Roots of the Second Green Revolution

The Green Revolution boosted crop yields in developing nations by introducing dwarf genotypes of wheat and rice capable of responding to fertilisation without lodging. We now need a second Green Revolution, to improve the yield of crops grown in infertile soils by farmers with little access to fertiliser, who represent the majority of third-world farmers. Just as the Green Revolution was based on crops responsive to high soil fertility, the second Green Revolution will be based on crops tolerant of low soil fertility. Substantial genetic variation in the productivity of crops in infertile soil has been known for over a century. In recent years we have developed a better understanding of the traits responsible for this variation. Root architecture is critically important by determining soil exploration and therefore nutrient acquisition. Architectural traits under genetic control include basal-root gravitropism, adventitious-root formation and lateral branching. Architectural traits that enhance topsoil foraging are important for acquisition of phosphorus from infertile soils. Genetic variation in the length and density of root hairs is important for the acquisition of immobile nutrients such as phosphorus and potassium. Genetic variation in root cortical aerenchyma formation and secondary development (‘root etiolation’) are important in reducing the metabolic costs of root growth and soil exploration. Genetic variation in rhizosphere modification through the efflux of protons, organic acids and enzymes is important for the mobilisation of nutrients such as phosphorus and transition metals, and the avoidance of aluminum toxicity. Manipulation of ion transporters may be useful for improving the acquisition of nitrate and for enhancing salt tolerance. With the noteworthy exceptions of rhizosphere modification and ion transporters, most of these traits are under complex genetic control. Genetic variation in these traits is associated with substantial yield gains in low-fertility soils, as illustrated by the case of phosphorus efficiency in bean and soybean. In breeding crops for low-fertility soils, selection for specific root traits through direct phenotypic evaluation or molecular markers is likely to be more productive than conventional field screening. Crop genotypes with greater yield in infertile soils will substantially improve the productivity and sustainability of low-input agroecosystems, and in high-input agroecosystems will reduce the environmental impacts of intensive fertilisation. Although the development of crops with reduced fertiliser requirements has been successful in the few cases it has been attempted, the global scientific effort devoted to this enterprise is small, especially considering the magnitude of the humanitarian, environmental and economic benefits being forgone. Population growth, ongoing soil degradation and increasing costs of chemical fertiliser will make the second Green Revolution a priority for plant biology in the 21st century.

[1]  M. Farquhar,et al.  Root hairs: Specialized tubular cells extending root surfaces , 2008, The Botanical Review.

[2]  Alexander Lux,et al.  Zinc in plants. , 2007, The New phytologist.

[3]  D. T. Britto,et al.  Futile cycling at the plasma membrane: a hallmark of low-affinity nutrient transport. , 2006, Trends in plant science.

[4]  M. Carvajal,et al.  Plant Aquaporins: New Perspectives on Water and Nutrient Uptake in Saline Environment , 2006, Plant biology.

[5]  Qifa Zhang,et al.  Plant nutriomics in China: an overview. , 2006, Annals of botany.

[6]  M. Blair,et al.  QTL Analysis of Adventitious Root Formation in Common Bean under Contrasting Phosphorus Availability , 2006 .

[7]  Shawn M. Kaeppler,et al.  Detection of quantitative trait loci for seminal root traits in maize (Zea mays L.) seedlings grown under differential phosphorus levels , 2006, Theoretical and Applied Genetics.

[8]  J. Lynch,et al.  Whole-Plant Adaptations to Low Phosphorus Availability , 2006 .

[9]  S. A. Barber,et al.  A numerical solution of whole plant nutrient uptake for soil-root systems with root hairs , 1983, Plant and Soil.

[10]  Peter J. Gregory,et al.  Rhizosphere geometry and heterogeneity arising from root-mediated physical and chemical processes. , 2005, The New phytologist.

[11]  J. Lynch,et al.  Topsoil foraging and phosphorus acquisition efficiency in maize (Zea mays). , 2005, Functional plant biology : FPB.

[12]  J. Lynch,et al.  Root architectural tradeoffs for water and phosphorus acquisition. , 2005, Functional plant biology : FPB.

[13]  J. Lynch,et al.  Mapping of QTLs for lateral root branching and length in maize (Zea mays L.) under differential phosphorus supply , 2005, Theoretical and Applied Genetics.

[14]  J. A. Tolk,et al.  Seeding Practices and Cultivar Maturity Effects on Simulated Dryland Grain Sorghum Yield , 2005 .

[15]  Pedro A Sanchez,et al.  Hunger in Africa: the link between unhealthy people and unhealthy soils , 2005, The Lancet.

[16]  L. Kochian,et al.  Aluminum Resistance in Maize Cannot Be Solely Explained by Root Organic Acid Exudation. A Comparative Physiological Study1[w] , 2005, Plant Physiology.

[17]  D. G. Lewis,et al.  Phosphate diffusion in soil and uptake by plants , 1967, Plant and Soil.

[18]  D. G. Lewis,et al.  Phosphate diffusion in soil and uptake by plants , 1967, Plant and Soil.

[19]  B. Kindiger,et al.  Identification of QTL controlling adventitious root formation during flooding conditions in teosinte (Zea mays ssp. huehuetenangensis) seedlings , 2005, Euphytica.

[20]  A. Dobermann,et al.  Plant Nutrition for Food Security, Human Health and Environmental Protection , 2005 .

[21]  D. Robinson Integrated Root Responses to Variations in Nutrient Supply , 2005 .

[22]  H. Bassirirad Nutrient acquisition by plants : an ecological perspective , 2005 .

[23]  J. Lynch Root Architecture and Nutrient Acquisition , 2005 .

[24]  R. Simpson,et al.  Expression of a fungal phytase gene in Nicotiana tabacum improves phosphorus nutrition of plants grown in amended soils. , 2005, Plant Biotechnology Journal.

[25]  Jonathan P. Lynch,et al.  Architectural Tradeoffs between Adventitious and Basal Roots for Phosphorus Acquisition , 2005, Plant and Soil.

[26]  J. Lynch,et al.  Mapping of QTL controlling root hair length in maize (Zea mays L.) under phosphorus deficiency , 2005, Plant and Soil.

[27]  J. Lynch,et al.  Rhizoeconomics: Carbon costs of phosphorus acquisition , 2005, Plant and Soil.

[28]  S. S. Clair,et al.  Mineral stress: the missing link in understanding how global climate change will affect plants in real world soils , 2004 .

[29]  J. Lynch,et al.  The contribution of lateral rooting to phosphorus acquisition efficiency in maize (Zea mays) seedlings. , 2004, Functional plant biology : FPB.

[30]  Xiaolong Yan,et al.  Genetic mapping of basal root gravitropism and phosphorus acquisition efficiency in common bean. , 2004, Functional plant biology : FPB.

[31]  Melissa D. Ho Effects of root architecture, plasticity, and tradeoffs on water and phosphorus acquisition in heterogeneous environments. , 2004 .

[32]  M. Blair,et al.  QTL mapping of root hair and acid exudation traits and their relationship to phosphorus uptake in common bean , 2004, Plant and Soil.

[33]  F. Zhang,et al.  Acid phosphatase role in chickpea/maize intercropping. , 2004, Annals of botany.

[34]  D. T. Britto,et al.  Bioengineering nitrogen acquisition in rice: can novel initiatives in rice genomics and physiology contribute to global food security? , 2004, BioEssays : news and reviews in molecular, cellular and developmental biology.

[35]  S. C. Tripathi,et al.  Lodging behavior and yield potential of spring wheat (Triticum aestivum L.): effects of ethephon and genotypes , 2004 .

[36]  J. Lynch,et al.  Phosphatase Under-Producer Mutants Have Altered Phosphorus Relations1 , 2004, Plant Physiology.

[37]  N. E. Nielsen,et al.  Root traits as tools for creating phosphorus efficient crop varieties , 2004, Plant and Soil.

[38]  Jonathan P Lynch,et al.  Optimization modeling of plant root architecture for water and phosphorus acquisition. , 2004, Journal of theoretical biology.

[39]  D. Schachtman,et al.  Over-Expression of an Arabidopsis Zinc Transporter in Hordeum Vulgare Increases Short-Term Zinc Uptake after Zinc Deprivation and Seed Zinc Content , 2004, Plant Molecular Biology.

[40]  Ross M. Welch,et al.  Breeding for micronutrients in staple food crops from a human nutrition perspective. , 2004, Journal of experimental botany.

[41]  T. Setter,et al.  Review of prospects for germplasm improvement for waterlogging tolerance in wheat, barley and oats , 2003, Plant and Soil.

[42]  A. Condon,et al.  Avenues for increasing salt tolerance of crops, and the role of physiologically based selection traits , 2002, Plant and Soil.

[43]  C. Johansen,et al.  Scope for genetic manipulation of mineral acquisition in chickpea , 2002, Plant and Soil.

[44]  Z. Rengel Genetic control of root exudation , 2002, Plant and Soil.

[45]  N. Ae,et al.  Root cell-wall properties are proposed to contribute to phosphorus (P) mobilization by groundnut and pigeonpea , 2002, Plant and Soil.

[46]  J. Lynch,et al.  Topsoil foraging – an architectural adaptation of plants to low phosphorus availability , 2001, Plant and Soil.

[47]  J. Lynch,et al.  Morphological synergism in root hair length, density, initiation and geometry for phosphorus acquisition in Arabidopsis thaliana: A modeling approach , 2001, Plant and Soil.

[48]  S. Kaeppler,et al.  Induction of maize acid phosphatase activities under phosphorus starvation , 2001, Plant and Soil.

[49]  J. Lynch,et al.  Root hairs confer a competitive advantage under low phosphorus availability , 2001, Plant and Soil.

[50]  N. E. Nielsen,et al.  A root hairless barley mutant for elucidating genetic of root hairs and phosphorus uptake , 2001, Plant and Soil.

[51]  P. Hinsinger Bioavailability of soil inorganic P in the rhizosphere as affected by root-induced chemical changes: a review , 2001, Plant and Soil.

[52]  N. E. Nielsen,et al.  Phosphorus (P) acquisition of cereal cultivars in the field at three levels of P fertilization , 1999, Plant and Soil.

[53]  N. E. Nielsen,et al.  Variation in root hairs of barley cultivars doubled soil phosphorus uptake , 1997, Euphytica.

[54]  N. Galwey,et al.  A geographical approach to identify phosphorus-efficient genotypes among landraces and wild ancestors of common bean , 1997, Euphytica.

[55]  N. E. Nielsen,et al.  Root hairs and phosphorus acquisition of wheat and barley cultivars , 1997, Plant and Soil.

[56]  P. Ryser,et al.  Root and leaf attributes accounting for the performance of fast- and slow-growing grasses at different nutrient supply , 1995, Plant and Soil.

[57]  N. Claassen,et al.  Phosphorus efficiency of plants , 1991, Plant and Soil.

[58]  P. Nye,et al.  Diffusion of phosphate to plant roots in soil , 1976, Plant and Soil.

[59]  P. Nye,et al.  Diffusion of phosphate to plant roots in soil , 1973, Plant and Soil.

[60]  Xiaolong Yan,et al.  Effect of phosphorus availability on basal root shallowness in common bean , 2004, Plant and Soil.

[61]  A. Karthikeyan,et al.  Phosphate Acquisition , 2004, Plant and Soil.

[62]  L. Kochian,et al.  The Physiology, Genetics and Molecular Biology of Plant Aluminum Resistance and Toxicity , 2005, Plant and Soil.

[63]  H. Lambers,et al.  Chickpea and white lupin rhizosphere carboxylates vary with soil properties and enhance phosphorus uptake , 2004, Plant and Soil.

[64]  Fusuo Zhang,et al.  Chickpea facilitates phosphorus uptake by intercropped wheat from an organic phosphorus source , 2004, Plant and Soil.

[65]  D. Jones,et al.  Organic acid behavior in soils – misconceptions and knowledge gaps , 2004, Plant and Soil.

[66]  J. Graham,et al.  Is there a role for arbuscular mycorrhizal fungi in production agriculture? , 2004, Plant and Soil.

[67]  Jonathan P Lynch,et al.  The importance of root gravitropism for inter-root competition and phosphorus acquisition efficiency: results from a geometric simulation model , 2004, Plant and Soil.

[68]  H. Sentenac,et al.  Molecular mechanisms and regulation of K+ transport in higher plants. , 2003, Annual review of plant biology.

[69]  K. L. Nielsen,et al.  Genetic variation for adventitious rooting in response to low phosphorus availability: potential utility for phosphorus acquisition from stratified soils. , 2003, Functional plant biology : FPB.

[70]  N. E. Nielsen,et al.  Phosphorus (P) uptake and growth of a root hairless barley mutant (bald root barley, brb) and wild type in low- and high-P soils , 2003 .

[71]  M. Rosegrant,et al.  Ending Hunger in Our Lifetime: Food Security and Globalization , 2003 .

[72]  J. Lynch,et al.  Physiological roles for aerenchyma in phosphorus-stressed roots. , 2003, Functional plant biology : FPB.

[73]  V. Dunbabin,et al.  Is there an optimal root architecture for nitrate capture in leaching environments? , 2003, Plant, cell & environment.

[74]  J. Myers,et al.  Contributions of the Bean/Cowpea CRSP to cultivar and germplasm development in common bean , 2003 .

[75]  M. Hawkesford,et al.  Aerenchyma formation in roots of maize during sulphate starvation , 2003, Planta.

[76]  Dan Yu,et al.  The significance of lateral roots in phosphorus (P) acquisition of water hyacinth (Eichhornia crassipes) , 2003 .

[77]  J. Lynch,et al.  Topsoil Foraging and Its Role in Plant Competitiveness for Phosphorus in Common Bean , 2003, Crop Science.

[78]  C. Vance,et al.  Phosphorus acquisition and use: critical adaptations by plants for securing a nonrenewable resource. , 2003, The New phytologist.

[79]  J. Lynch,et al.  Growth, gas exchange, water relations, and ion composition of Phaseolus species grown under saline conditions , 2003 .

[80]  E. V. Oosterom,et al.  A yield architecture framework to explain adaptation of pearl millet to environmental stress , 2003 .

[81]  A. Hartemink Soil Fertility Decline in the Tropics: With Case Studies on Plantations , 2003 .

[82]  W. Wiseman,et al.  Gulf of Mexico Hypoxia, A.K.A. “The Dead Zone” , 2002 .

[83]  J. Lynch,et al.  Salinity Tolerance in Phaseolus Species during Early Vegetative Growth , 2002 .

[84]  O. Leyser,et al.  Root system architecture determines fitness in an Arabidopsis mutant in competition for immobile phosphate ions but not for nitrate ions , 2002, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[85]  J. Lynch,et al.  Salinity Tolerance of Phaseolus Species during Germination and Early Seedling Growth , 2002 .

[86]  S. Salvi,et al.  Mapping QTLs regulating morpho-physiological traits and yield: case studies, shortcomings and perspectives in drought-stressed maize. , 2002, Annals of botany.

[87]  M. Tollenaar,et al.  Yield potential, yield stability and stress tolerance in maize , 2002 .

[88]  C. Ticconi,et al.  Phosphate sensing in higher plants. , 2002, Physiologia plantarum.

[89]  H. Lambers,et al.  The respiratory patterns in roots in relation to their functioning , 2002 .

[90]  P. Sánchez,et al.  Soil Fertility and Hunger in Africa , 2002, Science.

[91]  Alastair H. Fitter,et al.  7 – An Ecological Perspective , 2002 .

[92]  G. Neumann,et al.  Root-induced changes in the availability of nutrients in the rhizosphere. , 2002 .

[93]  A. Eshel,et al.  Root-bacteria interactions: symbiotic N2 fixation. , 2002 .

[94]  P. Sánchez Ecology. Soil fertility and hunger in Africa. , 2002, Science.

[95]  J. Lynch,et al.  Root Gravitropism and Below-ground Competition among Neighbouring Plants: A Modelling Approach , 2001 .

[96]  C. Vance,et al.  Symbiotic nitrogen fixation and phosphorus acquisition. Plant nutrition in a world of declining renewable resources. , 2001, Plant physiology.

[97]  E. Delhaize,et al.  FUNCTION AND MECHANISM OF ORGANIC ANION EXUDATION FROM PLANT ROOTS. , 2001, Annual review of plant physiology and plant molecular biology.

[98]  M. Palmgren PLANT PLASMA MEMBRANE H+-ATPases: Powerhouses for Nutrient Uptake. , 2001, Annual review of plant physiology and plant molecular biology.

[99]  Z. Rengel GENOTYPIC DIFFERENCES IN MICRONUTRIENT USE EFFICIENCY IN CROPS , 2001 .

[100]  J. Lynch,et al.  Regulation of root hair density by phosphorus availability in Arabidopsis thaliana , 2001 .

[101]  A. Jungk Root hairs and the acquisition of plant nutrients from soil , 2001 .

[102]  F. Nachtergaele Soil taxonomy—a basic system of soil classification for making and interpreting soil surveys: Second edition, by Soil Survey Staff, 1999, USDA–NRCS, Agriculture Handbook number 436, Hardbound , 2001 .

[103]  K. L. Nielsen,et al.  The effect of phosphorus availability on the carbon economy of contrasting common bean (Phaseolus vulgaris L.) genotypes. , 2001, Journal of experimental botany.

[104]  C. Vance,et al.  Overexpression of malate dehydrogenase in transgenic alfalfa enhances organic acid synthesis and confers tolerance to aluminum. , 2001, Plant physiology.

[105]  L. Herrera-Estrella,et al.  Organic acid metabolism in plants: from adaptive physiology to transgenic varieties for cultivation in extreme soils. , 2000, Plant science : an international journal of experimental plant biology.

[106]  D. Shibata,et al.  Overexpression of mitochondrial citrate synthase in Arabidopsis thaliana improved growth on a phosphorus-limited soil. , 2000, Plant & cell physiology.

[107]  R. Koide Functional complementarity in the arbuscular mycorrhizal symbiosis. , 2000 .

[108]  Robert Wilkinson,et al.  Plant-environment interactions , 2000 .

[109]  J. Lynch,et al.  The efficiency of Arabidopsis thaliana (Brassicaceae) root hairs in phosphorus acquisition. , 2000, American journal of botany.

[110]  J. Lynch,et al.  Plant growth and phosphorus accumulation of wild type and two root hair mutants of Arabidopsis thaliana (Brassicaceae). , 2000, American journal of botany.

[111]  B. Forde,et al.  Nitrate transporters in plants: structure, function and regulation. , 2000, Biochimica et biophysica acta.

[112]  P J White,et al.  Calcium channels in higher plants. , 2000, Biochimica et biophysica acta.

[113]  E. Blumwald,et al.  Sodium transport in plant cells. , 2000, Biochimica et biophysica acta.

[114]  Luis Herrera-Estrella,et al.  Enhanced phosphorus uptake in transgenic tobacco plants that overproduce citrate , 2000, Nature Biotechnology.

[115]  S. Kaeppler,et al.  Variation among maize inbred lines and detection of quantitative trait loci for growth at low phosphorus and responsiveness to arbuscular mycorrhizal fungi , 2000 .

[116]  C. Vance,et al.  Biological Nitrogen Fixation: Phosphorus - A Critical Future Need? , 2000 .

[117]  H. Neue,et al.  Impact of phosphorus supply on root exudation, aerenchyma formation and methane emission of rice plants , 1999 .

[118]  S. S. Virmani,et al.  Yield Potential Trends of Tropical Rice since the Release of IR8 and the Challenge of Increasing Rice Yield Potential , 1999 .

[119]  G. Khush Green revolution: preparing for the 21st century. , 1999, Genome.

[120]  F. Martin Sustainability, Growth, and Poverty Alleviation. A policy and Agroecological Perspective , 1999 .

[121]  W. Armstrong,et al.  Formation of Aerenchyma and the Processes of Plant Ventilation in Relation to Soil Flooding and Submergence , 1999 .

[122]  A. Mollier,et al.  Maize root system growth and development as influenced by phosphorus deficiency , 1999 .

[123]  Kristian Borch,et al.  Ethylene: a regulator of root architectural responses to soil phosphorus availability , 1999 .

[124]  N. Crawford,et al.  Proteins for Transport of Water and Mineral Nutrients across the Membranes of Plant Cells , 1999, Plant Cell.

[125]  P H Abelson,et al.  A Potential Phosphate Crisis , 1999, Science.

[126]  H. Neue,et al.  Impact of phosphorus supply on root exudation, aerenchyma formation and methane emission of rice plants , 1999 .

[127]  T. Sinclair,et al.  Introgressing root aerenchyma into maize , 1999 .

[128]  Z. Rengel Physiological Mechanisms Underlying Differential Nutrient Efficiency of Crop Genotypes , 1999 .

[129]  J. Lynch The Role of Nutrient-Efficient Crops in Modern Agriculture , 1998 .

[130]  Steffen,et al.  Light and excess manganese . Implications for oxidative stress in common bean , 1998, Plant physiology.

[131]  矢野 勝也,et al.  シンポジウム「Phosphorus in Plant Biology : regulatory roles in molecular, cellular, organismic, and ecosystem processes」に参加して , 1998 .

[132]  K. L. Nielsen,et al.  Effects of phosphorus availability and vesicular–arbuscular mycorrhizas on the carbon budget of common bean (Phaseolus vulgaris) , 1998 .

[133]  I. Steen,et al.  Phosphorus availability in the 21st century : Management of a non-renewable resource , 1998 .

[134]  P. Shewry,et al.  Plant Roots - From Cells to Systems , 2012, Developments in Plant and Soil Sciences.

[135]  E. Newman Phosphorus balance of contrasting farming systems, past and present. Can food production be sustainable ? , 1997 .

[136]  M. Jackson,et al.  Plant adaptations to anaerobic stress , 1997 .

[137]  M. Stam,et al.  Review Article: The Silence of Genes in Transgenic Plants , 1997 .

[138]  J. Lynch,et al.  Utilization of phosphorus substrates by contrasting common bean genotypes , 1996 .

[139]  J. Lynch,et al.  Stimulation of root hair elongation in Arabidopsis thaliana by low phosphorus availability , 1996 .

[140]  M. Senior,et al.  Simple Sequence Repeat Markers Developed from Maize Sequences Found in the GENBANK Database: Map Construction , 1996 .

[141]  J. Lynch,et al.  Phosphorus responses of C3 and C4 species , 1996 .

[142]  J. Lynch,et al.  Effect of phosphorus deficiency on growth angle of basal roots in Phaseolus vulgaris. , 1996, The New phytologist.

[143]  J. Lynch,et al.  Phosphorus responses of C 3 and C 4 species , 1996 .

[144]  J. Lynch,et al.  Adaptation of beans (Phaseolus vulgaris L.) to low phosphorus availability , 1995 .

[145]  J. Lynch,et al.  Genetic Variation for Phosphorus Efficiency of Common Bean in Contrasting Soil Types: I. Vegetative Response , 1995 .

[146]  J. Ladha,et al.  Management of Biological Nitrogen Fixation for the Development of More Productive and Sustainable Agricultural Systems , 1995, Developments in Plant and Soil Sciences.

[147]  J. Lynch,et al.  Growth and architecture of seedling roots of common bean genotypes , 1993 .

[148]  J. Graham,et al.  Growth Depression in Mycorrhizal Citrus at High-Phosphorus Supply (Analysis of Carbon Costs) , 1993, Plant physiology.

[149]  J. Syvertsen,et al.  CARBON ECONOMY IN SOUR ORANGE IN RELATION TO MYCORRHIZAL COLONIZATION AND PHOSPHORUS STATUS , 1992 .

[150]  A. Goldstein Inducible Plant Proteins: Phosphate starvation inducible enzymes and proteins in higher plants , 1992 .

[151]  J. Lynch,et al.  Vegetative Growth of the Common Bean in Response to Phosphorus Nutrition , 1991 .

[152]  V. Shiva The Green Revolution in the Punjab , 1991 .

[153]  N. Claassen,et al.  II. Significance of root radius, root hairs and cation-anion balance for phosphorus influx in seven plant species , 1991 .

[154]  A. Eshel,et al.  Plant roots : the hidden half , 1991 .

[155]  I. Jakobsen,et al.  Carbon flow into soil and external hyphae from roots of mycorrhizal cucumber plants , 1990 .

[156]  M. Drew,et al.  Decreased Ethylene Biosynthesis, and Induction of Aerenchyma, by Nitrogen- or Phosphate-Starvation in Adventitious Roots of Zea mays L. , 1989, Plant physiology.

[157]  Shree P. Singh,et al.  SELECTION FOR YIELD AT TWO FERTILIZER LEVELS IN SMALL-SEEDED COMMON BEAN , 1989 .

[158]  C. R. Johnson,et al.  Carbon Cost of the Fungal Symbiont Relative to Net Leaf P Accumulation in a Split-Root VA Mycorrhizal Symbiosis. , 1988, Plant physiology.

[159]  H. Marschner Mineral Nutrition of Higher Plants , 1988 .

[160]  E. J. Kamprath,et al.  Soil Nutrient Bioavailability—A Mechanistic Approach , 1985 .

[161]  H. Mooney,et al.  Resource Limitation in Plants-An Economic Analogy , 1985 .

[162]  David T. Clarkson,et al.  Factors Affecting Mineral Nutrient Acquisition by Plants , 1985 .

[163]  J. Lynch,et al.  Influx and efflux of p in roots of intact maize plants : double-labeling with p and p. , 1984, Plant physiology.

[164]  J. Radin,et al.  Hydraulic conductance as a factor limiting leaf expansion of phosphorus-deficient cotton plants. , 1984, Plant physiology.

[165]  K. Koch,et al.  Photosynthate partitioning in split-root citrus seedlings with mycorrhizal and nonmycorrhizal root systems. , 1984, Plant physiology.

[166]  S. A. Barber,et al.  Phosphorus Uptake by Six Plant Species as Related to Root Hairs1 , 1983 .

[167]  J. Caradus Effect of root hair length on white clover growth over a range of soil phosphorus levels , 1981 .

[168]  R. G. Thomas The influence of environment on seed production capacity in white clover (Trifolium repens L.) , 1981 .

[169]  H. Konings,et al.  Formation of aerenchyma in roots of Zea mays in aerated solutions, and its relation to nutrient supply , 1980 .

[170]  A. Wild,et al.  AUTORADIOGRAPHY OF THE DEPLETION ZONE OF PHOSPHATE AROUND ONION ROOTS IN THE PRESENCE OF VESICULAR‐ARBUSCULAR MYCORRHIZA , 1979 .

[171]  R. Chaney,et al.  The Physiology of Metal Toxicity in Plants , 1978 .

[172]  P. Sánchez,et al.  Properties and Management of Soils in the Tropics , 1977 .

[173]  W. H. Gabelman,et al.  Intraspecific Differences in Growth of Beans at Stress Levels of Phosphorus1 , 1976, Journal of the American Society for Horticultural Science.

[174]  L. Saker,et al.  Nutrient Supply and the Growth of the Seminal Root System in Barley III. COMPENSATORY INCREASES IN GROWTH OF LATERAL ROOTS, AND IN RATES OF PHOSPHATE UPTAKE, IN RESPONSE TO A LOCALIZED SUPPLY OF PHOSPHATE , 1978 .

[175]  L. Saker,et al.  Nutrient Supply and the Growth of the Seminal Root System in Barley I. THE EFFECT OF NITRATE CONCENTRATION ON THE GROWTH OF AXES AND LATERALS , 1973 .

[176]  N. Borlaug The green revolution, peace and humanity : speech delivered upon receipt of the 1970 Nobel Peace Prize. Oslo, Norway. December 11, 1970 , 1972 .

[177]  C. Hackett A Method of Applying Nutrients Locally to Roots Under Controlled Conditions, and Some Morphological Effects of Locally Applied Nitrate on the Branching of Wheat Roots , 1972 .

[178]  Borlaug Ne The Green Revolution peace and humanity. , 1971 .

[179]  D. Bouldin Mathematical Description of Diffusion Processes in the Soil‐Plant System , 1961 .

[180]  K. Esau Anatomy of seed plants , 1960 .