption kinetic models, experimental methods, and sorption kinetics and bioavailability Chapter 2, by O H Smith and co-workers, is an excellent overview of environmental indicators of agroecosystems Soil organic matter content is discussed in detail as a candidate environmental indicator A ranking scheme is proposed for the use of multiple indicators in decision-making applications Chapter 3, by M A Whitelaw, is an interesting treatise on plant growth as affected by phosphate-solubilizing soil microorganisms The author provides a discussion on soil phosphorus, studies on P-solubilizing soil microorganisms, aspects of liquid medium studies, and plant growth promotion by phosphate-solubilizing fungi Chapter 4, by P M Haygarth et al., is a fine review on hydrological factors affecting phosphorus (P) transfer from agricultural soils The authors review current knowledge to define the spatial and temporal controls on P transfer from agricultural soils via the various hydrological pathways Chapter 5, by N M A Nassar, provides a thorough treatment of Cassava, Manihot esculenta Crantz, genetic resources Topics that are discussed include wild taxa, the genetic base and development of interspecific hybrids, development and selection for apomixis, production of polyploid types, and protein content in cultivars Many thanks to the authors for their first-rate contributions Donald L Sparks ix 224 NAGIB M A NASSAR Table XXV Average Productivity per Plant of the Triploid (Selection 121) and Other Cassava Clones under Savanna and Semiarid Conditions Clone Triploid 121 Sonora Triploid 121 Nagib 01/84 Nagib 02/84 Nagib 03/84 Nagib 04/84 Cigana No plants Productivity 30 30 29 27 29 28 22 28 2.13 1.67 5.9 1.8 3.7 1.1 4.1 2.9 Region, location of trial, and harvest age (kg/plant) Central Brazil, conducted at the experimental station, Univ of Brasília; harvest age 12 months Under semiarid conditions; trial conducted by the CPATS, Petrolina, northeastern Brazil; harvest age 18 months Mendiburu and Peloquin (1977) proposed parallel spindle as an additional mechanism The 2n pollen mutations were described in several plant species: Zea mays (Roads and Dempsey, 1966), Solanum (Hogland, 1970), Medicago sativa (Vorsa and Bingham, 1979), and Lolium (Sala et al., 1989) The vigor of Nassarselected triploid as seen in its productivity both under central Brazil conditions and in the semiarid tropics adds evidence of the usefulness of this 2n gamete phenomenon as a powerful mechanism for transferring variability and fitness to polyploid offspring If a partially fertile type of triploid could be produced, it will serve in establishing a founder population of a new chromosome race Its progeny may rehybridize with new polyploids and diverse genotypes, producing additive heterotic potentialities Since trivalent occurrence in this triploid is predominantly demonstrating gene exchange between wild and cultivated genomes, it is likely that this will generate more variability in the progeny The wild parent and its interspecific hybrid progeny are highly tolerant to drought as indicated by their deep roots They normally survive the frequent years of drought in their natural habitat This triploid is a potential progenitor of cultivars adapted to these conditions Table XXVI Chromosome Associations at Metaphase I in the Triploid and Its Parent Average chromosome association Type Natural hybrid Triploid No PMCs examined 50 30 III II I — 10.2 18 9.2 — 3.6 CASSAVA, M esculenta Crantz, GENETIC RESOURCES 225 V PROTEIN CONTENTS IN CASSAVA CULTIVARS AND ITS HYBRID WITH WILD Manihot SPECIES Tubers of 16 cassava clones, months old and maintained in the germplasm collection at the Experimental Station, University of Brasília, were analyzed chemically for protein content Total nitrogen and dry matter basis were determined by the 1970 AOAC procedures (Nassar and Dorea, 1982) Percent protein was obtained by multiplying percent N by the factor 6.25 For every clone two samples were analyzed, one from a small tuber (50 g) and the second from older tubers (200 g) Tubers were peeled, and protein was estimated in the coth peel and pulp Tubers of hybrid between cassava clone Catelo and M oligantha were analyzed in the same way Seed of cassava and wild Manihot species maintained in the living collection at the University of Basília were analyzed for protein content by the same procedures The concentration of protein in tubers of cassava clones and tubers of the hybrid is presented in Table XXVII It can be seen that protein percent (N% ϫ 6.25 ϭ protein percent) ranged from 0.7 to 1.2% for larger tubers (Ͼ200 g), whereas the range was 0.9 to 1.4% for tubers Ͻ50 g In the same clone, protein content of the pulp was higher in small tubers than in larger ones These data agree with those found by Akinrele (1964), who reported 0.7% for protein content in peeled tuber on a dry matter basis, and Chada (1961), who found 1.2% However, these researchers did not pay attention to the effect of tuber size on protein content Jennings (1959) stated that protein in cassava root tends to be concentrated in the outer zone of the root This may explain why the small tubers have higher protein content since they have a larger proportion of the outer zone than the older and larger ones The very little variation of protein content among the 16 clones collected throughout Brazil shows that selection for this characteristic in cassava clones will not bring any notable improvement From Table XXVII it can also be seen that protein is higher in peel than in pulp in all the examined samples and in all clones This may be explained by the previously mentioned statement of Jennings that protein in cassava roots tends to be concentrated in the outer layers The analysis of hybrid tubers showed a notable increase in the hybrid of cassava with M oligantha at 4.6% In an earlier paper (Nassar and Costa, 1978), the protein content in M oligantha was reported to be 7.1% on a dry matter basis Moreover, crosses of this species with cassava were highly fertile (Nassar, 1980) Nassar and Fitchner (1978) also showed a low HCN content in the wild species M oligantha This may exclude any possibility that high protein content in the species is due to HCN nitrogen Table XXVIII shows the results of seed analysis of some wild Manihot species maintained in our living collection The highest protein content is that of M Brachyandra followed by M alutacea 226 NAGIB M A NASSAR Table XXVII Protein Content of Tubers of Cassava Clones Clone CBM 0206 EAB 348 BGM 188 CPM 0231 CPM 2002 CPM 0232 BGM 808 CPM 0225 BGM 204 CPM 1805 EAB 1156 EAB 484 BGM 048 BGM 020 CPM 1060 EAB 675 Hybrid Approximate size (g) Protein in peel (%) Protein in pulp (%) 200 50 200 50 200 50 200 50 200 50 200 50 200 50 200 50 200 50 200 50 200 50 200 50 200 50 200 50 200 50 200 50 200 50 2.13 2.09 1.41 1.69 — 1.68 — 1.56 — 2.08 2.00 1.82 1.63 — 1.38 1.25 1.24 — 1.14 1.37 1.58 1.28 1.96 — 1.41 1.11 1.80 1.53 — 1.58 1.36 1.51 6.63 8.06 0.90 1.22 0.85 1.04 — 1.45 — 1.26 — 0.99 1.02 1.15 0.93 — 0.89 0.95 1.06 — 0.72 1.00 0.84 1.16 1.07 — 0.82 1.17 0.98 1.23 — 1.19 0.70 0.93 4.56 4.56 Manihot brachyandra is native to western Pernambuco and northern Bahia, two of the driest areas in Brazil Nassar (1980) reported that seed of wild cassava is eaten by the population of these regions particularly in times of famine Jones (1959) reported that cassava seed is eaten in several parts of west and central Africa Thus, the discovery of the high protein content in native cassava hybrids may open a new door to better protein-balanced food for people of the tropical world CASSAVA, M esculenta Crantz, GENETIC RESOURCES 227 Table XXVIII Protein Content in Wild Manihot Species Seed on Dry Matter Basis Species Protein% M glaziovii M caerulescens M brachyandra M pseudoglaziovii M alutacea M zenhtneri M dichotoma M reptans M esculenta 30.09 27.91 35.35 31.15 37.33 28.99 29.24 33.25 26.81 ACKNOWLEDGMENT The living collection of wild Manihot species was established at the Universidade de Brasília with the help of the International Development Research Center Ottawa, Ontario, Canada, for which the author is grateful REFERENCES Abraham, A (1975) Breeding of tuber crops in India J Genet Plant Breeding 17, 212–217 Abraham, A., Panicher, P K., and Mathew, P M (1964) Polyploids in relation to breeding in tuber crops J Indian Bot Soc 43, 278 –283 Akinrele, I A., Collins, C., Cook, A S., Hogate, R A., Junaid, Y., and Baumer, G (1962) Pilot plant (1 ton a day) results of month trial run, Research Reprints, Vol 13, pp 1– 30 Federal Institute of Industrial Research, Nigeria Anonymous (1968) Tabla de composicion de pastes y otros alimentos de Centro America, Publication No E-440 Instituto Nacional de Centro America e Panama Asker, S (1979) Progress in apomixis research Hereditas 91, 231–240 Asker, S (1980) Gametophytic apomixis: Elements and genetic regulation Hereditas 93, 277–293 Bolhuis, G G (1953) A survey of some attempts to breed cassava varieties with a high content of proteins in the roots Euphytica 20, 107–112 Brewer, J L., and Henstra, S (1974) Pollen of Pyrethrum Fine structure recognition Euphytica 23, 567–663 Brown, W V., and Emery, W H P (1958) Apomixis in the Gramineae: Panicoideae Am J Bot 45, 253–263 Chada, Y R (1961) Sources of starch in Commonwealth territories III Cassava Trop Sci 3, 101–113 Clement, W M., Jr., and Stanford, E M (1961) A mechanism for the production of tetraploid and pertoploid progeny from diploid and tetraploid cross alfafa Crop Sci 1, 11–14 Cruz, N D (1968) Citologia no gờnero Manihot Adans Determinaỗóo número de cromossomo em algumas espécies anal Acad Bras Ci 40, 81– 95 228 NAGIB M A NASSAR de Wet, J M J (1980) Origin of polyploids In “Polyploidy: Biological Relevance” (W H Lewis, Ed.) Plenum, New York Dione, L A (1963) Studies on the use of Solanum acaule as a bridge between Solanum tuberosum and species in the series Bulbocastana, cardiophylla and Pinnatisecta Euphytica 12, 263 –269 Dobzhansky, T (1973) Genộtica processo evolutivo In Traduỗóo de Celso Abbade Mourão.” Poligono, São Paulo, Brazil Doyle, J J., and Doyle, J L (1987) Isolation of plant DNA from fresh tissues Focus 12, 13 –15 Food and Agriculture Organization (FAO) (1994) “Production Yearbook.” FAO, Rome Graner, E A (1942) Genet Manihot Braganita 2, 13 –19 Grattapaglia, D., and Sederoff, R R (1994) Genetic linkage maps of Eucalyptus grandis and E uroplylla using a pseudo-testcross strategy and RAPD markers Genetics 137, 1121–1137 Grattapaglia, D E., Nassar, N M A., and Dianese, J (1986) Biossistemática de espécies brasileiras Gênero Manihot baseada em padrões de proteína da semente Ciencia Cultura (J Brazilian Assoc Advancement Sci) 19(3), 294 – 300 Grattapaglia, D., Costa e Silva, C., and Nassar, N M A (1996) Strict maternal inheritance of RAPD fingerprints confirm apomixis in cassava (Manihot esculenta Crantz) Can J Plant Sci 76, 379–382 Gustafsson, A (1946) Apomixis in higher plants Part The mechanisms of apomixis Lunds Univ Arsskr Adv 42, 1– 66 Hahn, S K., Bai, K V., and Asiedu, R (1990) Tetraploids, triploids and 2n pollen from diploid interspecific crosses with cassava Theor Appl Genet 79, 433 – 439 Harlan, J (1961) Geographic origin of plants useful to agriculture Am Assoc Adv Sci 66, – Harlan, J R., and de Wet, J M J (1975) On O wings and a prayer; The origins of polyploids Bot Rev 41, 361–390 Hogland, M (1970) Meiosis in Solomum phureja Jereditas 66, 183 –188 Jennings, D L (1959) Manihot melanobasis Muell Arg.—A useful parent for cassava breeding Euphytica 8, 157–162 Knox, R B., Willing, R R., and Prior, L D (1972) Interspecific hybridization in populus using recognitioin pollen Silvae Genet 21, 263 –298 Laemilli, U K (1970) Cleavage of structural proteins during assembly of the head of bacteriophage T4 Nature 227, 680 – 685 Lanjouw, J (1939) Two interesting species of Manihot L from Surinam recueil Travaux Botaniques Neerlandais 36, 542– 549 Magoon, M L., Jos, J S., and Appan, S G (1966) Cytomorphology of interspecific hybrid between cassava and ceara rubber Chromosome Information Service (Japan), pp –10 Mendiburu, A O., and Peloquin, S J (1977) The significance of 2n gametes in potato breeding Theor Appl Genet 49, 53 – 61 Mok, D W K., and Peloquin, S S (1975) The inheritance of three mechanisms of diploandroid (2n pollen) formation in diploid potatoes Heredity 35, 295 – 302 Narty, F (1969) Studies on cassava, Manihot utilissima Pohl Cyanogenesis: The biosynthesis of linamarin and lutaustalin in etioled seedlings Phytochemistry 7, 1307–1312 Nassar, N M A (1978a) Genetic resources of cassava: Chromosome behavior in some Manihot species Indian J Genet Plant Breeding 38, 135 –137 Nassar, N M A (1978b) Conservation of the genetic resources of cassava (Manihot esculenta); Determination of wild species localities with emphasis on probable origin Econ Bot 32, 311– 320 Nassar, N M A (1978c) Microcenters of wild cassava Manihot spp diversity in central Brazil Turrialba 28(4), 345 – 347 Nassar, N M A (1978d) Hydrocyanic acid content in some wild Manihot (cassava) species Can J Plant Sci 58, 577– 578 Nassar, N M A (1978e) Some further species of Manihot with potential value to cassava breeding Can J Plant Sci 58, 915 – 916 CASSAVA, M esculenta Crantz, GENETIC RESOURCES 229 Nassar, N M A (1978f ) Wild Manihot species of central Brazil for cassava breeding Can J Plant Sci 58, 257–261 Nassar, N M A (1979a) A study of the collection and maintenance of the germoplasm of wild cassavas Manihot spp Turrialba 29(3), 221 Nassar, N M A (1979b) Three brazilian Manihot species with tolerance to stress conditions Can J Plant Sci 59, 533– 555 Nassar, N M A (1980a) Attempts to hybridize wild Manihot species with cassava Econ Bot 34, 13–15 Nassar, N M A (1980b) The need for germplasm conservation in wild cassava Indian J Genet Plant Breeding 39(3), 465 – 470 Nassar, N M A (1982) Collecting wild cassava in Brazil Indian J Genet Plant Breeding 42, 405–411 Nassar, N M A (1984) Natural hybrids between Manihot reptans Pax and M alutaced Rogers & Appan Can J Plant Sci 64, 423 – 425 Nassar, N M A (1985) Manihot neusana Nassar: A new species native to Parana, Brazil Can J Plant Sci 65, 1097–1100 Nassar, N M A (1986) Genetic variation of wild Manihot species native to Brazil and its potential for cassava improvement Field Crop Res 13, 177–184 Nassar, N M A (1989) Broadening the genetic base of cassava, Manihot esculenta Crantz, by interspecific hybridization Can J Plant Sci 69, 1071–1073 Nassar, N M A (1991) Production of triploid cassava, Manihot esculenta Crantz, by hybrid diploid gametes Field Crop Res 13, 173 –182 Nassar, N M A (1992) Cassava in South America: A plant breeder view Ciëncia Cultura (J Brazilian Assoc Advancement Sci.) 44, 25 –27 Nassar, N M A (1994a) Selection and development of apomitic cassava clone Ciëncia Cultura (J Brazilian Assoc Advancement Sci 41(6), 168 –171 Nassar, N M A (1994b) Relationship between Manihot species: A review of the proceedings of the 2nd Internacional Scientific Meeting of the Cassava Biotechnology Network Bogor, 90 –100 Nassar, N M A (1995) Development of cassava interspecific hybrids for savanna (cerrado) conditions J Root Crops 22, –17 Nassar, N M A., and Costa, C P (1978) Tuber formation and protein content in some wild cassava (mandioca) species native to central Brazil Experiëncia 33, 1304 –1306 Nassar, N M A., and Dorea, G (1982) Protein contents of cassava cultivars and its hybrid with Manihot species Turrialba 32(4), 429 – 432 Nassar, N M A., and Grattapaglia, D (1986) Variabilidade de clones de mandioca em relaỗóo ä fertilidade e aspectos morfológicos Turrialba 36(4), 555 – 559 Nassar, N M A., and O’Hair, S K (1985) Variation among clones in relation to seed germination Indian J Genet 45(2), 429 – 432 Nassar, N M A., Silva, J R., and Vieira, C (1986) Hibridaỗóo insterespecica entre mandioca e espécies silvestres Manihot Ciëncia Cultura ( J Brazilian Assoc Advancement Sci.) 33(6), 1050–1055 Nassar, N M A., Nassar, H N M., Vieira, C., and Saraiva, S L (1995) Cytogenetic behavior of interspecific hybrids of cassava and M neusansa Nassar Can J Plant Sci 75, 675 – 678 Nassar, N M A., Nassar, H N M., Carvalho, C G., and Vieira, C (1996a) Induction of a productive aneuploid in cassava, Manihot esculenta Crantz Brazilian J Genet 19, 123 –125 Nassar, N M A., Carvalho, C G., and Vieira, C (1996b) Overcoming barriers between cassava Manihot esculenta Crantz and wild relative M pohili Warwa Brazilian J Genet 19, 617– 620 Nassar, N M A., Vieira, M A., Vieira, C., and Grattapaglia, D (1998a) Molecular and embionic evidence of apomix in cassava interspecific hybrids (Manihot spp) Can J Plant Sci 78, 348 – 352 Nassar, N M A., Vieira, M A., Vieira, C., and Grattapaglia, D (1998b) Molecular and embryonic evidence of apomix in cassava (Manihot esculenta Crantz) Euphytica 102, –13 230 NAGIB M A NASSAR Nichols, R F W (1947) Breeding cassava for resistance East Afr Agr J 12(3), 184 –194 Novy, R G., Kobak, C., Gofreda, J., and Vorsa, N (1994) RAPDs identify varietal misclassification and regional divergence in cranberry (Vaccinium macrocarpon (Ait.) Pursh theor Appl Genet 88, 1004–2020 Oke, O L (1973) The mode of cyanide detoxification In “Chronic Cassava Toxicity Proceeding of Inderdisciplinary Workshop, London, 29– 30 January 1973” (B Nestel and R MacIntyte, Eds), pp 97–104 IDRC-OLOe, Ottawa, Ontario, Canada Parrot, W A., and Smith, R R (1984) Production of 2n pollen in red clover Crop Sci 24, 467– 472 Prakken, R., and Swaminathan, M S (1952) Cytological behaviour of some interspecific hybrids in the genus Solanum Genetic 54, 505 – 522 Raymond, W D., Jojo, W., and Zicodemus, Z (1941) The nutritive value of some Tanganyka foods: Cassava East Afr Agric J 6, 154 –159 Roads, M M., and Dempsey, E (1966) Induction of chromosome doubling at meiosis by elongated gene in maize Genetics 54, 505 – 522 Rogers, D J (1963) Studies on Manihot esculenta Crantz and related species Bull Torrey Bot Cl 99, 43–54 Rogers, D J., and Appan, C (1973) Manihot, Manihotoides, Euphorbiaceae In “Flora Neotropica.” Hafner, New York Rogers, D J., and Fleming, H S (1973) A monograph of Manihot esculenta with an explanation of the taximetrics method used Econ Bot 27, 1–113 Sastri, D C., and Shivanna, K R (1976) Attempts to overcome interspecific incompatibility in Sesanum by using recognition pollen Ann Bot 40, 891– 893 Schmidt, C B (1951) A mandioca, contribuiỗóo para o conhecimento de sua origem Boletim Agric 1, Stebbins, G L (1950) “Variation and Evolution in Plants.” Columbia Press, New York Vavilov, N I (1951) Phytogeographic basis of plant breeding The origin, variation, immunity and breeding of cultivated plants Chronica Bot 13, 1– 366 Vásquez, N., and Nassar, N M A (1994) Unreduced microspores in cassava, Manihot esculenta Crantz clones Indian J Genet Plant Breeding 54, 436 – 441 Vorsa, N., and Bingham, E T (1979) Cytology of pollen formation in diploid alfalfa, Medicago sativa Can J Genet Cytol 21, 526 – 530 Webber, K., and Osborn, M J (1969) The reliability of molecular weight determination by sulfate– polyacrilamide gel electrophoresis J Biol Chem 244, 4406 – 4412 Williams, J G K., Kubelik, A R., Livak, K J., Rafalski, J A., and Tingey, S V (1990) DNA polymorphisms amplified by arbitrary primers are useful as genetic markers Nucleic Acids Res 18, 6531–6535 Young, B A., Sherwood, R T., and Bashaw, E C (1979) Cleared-pistil and thick-sectioning techniques for detecting aposporous apomixis in grasses Can J Bot 57, 1668 –1672 Index A Absorption defined, 3–4 of phosphate in soil, 101 Acidolysis, 130 Adsorption defined, on mineral surfaces, of phosphate in soil, 101, 102 pH and, 104–105 Advection-dispersion equation, 50 Agricultural chemicals, see Herbicides; Pesticides Agricultural management adverse environmental effects, 76, 77 effects on soil organic matter, 87– 88 Agroecosystem Resources Group, 77 Agroecosystems environmental degradation and, 76 environmental indicators biological, 79–82 chemical, 83–84 of greatest significance, 78 –79 landscape, 83, 84–85 physical, 78, 82–83 ranking of, 90, 91t recommendations for using, 92 soil organic matter, 85 – 90 environmental monitoring and, 77–78 overview of, 76–77 Aluminum chelated by organic acids, 129 –130 in soil phosphorus dynamics, 102, 103 Aluminum phosphate solubility in liquid media, 125 Ammonium effects on phosphate solubilization by fungi, 132 Aneuploidy in cassava, 220–222 Apomixis in cassava, 210–215 Apospory in cassava, 214 –215 Aquifer remediation modeling, 65 Arrhenius equation, 32 Aruak Indians, 185 Aspergillus, see Fungi, phosphate-solubilizing B Bacteria phosphate solubilizing, 141–142 Base flow described, 160t, 172 phosphorus transfer and, 157–158 Batch solution-solid techniques, 45 – 49 Bioavailability coupled sorption-degradation kinetic models, 58 – 65 overview of, 56 – 58 of soil chemicals, 83 Biodegradation sorption-degradation kinetic models, 58 – 65 Biporous diffusion model, 36 – 37 “Black carbon” sorption by, 13 Bolivia wild species of Manihot in, 184 Brazil domestication of cassava in, 185 wild species of Manihot in, 181t, 182–184 Bridge species, 208, 209 –210 Bypass flow, 160t, 165 C Calcium in soil phosphorus dynamics, 102, 103 Calcium phosphate solubility in liquid media, 125 Carbon, atmospheric soil organic matter and, 86– 87 Carboxylic acids chelation of phosphate metal cations, 129 231 232 INDEX Cassava, see also Manihot apomixis in as apospory, 214 –215 embryo sac analysis of, 212–213, 214 –215 genetic study of, 210 –212 molecular analysis of, 213 –215 genetic origins of, 184 –185, 221–222 interspecific hybrids, 184 –185, 187 aneuploidy in, 221–222 apomixis and, 211–212 drought tolerance and, 204 –207 with M anomala, 198 –200 with M neusana, 198 –204 overcoming crossing barriers to M pohlii, 207–210 polyploidy and, 217–220 protein content, 225 –226 unreduced microspores in, 217–220, 223 – 224 place of domestication, 185 polyploidy in, 218 advantages of, 215 aneuploids, 220–222 through interspecific hybridization, 201– 202, 217–220 triploids, 222–224 unreduced microspores and, 215 –220, 223–224 protein content, 194, 196, 225, 226t relationship to Manihot species, 190 sectorial chimera in, 216 Catchment/watershed hydrological pathways, 163, 164, 166, 168 –172 Charge-transfer interactions, Chelation by organic acids, 127–130 Chemisorption, Chimeras in cassava, 216 Citric acid excreted by phosphate-solubilizing fungi, 126 Clays hindered diffusion and, 20 Coal sorption by, 13 Condensation defined, Continuous-flow stirred tank reactor, 54 – 56 Coordination complexes chemisorption and, Crop diversity as environmental indicator, 81– 82 Crop yield as environmental indicator, 78 soil organic matter and, 86 D Darcian flow, 160t, 165 Darken equation, 31– 32 Delphi technique, 90 Denbigh soil hydrological characteristics, 155, 156t Desorption, see also Sorption defined, nonequilibrium mechanisms in, 17–27 uptake and release profiles, 16 –17 rate of, 14 zero-length columns, 56 Diffusion defined, 17–18 intraorganic matter diffusion, 20–23 soil pore diffusion, 18 –20 Diffusion equations, 31– 32 Diffusion models combined organic matter/pore diffusion model, 39 – 41 coupled with biodegradation kinetics, 62– 63 for fixed-pore systems, 32– 37 general considerations in, 30 – 32 for multiple particle sizes, 41– 43 for organic matter, 37– 39 for soil columns, 52– 54 Drought tolerance cassava interspecific hybrids and, 204–207 Dual resistance diffusion model, 36 – 37 E Earthworms as environmental indicators, 80 Electrodynamic thermogravimetric analyzer, 49 Environmental indicators agricultural chemical use, 79 biological, 79 crop diversity, 81– 82 crop productivity, 78 earthworms, 80 fecal pathogens, 82 233 INDEX genetic diversity, 79 honeybees, 80–81 insects, 78, 81 pesticide resistance, 81 soil microbial status, 80 landscape, 83, 84–85 physical, 78, 82–83 ranking of, 90, 91t recommendations for using, 92 soil chemicals, 83–84 soil organic matter, 85 – 90 Environmental monitoring assessment endpoints, 77–78 federal agencies in, 77 pressure-state-response framework, 78 Environmental Protection Agency ranking of landscape metrics, 85 Equilibrium partition bioavailability model, 58 Erosion effects on soil organic matter, 87– 88 F Fava-Eyring model, 30 Fecal pathogens as environmental indicators, 82 Ficks’s laws, 31–32 Field capacity, 157 Film resistance sorption model, 30 First-order solute transport model with biodegradation term, 61 with sorption kinetic term, 52 Freundlich equation, 34 Fulvic acids, Fungi vesicular mycorrhizal, 100, 141–142 Fungi, phosphate-solubilizing, 100, 144 agar studies, 107 liquid medium studies chelation of cations by organic acids, 127– 130 nitrogen source effects, 132 pH effects, 109, 124, 130–131 production of organic acids, 126 –127 results from, 110–123t solubility of phosphate compounds, 109, 124–126 time-related soluble phosphate fluctuations, 132–133 titratable acidity and, 130 promotion of plant growth by, 133, 134 –140t, 141–143 G Genetic diversity as environmental indicator, 79 Gluconate excreted by phosphate-solubilizing fungi, 126 –127 Graciles, 186 Groundwater phosphorus transfer and, 172 H Hallsworth soil hydrological characteristics, 155, 156t Herbicides environmental health and, 79 Honeybees as environmental indicators, 80 – 81 HOST classification, see Hydrology of soil types classification Humic acids, Humic substances, Humin, Hydrocyanic acid in Manihot tubers, 194, 195 Hydrogen bonding in organic molecules, Hydrological pathways phosphorus transfer and overview of, 154 –155 scale effects, 162–164 at the slope/field scale, 166, 168 –172 at the soil profile scale, 165 –166 temporal aspects of, 158, 159f terminology and, 164 timescales in, 158 –161 types of, 160 –161t variable source areas, 171 Hydrology of soil types (HOST) classification, 155, 166, 167f Hydrophobic effect, 13 –14 Hydroxylated mineral surfaces, Hysteresis isotherm, 24 –26 kinetic, 26 –27 overview of, 24 234 INDEX I Infiltration-excess overland flow, 170 –171 Insects as environmental indicators, 78 Intraorganic matter diffusion overview of, 20–22 structure activity relationships in, 22–23 Ion-exchange forces, Iron in soil phosphorus dynamics, 102, 103 Isotherm hysteresis, 24 –26 K Kerogen sorption by, 13 ␤-Ketogluconic acid, 130 Kinetic hysteresis, 26–27 L Land drainage phosphorus transfer and, 172 Landscape in environmental assessments, 83, 84 – 85 National Resource Inventory and, 83 Langmuir kinetic model, 27–28 Leaching described, 160t use of term, 164 Linear driving force sorption models, 29 – 30 with biodegradation term, 61– 62 M Macropore flow, 160t, 165 Macropores modeling diffusion in, 33 – 35 size of, 18 Manihot, see also Cassava adaptation to climatic conditions, 197–198 centers of diversity, 184, 185 –186 chromosome number, 186, 187t genetic variability, 190, 193 –198 growth habit, 193t, 196 hybridization with cassava, 184 –185, 187 aneuploidy in, 221–222 apomixis and, 211–212 characterization of hybrids, 200 –204 drought tolerance and, 204 –207 overcoming crossing barriers, 207–210 polyploidy and, 217–220 production of hybrids, 198 –200 protein content, 225 –226 unreduced microspores in, 217–220, 223 – 224 interspecific hybridization in, 186 –187, 196 natural habitats, 193t, 196 relationships between species, 186 –190, 191t, 192t species in Brazil, 181t, 182–184 taxonomy of, 180 –181 tuber formation patterns, 193 –194 tuber hydrocyanic acid content, 194, 195 tuber protein content, 194 –195, 196, 225 – 226, 227t M anomala, 198 –200 M brachyandra, 225, 226 M caerulescens, 197–198 M dichotoma, 211 M falcata, 196 M glaziovii, 181, 200, 204, 218, 220 M oligantha, 225 M oligantha subsp nestili, 194, 195 M paviaefolia, 196 M pohlii, 207–210 M procumbens, 198 M pruinosa, 196 M pseudoglaziovii, 201, 204, 220, 221, 222– 223 M reptans, 186 –187, 196 M saxicola, 195 M stipularis, 198 Manihot esculenta, see Cassava Manihot neusana as bridge species in hybridization, 208, 209 – 210 hybridization with cassava, 198 –200, 220 cytogenetic behavior of backcrossed generation, 202–203 cytogenetic behavior of parents, 203 evolutionary and breeding significance of, 203 –204 meiotic behavior of F1 hybrids, 200–202 Manihotoides pouciflora, 186 Meiotic restitution in cassava interspecific hybrids, 201, 202 Mentor pollen, 208 Mercuric chloride, 47 INDEX Mesopores modeling diffusion in, 33 – 35 size of, 18 Meteorological field capacity, 157 Mexico wild species of Manihot in, 183 Micropores modeling diffusion in, 35 size of, 18 Microspores, unreduced in cassava, 216–217 interspecific hybrids, 217–220, 223 –224 overview of, 215–216 Mineral surfaces sorption and, 6–7 types of, N National Resource Inventory, 83 Nitrate effects on phosphate solubilization by fungi, 132 Nitrogen effects on phosphate solubilization by fungi, 132 Nonaqueous phase liquids sorption by, 13 Nonlinear driving force sorption models, 29 – 30 O Organic acids excreted by phosphate-solubilizing fungi, 126–127 chelation of phosphate metal cations by, 127–130 excreted by roots, 106 stability constants for, 128t Organoclays sorption in, 20 Overland flow described, 160t, 164 phosphorus transfer and, 170 –171 Oxalic acid excreted by phosphate-solubilizing fungi, 126 P Partial-area runoff, 170 Penicillium, see Fungi, phosphate-solubilizing 235 Pesticide resistance as environmental indicator, 81 Pesticides environmental health and, 79 pH, see also Soil pH effects on phosphate solubility in liquid media, 109, 124, 130 –131 Phenathrene, 17 Phosphate, see also Fungi, phosphate-solubilizing; Phosphorus transfer; Soil phosphorus in liquid medium studies chelation of metal ions by organic acids, 127–130 pH effects and, 109, 124, 130–131 solubility of, factors affecting, 109, 124 – 126 time-based fluctuations in, 132–133 titratable acidity and, 130 precipitation in soils, 102–103 sorption in soils, 101–102 Phosphate fertilizers soil accumulation of phosphate, 100, 103, 154 Phosphorus transfer effective rainfall and, 155, 157, 158 hydrological pathways scale effects, 162–164 at the slope/field scale, 166, 168 –172 at the soil profile scale, 165 –166 temporal aspects of, 158, 159f levels of hydrological activity and, 157–158 overview of, 154 –155, 173 Physisorption on mineral surfaces, overview of, – rates of, 14 –15 Piston flow, 161t, 165 Plants uptake of soil phosphate, 105 –106 Pollen mentor, 208 Pollutant transfer, 154, see also Phosphorus transfer Polycyclic aromatic hydrocarbons sorption by soot, 13 Polyploidy, in cassava, 218 advantages of, 215 aneuploids, 220 –222 through interspecific hybridization, 201–202, 217–220 triploids, 222–224 236 INDEX Polyploidy (continued) unreduced microspores and, 215 –220, 223 – 224 Precipitation phosphorus transfer and, 155, 157, 158 Preferential flow, 161t, 165 –166 Pressure-state-response framework, 78 Probability density functions, 43 – 44 Propylene oxide, 47 R Radial diffusion laws coupled with biodegradation kinetics, 62– 63 Rainfall phosphorus transfer and, 155, 157, 158 Return flow, 161t, 171 Rhizosphere solubilization of phosphates in, 105 –106 Roots of drought tolerant cassava hybrids, 205 –207 Runoff described, 161t phosphorus transfer and, 169 –170 use of term, 164 S Saturated flow, 161t, 165 Saturation-excess overland flow, 171 Self-diffusion, 31–32 Shale sorption by, 13 Siloxane mineral surfaces, Slope/field hydrological pathways, 162, 164, 166, 168–172 Sodium azide, 47 Soil accumulation of phosphate in, 100, 103, 154 bioavailability of chemicals in, 56 – 58 soil organic matter in factors controlling content of, 87– 88 functions of, 86 sorption in heterogeneous soils, 23 –24 mineral surfaces, –7 other carbonaceous material, 13 soil organic matter, –12 types of hydrological pathways through, 158 – 161 typing by hydrological characteristics, 155, 156t Soil aggregates, 33 Soil chemicals bioavailability of, 83 as environmental indicators, 83 – 84 Soil columns advection-dispersion equation, 50 overview of, 49 – 51 transport models with sorption kinetic terms, 51– 54 zero-length, 56 Soil degradation as environmental indicator, 82 Soil microorganisms as environmental indicators, 80 phosphate solubilizing, 106 –108 (see also Fungi, phosphate–solubilizing) soil phosphorus dynamics and, 100 Soil nutrients as environmental indicators, 83 – 84 Soil organic matter atmospheric carbon and, 86 – 87 components of, defined, 85 – 86 diffusion models for, 37– 41 as environmental indicator, 85 – 90 functions of, 86 hindered diffusion in, 20 –22, 23 hysteresis and, 25 –26 measures of, 88 models of sorption in, –12 quantities of, measuring and expressing, 89 – 90 rubber-glassy polymer concept of, –12 in soil aggregates, 33 soil content of, factors controlling, 87– 88 sorption rates, 15 Soil particles description of, 32– 33 diffusion models and for multiple particle sizes, 41– 43 for particles with fixed pore sizes, 32– 37 Soil pH phosphate solubility and, 104 –105 Soil phosphorus, see also Fungi, phosphate-solubilizing cycle, 103 –104 deficiency in, 104 overview of, 100 237 INDEX phosphate sorption, 101–102 plant uptake of, 105–106 precipitation of phosphate compounds, 102–103 soil pH and, 104–105 Soil pores condensation and, diffusion models for biporous particles, 36 – 37 combined pore diffusion/organic matter model, 39–41 for macropores, 33– 35 for mesopores, 33– 35 for micropores, 35 diffusion through, 18–20 size classes, 18 water concentration and bioavailability relationship, 58 Soil productivity as environmental indicator, 78 Soil profile hydrological pathways, 165 –166 Soil solution phosphorus dynamics and, 103 –104 Solute transport models advection-dispersion equation, 50 with biodegradation term, 63 – 65 with sorption kinetic term diffusion model, 52– 54 first-order model, 52 two-region model, 51– 52 Soot sorption by, 13 Sorbate, Sorbent, Sorption, see also Sorption, nonequilibrium; Sorption kinetics categories of, 3–5 defined, experimental methods batch techniques, 45 – 49 column techniques, 49 – 54 stirred-flow cell techniques, 54 – 56 time frames, 45 zero-length columns, 56 factors affecting, on mineral surfaces, –7 of phosphate in soil, 101–102 pH and, 104–105 steps in, thermodynamics of, 13 –14 types of molecular interactions in, – Sorption, nonequilibrium retardation mechanisms hysteresis, 24 –27 intraorganic matter diffusion, 20–23 overview of, 17–18 pore diffusion, 18–20 soil heterogeneity and, 23 –24 uptake and release profiles, 16 –17 Sorption kinetics bioavailability of soil chemicals and, 56 – 58 models based on bond energetics, 27–29 coupled sorption-degradation models, 58 – 65 diffusion models, 30 – 43, 62– 63 linear driving force models, 29 – 30, 61– 62 solute transport models, 50 – 54, 63 – 65 stochastic models, 43 – 45 rates of elementary processes in, 14 –15 significance of, Static batch reactor, 49 Stirred-flow cells, 54 – 56 Stochastic sorption models, 43 – 45 Storm flow phosphorus transfer and, 157, 158 Storm runoff, 171 Subsurface flow, 161t, 164 Successive-dilution technique, 48 Surface runoff described, 161t phosphorus transfer and, 170 –171 T Throughflow described, 161t phosphorus transfer and, 171–172 Tillage effects on soil organic matter, 87, 88 Titratable acidity, 130 Tortuosity in diffusion through pores, 18 Transgenic crops pest resistance and, 81 Transport diffusion, 31– 32 Tripartitae, 186 Triploidy in cassava, 222–224 238 INDEX W Tupi-Guarani Indians, 185 Two-region solute transport model, 51– 52 V Van Der Waals forces in physisorption, Vesicular mycorrhizal fungi, 100, 141–142 Water films sorption and, Z Zero-length columns, 56 ... matter Retardation in the fixed pore system is due to tortuosity, chromatographic adsorption to pore walls, and, in the smallest pores, steric hindrance Advances in Agronomy, Volume 69 Copyright ©... interactions occur with the walls, giving rise to nonlinearity and competitive sorption The binding is analogous to host–guest inclusion complexes in chemistry (Reprinted from Xing and Pignatello, 1997.)... by breaking up particles (Steinberg et al., 1987; Ball and Roberts, 1991b) Resistant fractions may be formed in soils containing no appreciable mineral matter (e.g., Fig 6), in strictly inorganic