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Soil test

In agriculture, a soil test is the analysis of a soil sample to determine nutrient content, composition and other characteristics, including contaminants. Tests are usually performed to measure the expected growth potential of a soil. It measures fertility, indicates deficiencies that need to be remedied and determine potential toxicities from excessive fertility and inhibitions from the presence of non-essential trace minerals. The test is used to mimic the function of roots to assimilate minerals. The expected rate of growth is modeled by the [http://books.google.com/books?id=iP7LWpn5oJ0C&pg=SL4-PA89&lpg=SL4-PA89&dq=%22law+of+maximum%22+wallace&source=bl&ots=rUUDE5U2SD&sig=4OKtubPJivYnLzM4QhHT_mbV52k&hl=en&ei=rJRBTaWLKYiCsQP9sc3_Cg&sa=X&oi=book_result&ct=result&resnum=3&sqi=2&ved=0CCQQ6AEwAg Law of the Maximum].

Soil sampling

The quality of the original soil sample plays a key role in determining the practical value of test results. Most labs will provide documentation outlining the proper procedures for collecting soil samples.

Labs, such as Iowa State and Colorado State University, recommend that you take between 10-20 samples for every 40|acre|m2 of the field. Sampling implements must be properly cleaned prior to sampling, and must be cleaned between samples to avoid cross-contamination (especially when sampling and testing for soil contaminants). The tool should be free of rust, and washed with distilled water. Doing so will clean the tool, but also not add any minerals or elements from regular tap water or chemicals that could change the composition of the soil.

Soil characteristics can vary significantly from one spot to another, even in a small garden or field. Taking samples everywhere in the field is crucial to get the most accurate measurement of nutrients and other organisms. An example of this is along gravel roads where the soil could have more lime from the dust from the roads settling down in the soil, or an old animal feedlot where phosphorus and nitrogen counts could be higher than the rest of the field.

Sample depth is also an important factor. It is recommended that you take the samples from tillage depth, as this is where the majority of the nutrients and elements are placed mechanically. The presence of various nutrients and other soil components varies during the year, so sample timing may also be important. A good time to take a sample for testing is in the fall after harvesting is finished, but this isn't the only time it should be done.

Sampling and testing in the fall is beneficial because the producer will get the results back in time to formulate the fertilizer plan for the following growing season. Another time sampling and testing can be done is spring. This is a good way to see what nutrients survive over winter when the soil freezes, as well as if any leaches away from melting of snow and thawing of the soil. This way the producer can know if more or less fertilizer needs to be purchased.

Mixing soil from several locations to create an "average" (or "composite") sample is a common procedure but it must be used judiciously as it can artificially dilute quantities/concentrations of soil components and may not meet government agency requirements for sampling. Make a reference map for your filing system so you know where you took them, and how many samples you took in the field. All of these considerations affect the interpretation of test results.

Storage and handling

Because certain characteristics of soil change with time it is essential that soil is analyzed as soon as practical. If it can not be tested within 24 hours of sampling soil should be frozen to reduce changes due to biological and chemical activity. Longer periods between sampling and testing may require the soil to be air dried. Properly dried soil may be stable for periods of 6 months or more.

Soil testing

Soil testing is often performed by commercial labs that offer an extensive array of specific tests. Choosing the test lab site is just as important as the test results. There are many soil testing labs in the United States, but finding the right one for you will take some research. It is most beneficial for the producer to find the local most lab, as the workers will have a greater knowledge and more experience working with the local soils.

Tests include, but aren't limited to, major nutrients - nitrogen (N), phosphorus (P), and potassium (K), secondary nutrients - sulphur, calcium, magnesium, minor nutrients - iron, manganese, copper, zinc, boron, molybdenum, aluminum.

Soil testing can be an easy, cost effective way to manage agronomic as well as horticultural soils. It tells key nutrient levels, as well as pH levels, so the producer can make the best choice when purchasing fertilizers and other nutrients.

Recently (2004) new prepaid mail-in kits have come to market that offer two specific benefits to small acreage farmers, urban homeowners and the lawn care industry: first is an inexpensive and quick manner to transfer soil samples directly to an accreditted laboratory for analysis; and second, the process translates raw data findings (as listed above: Tests include,...") into workable and practical nutrient management/fertilizer reports. One such kit can be viewed at [http://www.grass-roots.ca Grass Roots]. This particular process provides an actual 'prescription' of fertilizers that are readily available in the global market for two complete seasons.

Less comprehensive do-it-yourself kits are also available, usually with tests for three important plant nutrients - nitrogen (N), phosphorus (P), and potassium (K) - and for soil acidity (pH). Do-it-yourself kits can usually be purchased at your local cooperative or through the university or private lab you choose. Prices of the tests will vary on the lab/university you purchase it from and also on what kind of test you want to do. Lab tests are more accurate, though both types are useful. In addition, lab tests frequently include professional interpretation of results and recommendations. Always refer to all proviso statements included in a lab report - these may outline any anomalies, exceptions and shortcomings in the sampling and/or analytical process/results.

lettuce) and on the surface of root crops (e.g., carrots)." [http://www.extension.umn.edu/distribution/horticulture/DG2543.html UMinn]

Lead Level / Extracted Lead (ppm) / Estimated Total Lead (ppm)

Low / less than 43 / less than 500*
Medium / 43 to 126 / 500 to 1000
High / 126 to 480 / 1000 to 3000
Very High / greater than 480 / greater than 3000
(*) If estimated total soil lead levels are above 300 ppm, however, young children and pregnant women should avoid soil contact.

Good Gardening Practices to Reduce the Lead Risk

1. Locate gardens away from old painted structures and heavily traveled roads.<


From Yahoo Answers

Question:I would like to know what factors effect soil pH... aspects that can be tested from the point of view of a chemist, environmentalist, bioligist and physicist. Thanks

Answers:Factors affecting soil pH The pH value of a soil is influenced by the kinds of parent materials from which the soil was formed. Soils developed from basic rocks generally have higher pH values than those formed from acid rocks. Rainfall also affects soil pH. Water passing through the soil leaches basic nutrients such as calcium and magnesium from the soil. They are replaced by acidic elements such as aluminum and iron. For this reason, soils formed under high rainfall conditions are more acidic than those formed under arid (dry) conditions. Human distractions like pollution alter the pH of soil. Researches have also revealed that soil pH is affected by the vehicular and ongoing traffic. This largely hampers the soil pH and in turn the primary productivity by compacting the soil and decreasing its friability. Application of fertilizers containing ammonium or urea speeds up the rate at which acidity develops. The decomposition of organic matter also adds to soil acidity A pH level of around 6.3-6.8 is also the optimum range preferred by most soil bacteria, although fungi, molds, and anaerobic bacteria have a broader tolerance and tend to multiply at lower pH values. Therefore, more acidic soils tend to be susceptible to souring and putrefaction, rather than undergoing the sweet decay processes associated with the decay of organic matter, which immeasurably benefit the soil. These processes also prefer near-neutral conditions.

Question:I want to know how does present of quarry affects the abiotic factors in soil ? here's the question that i needed to be answer, please everyone Q1: How does quarry affects soil pH ? Q2: How does quarry affects soil moisture ? Q3: How does quarry affects soil organic matter (humus content) Q4: How does quarry affects soil porosity and permeability

Answers:Quarry is excavation of rock, or ot may be referred to as the ground rock taken from stne, and that part present inj a sample of soil. So, since rock and stone are mineralized, they don't really significantly affect pH in soil. They would possibly absorb moisture, such as pea gravel which heps drainage due to the high surface area coverage for water to be absorbed - also like sand on a ballfield helps drainage. Humus is basically decomposed organic plant matter, and is high in organic acids, so the"quary" would help stabilize the pH and slightly help reduce acidity. The last question is the best purpose of "quarry" or ground rock. it increases te posrosity of soil, and makes it more permeable. Again, another reason it is good for ballfields to absorb water and keep us playing ball soon after rain.

Question:

Answers:think you're in the wrong catagory. thanks for the 2 points

Question:What are some ABIOTIC (nonliving) unique factors that affect transpiration in plants? I know the easy ones: temperature humidity pressure light soil water content pH wind What are some unique factors: Like maybe sound waves per se

Answers:you have mentioned all the factors in your question ; beyond that there is ; as yet no other factor that affects transpiration .