2. S U E L O RECURSO NATURAL NO RENOVABLE, PARTE DEL “CICLO DE LA VIDA” EN LA TIERRA.

3. Basic Soil Plant Relationships Mineral Organic Water Air 45% ~5% 50% MATERIAL SÓLIDO (50%) POROUS MEDIA (50%)

7. F E R T I L I D A D CAPACIDAD DE PRODUCCIÓN DEL SUELO ( proporcionar a los vegetales los nutrientes para un desarrollo equilibrado) QUE PARA MANIFESTARSE NECESITA LA CONTRIBUCIÓN DE OTROS FACTORES: - físicos / - químicos / -biológicos - fisicoquímicos / - bioquímicos

10. SOSTENIBILIDAD CAPACIDAD O HABILIDAD DE SOSTENER PROCESOS EN FORMA CONTÍNUA, EVITANDO SU DECAIMIENTO AGRICULTURA SOSTENIBLE Cuando se manejan exitosamente los recursos para satisfacer las necesidades cambiantes de la sociedad, conservar los recursos naturales y en algunos casos, mantener y/o mejorar el medio ambiente

14. 1. Nutrición vegetal??? Tomar los elementos minerales desde el suelo No se refiere específicamente a la fotosíntesis.

16. Nombre % en planta relativo a N Funciones Macronutrientes (primarios) Nitrogen N 100 Proteins, amino acids Phosphorus P 6 Nucleic acids, ATP Potassium K 25 Catalyst, ion transport Mesonutrientes ( secundarios) Calcium Ca 12.5 Cell wall component Magnesium Mg 8 Part of chlorophyll Sulfur S 3 Amino acids Iron Fe 0.2 Chlorophyll synthesis Micronutrients (oligoelementos) Copper Cu 0.01 Component of enzymes Manganese Mn 0.1 Activates enzymes Zinc Zn 0.03 Activates enzymes Boron B 0.2 Cell wall component Molybdenum Mo 0.0001 Involved in N fixation Chlorine Cl 0.3 Photosynthesis reactions

17. 3. Absorción de los minerales desde el suelo Dominant in mineral soils: Dominant in organic soils: A. Bulk flow: Uptake in the transpiration stream B. Mycorrhizae: symbiotic relationship with fungi Nutrients diffuse to regions of low concentration and roots grow into and proliferate in soil zones with high nutrient concentrations (horse manure in sand). Roots are slow growing but mycorrhizal fungi proliferate and ramify through the soil. Symbiotic relationship: carbon-nitrogen exchange .

18. Mineral soils The concentration of dissociated water in freshly-distilled water is 10 -7 M. This is used to describe acidity-alkalinity, originally called the pouvoir Hydrogéne, which we know now as pH. ACIDEZ DEL SUELO determinará CÓMO estarán disponibles Nutrientes disponibles a través del AGUA DEL SUELO Small quantities of water molecules dissociate : pH = - log [H + ] = - log [10 -7 M] = 7 for fresh distilled water Small values for acid , e.g., the water in Sphagnum bogs can be ~3 Large values for alkaline , e.g., soils on limestone ~8 Suelos Minerales H 2 O OH - + H +

19. How clay particles provide nutrients The root hair cells of plant roots secrete H + into the water around nearby clay particles. These smaller H cations replace the larger macro- and micro-nutrient cations: The released cations are now available for uptake into roots. A clay particle (much enlarged here) is covered with negative charges, anions: Opposites attract, so metal ions with positive charge(s), cations, stick all over the surface of the clay particle: 2H + Ca 2+

20. Summary of soil water chemistry In this summary occurrence of H+ in soil water is shown as the result of respiration of CO 2 and disassociation of carbonic acid H 2 CO 3 that forms Water flow

22. Uptake of water and nutrients by roots See Equivalent Fig. 32.2B

23. Film clip

24. 4.Problems in plant nutrition Plant Nutrient Type Visual symptoms Nitrogen Deficiency Light green to yellow appearance of leaves, especially older leaves; stunted growth; poor fruit development. Excess Dark green foliage which may be susceptible to lodging, drought, disease and insect invasion. Fruit and seed crops may fail to yield . Phosphorus Deficiency Leaves may develop purple coloration; stunted plant growth and delay in plant development. Excess Excess phosphorus may cause micronutrient deficiencies, especially iron or zinc. Potassium Deficiency Older leaves turn yellow initially around margins and die; irregular fruit development. Excess Excess potassium may cause deficiencies in magnesium and possibly calcium. W.F. Bennett (editor), 1993. Nutrient Deficiencies & Toxicities in Crop Plants, APS Press, St. Paul, Minnesota. Excess frequently operates through imbalance

25. 5. Nitrogen and the effects of soil organic matter on plant nutrition Nitrogen is the element most required by plants, in terms of weight. It is not a product of weathering of soil particles. There are two sources: fixation of atmospheric nitrogen by bacteria decomposition of organic matter, usually decaying plant material.

26. N-fixing bacteria Fig. 32.13 Most uptake from the soil is in the form of nitrate

27. Spodic soil Organic material is important in agricultural soils both as a source of nitrogen and because it can increase water holding capacity, e.g. biosolids application effects A characteristic of non-agricultural soils is accumulation of organic material and acidification of the soil. Such soils typically develop a very distinct stratification, with organic mater at the top. The organic layers in such soils can have a considerable total quantity of nitrogen but little may be available due to the high acidity, and sometimes lack of oxygen, in the organic layer.

28. Basic Soil-Plant Relationships Organic Matter & Biota Exchangeable ions Surface adsorption Solid phases & Minerals Nutrient Uptake by Plants Soil Solution Soil Air Rainfall, Evaporation, Drainage, Addition of Fertilizer

33. Activity vs Concentration in Soil Solution 0.0085 0.0255 Al 3+ 0.42 0.75 SO 4 2- 4.26 4.98 NH 4 + 2.23 2.60 K + 0.43 0.71 Mg 2+ 0.98 1.68 Ca 2+ mM mM Activity Concentration Ion

35. Quantity and Intensity Quantity Intensity Crop Uptake Fertilizer

37. Quantity and Intensity >>> Buffer Capacity <<< Quantity Intensity Crop Uptake Fertilizer

39. Buffer Capacity Quantity/Intensity Graph (Q/I) Intensity Quantity Soil A Soil B

41. Basic Soil-Plant Relationships Organic Matter & Biota Exchangeable ions Surface adsorption Solid phases & Minerals Nutrient Uptake by Plants Soil Solution Soil Air Rainfall, Evaporation, Drainage, Addition of Fertilizer

42. The indissoluble link between man and soil is manifest in the very name Adam, derived from Adamiss – a Hebrew noun of feminine gender meaning earth or soil. Adamiss’ name encapsulated ‘maniss,’ meaning origin and destiny: his existence and livelihood derive from the soil to which he is tethered throughout his life and to which he is fated to return at the end of his days. Likewise, the name of Adam’s mate, Hava (rendered ‘Eve’ in translation) literally means ‘living’. Together, therefore, Adam and Eve signify 'Soil and Life.” from “Out of the Earth: Civilization and the Life of the Soil&quot; by Dr. Daniel Hillel , professor emeritus of plant, soil, and environmental sciences at the University of Massachusetts, Amherst. existe un vínculo indisoluble y estrecho entre el hombre y el suelo, que se manifiesta en el nombre ADAN, derivado del hebreo ADAMISS(= sustantivo femenino = tierra o suelo);maniss&quot;contenido en Adamiss, significa origen y destino: por lo tanto la vida y existencia del hombre en gral.derivarían del suelo al cual está ligado a traves de su vida y al que está destinado a regresar al final de sus días. De la misma forma, su compañera, HAVA (EVE) literalmente significa vida. De esta forma, ADAN y EVA,---------> SUELO y VIDA SON