The four main components of soil are rocks minerals, water, air and organic material leaves and decomposed animals, for. Vermiculture has become a major component in biological farming, which is found to be. Soil organic matter is composed of plant and animal tissue within the soil at different stages of decomposition. Persistence of soil organic matter as an ecosystem property. Organic particles are the result of both plants and animals inhabiting the area. Functions of soil organic matter and the effect on soil. Soil organic matter and its benefits north central region water. Soil organic matter is the fraction of the soil that consists of plant or animal tissue in various stages of breakdown decomposition. Soil organic matter acts like a sponge to hold water, even from the atmosphere, where it. Chemical and physical characteristics of compost leachates. Soil science society of america journal abstract division s. Building soil organic matter with organic amendments. The chemical composition of the soil, the topography, and the presence of living organisms determines the quality of soil. Organic matter is a reservoir of nutrients that can be released to the soil.
Major components of soil organic matter soil organic matter is a diverse mixture that includes living plant roots, the soil biomass, and partially degraded plant, animal, and microbial components. Population size of root nodule bacteria with different crop rotations 32 11. Pore spaces are the voids between the soil particles. Although these three elements make up about 92% of the dry weight of the organic matter in soil, other elements are very important for the nutrition of plants, including nitrogen, phosphorus, potassium, sulfur, calcium, magnesium, and. Mineral it is the largest component of the soil and makes about 45% of the soil. These include, in varying proportions and many intermediate stages, an active organic fraction including microorganisms 1040 percent, and resistant or stable organic matter 4060 percent, also referred to as humus. Soil physical properties are then addressed, including texture, structure, organic mat. Soil organic matter soil degradation has become a major concern in canada. We collected soils from a rowcrop maizesoybean rotation field experiment replicated across three sites in the north central and midatlantic united states. Soil organic matters mainly derive from plants and microorganisms, including living and dead organisms, as well as its secretion and derivatives. This factsheet deals with the role of organic matter in soil productivity and the effects of various management practices on soil organic matter. Composition of soil soils have four major components.
This distinguishes it from organic matter that has been in soil longer, which is denser and sinks in water. Specifically, ph influences solubility and availability of plant nutrients, performance of pesticides which include herbicides, and organic matter decomposition. Soil organic matter an overview sciencedirect topics. Soil is a mixture of organic and inorganic constituents.
The characterization of plant and soil components relative to their turnover in nature has been stressed. The inorganic components come from the weathering of various rock types. The importance of soil organic matter key to droughtresistant soil and sustained food production fao soils bulletin fao soils bulletin 80 8 0 f a o t h e i m p o r t a n c e o f s o i l o r g a n i c m a t t e r k e t o d r o u g h tr e s i s t a n t s o i l a n d s u s t a i n e d f o o d p r o d u c t i o n 80 i s s n 0 2 5 32 0 5 0. Organic matter acts as glue causing soil particles to clump together into structural units soil structure. Most of our productive agricultural soils have between 3 and 6% organic matter. In general, soil contains 4045% inorganic matter, 5% organic matter, 25% water, and 25% air.
The fifth component of soil, which isnt always recognized, is the living world that exists under the ground the biological component. Soil structure and soil organic matter request pdf. Soil organic matter contributes to soil productivity in many different ways. Reduction of dry matter of different cover crops 22 10. Soil organic matter som is the organic component of soil, consisting of three primary parts including small. Temperature responses of individual soil organic matter components 54 3. Quality of fresh organic matter affects priming of soil organic matter and substrate utilization. This accounts for the amount oforganic material returned to the soil. It is called light fraction organic matter because it floats on the surface of water. Instruct students to record the four components of soil and the basic characteristics of soil texture in their guided notes. Active soil organic matter also referred to as detritus.
These groups are not static entities and dynamic interactions occur between these three major components. Soil organic matter can be separated into three basic components to provide a proper discussion of its benefits and management strategies in a notill system. Organic matter in notill production systems oklahoma state. Please view the pdf by using the full text pdf link under view to the left. Soil is a dynamic natural body having properties derived from the combined effects of climate and biotic activities, as modified by topography, acting on parent materials over time. Climatic conditions, such as rainfall, temperature, moisture, and soil aeration oxygen levels affect. While some soil has only one particle type, the most fertile soil is a mixture of several organic and inorganic components. A soil is simply a porous medium consisting of minerals, water, gases, organic matter, and microorganisms. Components of soil organic matter and their functions. Spectroscopic response of soil organic matter in mining area.
The different components of soil organic matter decompose at different rates. Each percent of organic matter in the soil releases 20 to 30 pounds of nitrogen, 4. Soil organic matter consists of a variety of components. Rich garden soil is approximately 45 percent rocks and minerals, 5 percent.
Soil organic matter, the essence of the fertility of soil, which has a great effect on physical, chemical, and biological properties of soil, is an indicator of good or bad, rich or poor soil. Soil organic matter is a very important part of the composition of a healthy soil. Key functions of soil organic matter soil organic matter som plays a number of key roles in terrestrial ecosystems and agroecosystems, as related to the three components of soil quality and fertility. Soil organic matter also helps protect our soils from erosion losses, which is important because soil is a nonrenewable resource. Soil organic matter includes all organic or carboncontaining substances within the soil. Soil organic matter matters european commission europa eu. Soil organic matter is responsible for maintaining a healthy, productive soil by providing food and a house for microbes which run the show in the world beneath our feet. The importance of soil organic matter home food and. Inherent factors affecting soil organic matter inherent factors affecting soil organic matter such as climate and soil texture cannot be changed. We found that soil as was improved and maintained with time more by hydrophobic than by hydrophilic components of organic matter. A property of a soil rich in organic matter is ample pore space between the structural units, which is very desirable in helping to aerate the soil.
Light fraction organic matter is the recently added and partially decomposed organic matter. Major components of organic farming are crop rotation, maintenance and enhancement of soil fertility through biological nitrogen fixation, addition of organic manure and use of soil microorganisms, crop residues, biopesticide, biogas slurry, waste etc. Live and dead earthworm numbers per square metre at 015 cm of soil depth sampled immediately after treatment 33 12. Aug 01, 2001 organic matter is a reservoir of nutrients that can be released to the soil.
These percentages are only generalizations at best. Soil is made up of three main components minerals that come from rocks below or nearby, organic matter which is the remains of plants and animals that use the soil, and the living organisms that reside in the soil. The typical soil consists of approximately 45% mineral, 5% organic matter, 2030% water, and 2030% air. The basic components of soil are minerals, organic matter, water and air. This is because of the ways in which clay helps to stabilise organic matter in soil. Basic soil components climate, forests and woodlands. The composition and proportion of these components greatly in. Soil organic matter som is the organic component of soil, consisting of three primary parts including small fresh plant residues and small living soil organisms, decomposing active organic matter, and stable organic. Baldock and others published soil organic matter find, read and cite all the research you need on researchgate. For further information go to interpreting soil colour what does soil colour tell us.
The key functions of som will decline unless there is continuous turnover of plant. Longlasting aggregate stability of soils can be thus achieved by addition of hydrophobic humic material with hydrophobic organic wastes. Soil is comprised of minerals, soil organic matter som, water, and air figure 1. Soil organic matter som has been considered as the main factor that controls the bioavailability and chemical behavior of heavy metals exposed to environment zeng et al. Worldwide soil organic carbon soc is one of the major pools of carbon. Organic matter is a primary indicator ofsoil quality and an important factor in carbon sequestration and global climate change.
Pdf the persistence of organic matter in soil is now thought to be a result primarily of. The four main components of soil are rocks minerals, water, air and organic material leaves and decomposed animals, for example. The nutrient release occurs predominantly in the spring and summer, so summer crops benefit more from organic matter. Soil organic matter lsu school of plant, environmental and soil. We briefly summarize the biochemical processes occurring during composting and the use and applications of compost in the environment. Evaluation of the organic matter content of a soil in parana 20 9. In this fact sheet, we describe the various components of organic matter and the different roles organic matter plays in soil productivity. Air andor water occupy approximately half the volume of soil. Although surface soil approximately the top 4 to 6. Soil organic matter is the organic component of soil.
We also discuss field management practices that will help preserve or increase soil organic matter levels over time. The percentage of the components vary from time to time. Soil organic matter content is key for a healthy and highquality. Some of the worlds most fertile soils tend to contain high amounts of organic matter. Mineral matter derived from the constituents of the parent material. Erosion, salinization, acidification and loss of organic matter are the main forms of soil deterioration. The dry matter consists of complex organic matter that is composed primarily of carbon, oxygen, and hydrogen. As a result of the differences in active surface area linked to cec, the natural levels of organic matter held in a sandy soil are much lower than in a soil with more clay.1355 1314 11 129 1534 1399 1416 685 1465 1103 1035 210 1451 386 317 1245 478 485 398 1094 1383 306 271 1411 748 513 1561 1063 510 1225 299 668 1083 947 1124 230 1205 194 1327 255 466