Reasons for decline in soil fertility

Slides:

Advertisements

Similar presentations

Let’s Get Down and Dirty!

Advertisements

Soil Salinity/Sodicity/Alkalinity and Nutrients

Desertification: Degrading Drylands About one-third of the world’s land has lost some of its productivity because of drought and human activities that.

Cover Crops and Biofuels Implications for Soil Characteristics and Plant Development Deanna Boardman October 21, 2009.

Formation and Characteristics of Hawaii’s Soils

Chapter 15/14 Soil Resources. Soil  Uppermost layer of Earth’s crust that supports plants, animals and microbes  Soil Forming Factors  Parent Material.

What is it? - Production of food through the growing of plants (Cultivation) Why do we need it? - Population growth leads to high demand for food - 10%

Soil Quality Test Kit Tony Ingersoll NRCS Tri-State Natural Resources Technology Team.

Human Impacts on Soil “The Dirt on Dirt”. Degradation Light - about 700 million ha Moderate - about 900 million ha (size of China) Severe - about 300.

Presentation By Secretary (Fertilizers) National Conference on Agriculture for Rabi

Human Population, Carrying Capacity, and Resource Use 3.4 The Soil System.

APES Ms. Tooker   Rock cycle  Formation  Composition  Physical and chemical properties  Main soil types  Erosion  Soil conservation Soil.

AP Environmental Science Soil Resources (Ch 14) Living in the Environment, 14th edition, G. Tyler Miller.

Chapter 12: Farming and the Environment. How Agriculture Changes the Environment Agriculture one of our greatest triumphs and sources of environmental.

Advance Desertification AGR 740 Advance Desertification AGR 740 Dr. Refaat Abohassan.

Chapter 12 Soil Resources. Soil Problems o Soil Erosion Def: wearing away or removal of soil from the land Def: wearing away or removal of soil from the.

Soil. Chemistry Review Cation: atom that forms a positive charge (example: Ca +2 ) anion: atom that forms a negative charge (example: S -2 )

Soil Productivity and Conservation THE GMIS. Importance of Soil As the key resource in crop production It supports the physical, chemical, and biological.

Unit 4 Soil Science. Importance of Soil What is soil? Holds water and nutrients for plants Natural filter Stores and recycles nutrients Fertile soil =

Importance & Formation of Soil. Importance of Soil Much of the United States ’ success is due to the productive capacity of the soil – U. S. produces.

Soil Electrical Conductivity

Sustainable Food Production. Questions for Today: What is Soil? What is Soil Erosion? What is desertification, salinization, waterlogging? What are ways.

Overview and importance of soil fertility. A fertile soil is one that contains an adequate supply of all the nutrients required for the successful completion.

Reasons for decline in soil fertility.  As crop yields have increased over the years due to the technological changes, many soils are unable to supply.

Soil pH Unit: Soil Science. Objectives O Define: acidity, alkalinity, buffering capacity, soil pH O List and describe inherent factors that affect soil.

3.4 The Soil System.  Outline how soil systems integrate aspects of living systems.  Compare and contrast the structure and properties of.

Soil Respiration Unit: Soil Science. Objectives O Define: soil respiration and soil microbes O Explain the role of soil respiration in determining soil.

Unit C1. Basic Principles of Agricultural/Horticultural Science.

Nitrogen fertilizer use efficiency in rice. Contents  Introduction  Nitrogen dynamic in lowland rice soil  Methods of Nitrogen losses from rice fields.

Chapter 14 Soil Resources. Soil  Uppermost layer of Earth’s crust that supports plants, animals and microbes  Soil Forming Factors  Parent Material.

Organic Matter The key to healthy soils Fred Magdoff Dept. of Plant & Soil Science University of Vermont.

AP Environmental Science Soil Resources Living in the Environment, 14th edition, G. Tyler Miller.

Global Trend: Where Did All the Farms Go? Poor farming practices = loss of soils and farmland  Erosion  Salinization Development in United States = loss.

Soils Chapter 5. SOIL Is the soft material that covers the surface of the earth and provides a place for the growth of plant roots. It also contains minerals,

14 Soil Resources.

Organic Matter The key to healthy soils Fred Magdoff Dept. of Plant & Soil Science University of Vermont.

Global Change Impacts on Rice- Wheat Provision and the Environmental Consequences Peter Grace SKM - Australia Cooperative Research Centre for Greenhouse.

Food and Agriculture How to feed the ever expanding population Currently 5.8 billion 30 years 12 billion.

 Plants and Soil  Soil Degradation  Addressing Soil Degradation.

From Bedrock to Soil.

Salinisation Soil salinisation is one of the major threats in irrigation agriculture. Soil salinity causes yield losses and can lead to structural instability.

Unit C. Basic Principles of Agricultural/Horticultural Science.

TYPES OF FOOD SUPPLY Crop lands – 76 % of the world’s food Range lands – 17 % of the world’s food Oceans – 7 % of the world’s food MAJOR FOOD SOURCES.

After successful completion of this Lesson, you have learned to: List the 3 indicators of soil health. List the physical indicators that help to know a.

1. Explain why soil degradation happens. 2. Discuss the environmental and socio-economic impacts of soil degradation. 3. Discuss how soil degradation can.

You have learnt from the lessons in the earlier Modules that soil properties influence soil health. These soil properties in turn are affected by the agricultural.

Causes Of Soil Degradation IB SL. Soil Problems The main issue is that soils take thousands of years to develop but are very quickly ruined by human actions.

Soil as a System. Soil formation is slow and complex Parent material—base geological material in a particular location, can include lava or volcanic ash,

Soil is a System. How do soils form? Mineralization: decomposition or oxidation of the chemical compounds in organic matter into plant-accessible forms.

Ag Production and the Environment

THE EARTH’S RESOURCES AND POLLUTION. Soil Degradation Scientist’ studies and the experiences of farmers have shown that the most productive soil, or the.

Soil horizons Farming Techniques Erosion Soil Particles.

Sustainable Agriculture Practices. Conventional tillage  incorporates most of the previous crop’s residue into the ground  leaves the surface exposed.

Soil and Climate. Learning Objectives 2)Soil and Climate a)Assess the significance of Solar Radiation to plant growth b)Illustrate the hydrological cycle.

FERTILIZERS, CHLORINATION DEODORIZERS, BACTERIAL FORMULATION.

Lesson 7. Understanding Soil Degradation. Next Generation Science/Common Core Standards Addressed ! HS-ESS2-2 Analyze geoscience data to make the claim.

Integrated Nutrient Management (Nutrient Management Plan ) A Series of Lecture By Mr. Allah Dad Khan.

Reasons for decline in soil fertility

Soil Soil is a mixture of organic matter and broken down rocks. Often containing sand, clay, and water, it acts as an ecosystem for thousands of organisms.

CHAPTER 2 NATURAL RESOURCES AND THEIR CONSERVATION LAND RESOURCE.

Soil Bulk Density/Moisture/Aeration

Problems of Desertification and Degradation

Soil Degradation & Conservation

13.6 Soil Profile The soil profile is a series of horizontal layers of different chemical composition, physical properties, particle size, and amount of.

Topic 5: soil & terrestrial food production systems

RLO 5 Lesson: Overview and importance of soil fertility

Soil Soil is a mixture of organic matter and broken down rocks. Often containing sand, clay, and water, it acts as an ecosystem for thousands of organisms.

Sustainable Agriculture Practices

The Impact of Agriculture

Reasons for decline in soil fertility

Presentation transcript:

Reasons for decline in soil fertility

Reasons for decline in soil fertility Introduction Soil fertility is a component of overall soil productivity that deals with its available nutrient status, and its ability to provide nutrients out of its own reserves and through external applications for crop production.

Reasons for decline in soil fertility Causes of decline in soil fertility Loss of top soil by erosion Nutrient mining Physical degradation of soil (poor structure, compaction, crusting and waterlogging etc. Decrease in organic matter content and soil bioactivity Loss of nutrients through various routes Soil acidification, salinization and alkalinization Inefficient soil management Soil pollution

Reasons for decline in soil fertility Loss of top soil by erosion The top soil is rich in nutrients and organic matter. Loss of the fertile topsoil components through erosion by water and wind results in decreased fertility. Soil erosion is very common in many parts of the country. The basic causes of soil erosion are the result of human activities such as deforestation, overgrazing and poor soil management.

Reasons for decline in soil fertility 2. Nutrient mining Removal of more nutrients by crops than added through manures or fertilizers is called as nutrient mining or depletion. At present, nutrient mining is a major threat to productive sustainable farming. It is a widespread problem in low- and medium input agriculture. Nutrient mining is accelerated by imbalanced fertilization.

Reasons for decline in soil fertility 3. Physical degradation of soil Physical degradation of soil (poor structure, compaction, crusting and waterlogging) reduces soil fertility. Soil structure is a variable soil property that, from an agronomic point of view, can improve or deteriorate. High disturbance of soils (tillage) often results in some structural deterioration, which can be reversed to different degrees.

Reasons for decline in soil fertility 2. Nutrient mining It results in the exhaustion of any nutrient required in moderate to large amounts. Nutrient mining could be severe in the case of N, P, K and S depending on soil nutrient reserves and the amounts replenished. The problem is more acute in areas where high yielding varieties of crops are being cultivated

Reasons for decline in soil fertility 3. Physical degradation of soil Soil compaction decreases the number of large pores (> 100 μm) and, as these are the ones through which roots grow most easily, compaction can have an adverse effect on root growth (see Figure). Figure (on the left) Root growth in a soil with no mechanical impedance problems Root growth in a soil with mechanical impedance problems Waterlogging causes loss of N through denitrification of nitrate.

Reasons for decline in soil fertility 4. Decrease in organic matter content and soil bioactivity The decreased levels of organic matter causes a strong reduction in soil fertility as it plays several roles in soil. Decreased organic matter levels results in poor physical , chemical and biological properties. The microbial activities in soil decrease due to reduced levels of organic matter. These microbial activities play significant role in nutrient availability and recycling.

Reasons for decline in soil fertility 5. Loss of nutrients through various routes Losses of nutrients from soil can be caused by soil erosion, leaching, crop removal or in the form of gases (as in case of N and to a lesser extent S). Nutrient removal by crop products compared with external nutrient inputs can be similar, higher or lower. Negative nutrient balances result where nutrient removals exceed nutrient additions.

Reasons for decline in soil fertility 5. Loss of nutrients through various routes Excessive rainfall, or excessive irrigation, resulting in the passage of water through the soil profile through deep percolation will carry with it soluble nutrients, particularly nitrate, sulphate and boron, etc. Waterlogging causes loss of N through denitrification of nitrates. Ammonia volatilization from urea and some ammonium-containing fertilizers results in losses of nitrogen from soil.

Reasons for decline in soil fertility Picture: Losses of nutrients through different routes from soil Source: http://wattsupwiththat.com/2009/10/12/fixing-the-nitrogen-cycle-in-climate-modeling/

Reasons for decline in soil fertility 6. Soil acidification, salinization and alkalinization Acidification, salinization or alkalinization causes reduction in soil fertility, and eventually lead to problems of nutrient deficiencies, toxicities and imbalances. Factors responsible for soil degradation are generally interrelated. Iron deficiency in rice at higher soil pH

Reasons for decline in soil fertility 7. Inefficient soil management Poor or inefficient soil management results in decreased soil fertility. Improper crop rotations followed may decrease the soil fertility tremendously. Excessive soil tillage leads to erosion of the soil, which leads to reduced soil fertility.

Reasons for decline in soil fertility 8. Soil pollution Soil pollution caused by indiscriminate use of agro-chemicals and heavy metals reduces fertility of soil by affecting the soil biological properties. The growth of useful soil organisms is adversely affected, which eventually causes a decline in biological soil fertility.