SES-221 Introductroy Soil Science=IIDepartment of Soil & Environmental Sciences Faculty of Agriculture Rawalakot University of Azad Jammu & Kashmir email: email@example.com
Plant NutritionPlants have nutritional requirements just like humans in order to grow, developand complete their life cycle. The supply of nutrients to the plants should bebalanced, ensuring not to over or under-fertilize. Nutrients are classifiedaccording to their importance to plantsSoil Fertility: It is the ability of a soil to supply the essential nutrients for plantgrowth. Or The overall ability of a soil to support vigorous crop growth byensuring adequate plant nutrients and suitable conditions for water uptake, andby providing favorable conditions for root growth and development. Fertility is asynthesis of chemical, physical and biological components and is alsoinfluenced by climatic and management factors.Soil Productivity: It refers to the capacity of the soil to produce a certain yieldof crops with optimum management. Fertility is only one of a number of factorsthat determine the magnitude of yields.Essential Plant Nutrient: “ An element in the absence of which a plant is unable to completeits vegetative or reproductive life cycle” and adequate supply of which is essential foroptimum plant growth. There are 19 elements are considered essential for plantgrowth.
Criteria of Essentiality of a Nutrient1. Element required by plant to complete its life cycle.2. Element needs to be directly involved in the nutrition and plants active metabolisms.3. The need for the nutrient is specific and deficiency of it cannot be corrected by the other element.Deficient: When a nutrient is at such a low concentration that plant growth is retarded resulting in yield reduction. Deficiency symptoms may also be exhibited.Adequate: When concentration of a nutrient is sufficient for optimum growth of plant.Insufficient: When the concentration of a nutrient is slightly below the adequate range required for optimum plant growth and yield. Nutrient deficiency symptoms are are seldom exhibited.Toxic: When the level of an essential nutrient or other element is so high that it causes a severe reduction in plant growth.
Macronutrients: essential elements used by plants in relatively largeamounts(present at least 0.1% in plant dry matter) for plant growth are calledmacronutrients.Micronutrients: These elements are required in relatively less quantities(presentless than 0.1% of pant dry matter) as compare to macronutrients.
Cobalt (Co), Silicon (Si), Sodium (Na) and Nickle (Ni) and vanadium (V) are also essentialfor some higher plants
Mobile Nutrientsdeficiency symptoms appear in the lower older leavesImmobile Nutrientsdeficiency symptoms appear in the upper younger leavesFertilizer Solid, liquid or gaseous material containing one or more fertilizer nutrients more or less immediately available to plants and acting essentially on the chemical component of soil fertility.Balanced fertilization The application of nutrients in proportions best suited to the needs of the crop taking account of the amounts of each supplied by the soil.Farmyard manure (manure, dung) Organic manure consisting essentially of faeces, urine and straw or other litter.Fertilizer requirement The amounts of plant nutrients required by a crop during its growth period, assessed in relation to soil and other growing conditions.