Aims of the research: Setting an equation to determine the amount of K fertilizers apllied for sugarcane based on a nutrient balance, creating background knowledges for a sustainable management of K for each specific
area, contributing to improve productivity, quality and efficiency of cane production in Lam Son hilly
regions of Thanh Hoa.
HIGHER PLANTS ARE AUTOTROPHIC ORGANISMS that can synthesize their organic molecular components out of inorganic nutrients obtained from their surroundings. For many mineral nutrients, this process involves absorption from the soil by the roots (see Chapter 5) and incorporation into the organic compounds that are essential for growth and development. This incorporation of mineral nutrients into organic substances such as pigments, enzyme cofactors, lipids, nucleic acids, and amino acids is termed nutrient assimilation....
Part II: Soil fertility and fertilizing 8 Introduction and nutrient balance
To ensure a sufficient nutrient supply for crops, we must strive to keep an even nutrient balance in the soil. The loss of nutrients has to be minimised, and the addition of nutrients maximised in order to avoid a depletion of nutrients in the soil.
Soil fertility is critical for the provision of adequate food, fiber and renewable natural
resources(fuel,wood etc.). In the developing world soil fertility is linked to economic well
being of many farm families. Poor soils means poor harvest leading to low returns for the
over 60% of the population of developing countries relying on agriculture for survival.Use
of inorganic and organic fertilizers in addition to biological processes to improve the fertility
of the soil requires good understanding of their practical use and management.
MINERAL NUTRIENTS ARE ELEMENTS acquired primarily in the form of inorganic ions from the soil. Although mineral nutrients continually cycle through all organisms, they enter the biosphere predominantly through the root systems of plants, so in a sense plants act as the “miners” of Earth’s crust (Epstein 1999). The large surface area of roots and their ability to absorb inorganic ions at low concentrations from the soil solution make mineral absorption by plants a very effective process.
IN CHAPTER 5 WE DISCUSSED plants’ requirements for mineral nutrients and light in order to grow and complete their life cycle. Because living organisms interact with one another and their environment, mineral nutrients cycle through the biosphere. These cycles involve complex interactions, and each cycle is critical in its own right. Because the amount of matter in the biosphere remains constant, energy must be supplied to keep the cycles operational. Otherwise increasing entropy dictates that the flow of matter would ultimately stop.
SURVIVAL ON LAND POSES SOME SERIOUS CHALLENGES to terrestrial plants, foremost of which is the need to acquire and retain water. In response to these environmental pressures, plants evolved roots and leaves. Roots anchor the plant and absorb water and nutrients; leaves absorb light and exchange gases. As plants increased in size, the roots and leaves became increasingly separated from each other in space. Thus, systems evolved for long-distance transport that allowed the shoot and the root to efficiently exchange products of absorption and assimilation.
PLANT CELLS ARE SEPARATED from their environment by a plasma membrane that is only two lipid molecules thick. This thin layer separates a relatively constant internal environment from highly variable external surroundings. In addition to forming a hydrophobic barrier to diffusion, the membrane must facilitate and continuously regulate the inward and outward traffic of selected molecules and ions as the cell takes up nutrients, exports wastes, and regulates its turgor pressure.
THE CYTOKININS WERE DISCOVERED in the search for factors that stimulate plant cells to divide (i.e., undergo cytokinesis). Since their discovery, cytokinins have been shown to have effects on many other physiological and developmental processes, including leaf senescence, nutrient mobilization, apical dominance, the formation and activity of shoot apical meristems, floral development, the breaking of bud dormancy, and seed germination.
Food and water are necessary to keep the human body functioning. People
must have a balanced diet that includes a complex range of nutrients to provide
energy, promote growth, maintain health and resist disease or illness, and
It is also known that food and water can carry, or be sources of, harmful
microorganisms, chemical compounds and particulate matter.
In the first volume of this two-volume book,
Advanced Nutrition: Macronutrients
for the macronutrients were discussed. The absorption, metabolism, excretion, and function of the
various sources of energy as well as detailed discussions of the need for water and energy balance
were presented. The needs for the micronutrients, as well as explanations of how these nutrients
function in the body, were deferred to this, the second volume.
In India, rice, wheat and maize yields per hectare of land have increased three to
four fold between 1950 and 2010, mainly due to the adoption of improved agronomic
practices. Egg production now ranges between 310–320 per annum per bird. Similarly,
feed conversion efficiency in broilers is also at par with developed nations and Indian
poultry farmers are now more conscious of the need to increase profits by cutting costs
and improving productivity. Balancing of nutrients in poultry rations along with improved
mineral supplementation has led to this improved productivity.
Because of the threepart process used to develop and
communicate the 2005 Dietary Guidelines, this publication
and the report of the DGAC differ in scope and purpose
compared to reports for previous versions of the Guidelines.
The 2005 DGAC report is a detailed scientific analysis that
identifies key issues such as energy balance, the conse
quences of a sedentary lifestyle, and the need to emphasize
certain food choices to address nutrition issues for the