Irrigating a heavy clayey soil and a sandy soil in the same way would result in very different results. Good soil management is critical for crop productivity. Poor management can lead to erosion, loss of fertility, deterioration of soil structure, and poor crop yields.
Tilling : Mechanical manipulation of soil loosens the soil, and promotes aeration, porosity and water-holding capacity. It allows a gardener to incorporate soil amendments such as OM and lime.
On the other hand, tilling tends to decrease aggregation, causing compaction compacted soils are dominated by few, small pores.
It can take years to overcome the damage caused by overtilling. Managing pH : Soil pH regulates the availability of plant nutrients. Soil pH can be lowered by adding some kinds of organic matter or sulfur or sulfates; this is not often needed in Maine soils. Soil pH can be raised by adding lime or some types of fertilizer or wood ash. It is difficult to overcome the negative effects of applying excessive amounts of these materials. Test first! Mulching : Mulch is a material that covers the soil.
Organic mulches such as compost, aged manure or bark chips decompose to supply OM and nutrients in the long term. Inorganic mulches such as stone or plastic sheet materials have little effect on nutrient levels and do not contribute OM to the soil.
All mulches affect soil temperature by insulating or transferring heat, and all mulches help soils retain moisture. Managing OM levels : In natural areas, plants and animals die, decompose and replenish OM in the soil.
On the other hand, in developed landscapes where this natural cycle is interrupted, gardeners must implement processes to replenish soil OM. Leaves from deciduous trees can be left in place to decompose; plant debris can be composted and incorporated back into gardens as OM; and plant residue, green manures and animal manures can be incorporated directly into the soil. Some tillage is generally required to incorporate this material into the soil. Adding huge amounts of OM at one time can cause nutrient problems, especially if the material is not fully composted.
Three elements, carbon, oxygen and hydrogen, are essential to plant growth and are supplied by air and water. The other essential elements are referred to as plant nutrients , and are provided by the soil, or are added as fertilizers, and enter plants almost exclusively through the roots.
These plant nutrients are divided into two groups. Those required by plants in large amounts are called macronutrients ; these are nitrogen, phosphorus, potassium, calcium, magnesium and sulfur. Plant micronutrients , needed in tiny amounts include iron, chlorine, zinc, molybdenum, boron, manganese, copper, sodium and cobalt. Macronutrients and micronutrients are all critical to normal plant growth and development; they are simply needed in different amounts. Organic fertilizer sources include compost, aged manure, rock phosphate, soybean meal, and fish meal.
Cover crops also add OM to the soil. Inorganic fertilizer products are also widely available, either as single-nutrient or multi-nutrient products. Fertilizers are labeled as slow-release or soluble. Slow-release fertilizers provide nutrients over a period of time, as they break down or decompose.
Soluble fertilizers are fast-release, and many are dissolved into water and then irrigated onto crops. Nutrients can be provided by many products and practices. Price, availability, ease of use, needed equipment, time and philosophy should be considered when selecting the best fertilizer and application method for any situation. Occasionally, in severe nutrient deficiency situations, some micronutrients are sprayed onto the foliage of crops, but most are applied to the soil and taken up by roots.
In hydroponic production systems, nutrients are dissolved in water and washed over the exposed roots of plants. Most soils have at least some residual nutrients.
Only a soil test can assess this. Fertilizing without the results of a soil test leads to a waste of money and product, and can exacerbate an existing nutrient imbalance. In addition, sometimes nutrients are present in sufficient supply but are unavailable because of too high or too low pH. A soil test can reveal this, and a soil lab professional or crop consultant can recommend practices to resolve such problems.
Some gardeners do not say that they garden, but rather that they work the soil. This reveals an understanding that good soil conditions are essential to support productive plant growth.
Here are a few gardening tips related to soil management:. To amend a heavy clayey soil, add OM, not sand. To amend a light sandy soil, add OM, not clay. Most ornamental landscape plants woody trees and shrubs, and herbaceous perennials and annuals are best fertilized in spring. Fertilizing late in the season can lead to a late-season flush of growth that does not adequately harden off before winter. Most houseplants are best fertilized at the rate recommended on the product label in spring and summer, and at half that rate in fall and winter.
Side-dressing supplemental nitrogen fertilizer next to growing plants later in the season may be necessary. Manage the pH of garden soil to ensure good nutrient availability. Rotate vegetable crops with cover crops to maintain good levels of organic matter, which helps the soil retain nutrients for plant use. When fertilizing a lawn, determine the level of growth desired.
If a low-maintenance lawn is desirable, no fertilizer may be needed. Slow-release fertilizers are preferred over soluble fast-release formulations. Apply a maximum of 2 pounds nitrogen per square feet per year on established lawns; in most cases, apply half at spring green-up and half in fall before September Avoid fertilizing in midsummer.
Leave an unfertilized buffer strip of at least 25 feet adjacent to lakes, streams, rivers, bays, vernal pools and wetlands. Avoid using phosphorus fertilizer if a soil test reveals phosphorus is not necessary, as phosphorus can cause freshwater quality problems.
Avoid weed-and-feed products, which do not allow the option to adjust the fertilize rate. Avoid compacting soils. Walk on paths, keep garden carts on paths, park in the driveway rather than on the lawn, and avoid walking on one path across a lawn when it is frozen. Never walk on saturated soil. Wait until the garden dries out in spring before planting. Avoid bare soil in your vegetable garden.
When a crop is harvested, replant the area with another crop or plant a cover crop. Each of these components contributes to the vital functions of soil. Bacteria, fungi, protozoa, earthworms, tiny insects, and other organisms form the living fraction of soil organic matter. Much to the surprise of anyone who considers soil to be dead dirt, living organisms compose about 15 percent of total soil organic matter, weighing between 2, and 30, pounds per acre Gugino ; Brady This live fraction of the soil does a host of functions described below.
The second fraction of soil organic matter is the "dead"--fresh residues that have been recently added to soil. This is active, easily decomposed material that provides the fuel for soil organisms.
When fresh SOM is added to the soil, most of it decays to CO 2 , water, and minerals within a few months to years. This process provides energy e. Just like cornflakes provide sugar and carbohydrates for humans, decaying leaves, manure, and plant roots provide sugars and carbohydrates for bacteria, fungi, and the soil food web. Some soil organic matter is very resistant to further decay and can last often bound tightly to clay particles for hundreds of years. This very stable form of SOM is commonly referred to as humus.
In fact, the average humus particle is one thousand years old. Humus is typically about 70 percent of the total SOM in agricultural soils. Humus, in particular, and SOM, in general, are important in enhancing soil nutrient-holding especially cation and water-holding capacities, soil structure and tilth, and general fertility see Illustration Organic matter management is an important part of farming, but our understanding of it is quite elementary.
We know that soil fertility tends to increase with increasing SOM and that continual depletion of SOM eventually leads to very poor soils.
The soil is alive. In just one teaspoon of agricultural soil there can be one hundred million to one billion bacteria, six to nine feet of fungal strands put end to end, several thousand flagellates and amoeba, one to several hundred ciliates, hundreds of nematodes, up to one hundred tiny soil insects, and five or more earthworms.
These organisms are essential for healthy growth of your plants. For example, tiny insects in the soil rip and shred leaves and other organic material, breaking it down into smaller pieces that are then consumed by bacteria and fungi. These bacteria and fungi excrete sticky substances that hold the soil together into aggregates and provide food for an entire web of organisms in the soil.
When these bacteria and fungi are consumed by other soil organisms, like the microscopic worms called nematodes, the nematodes excrete ammonia, an important source of nitrogen for plants. Adding organic matter to soil is essential for all these soil organisms. Cover crops, leaves, compost, and other organic materials that we add to soil are food for these organisms.
Which type of organic material we add to the soil changes which type of organisms will have the largest numbers. For example, adding material very high in carbon will encourage fungi that excrete enzymes such as chitinase, which can break down tough-to-digest material. Illustration Organic Matter Holds Nutrients. Cations held on negatively charged organic matter and clay. Prepared by S. Let's Stay Connected. By entering your email, you consent to receive communications from Penn State Extension.
View our privacy policy. Thank you for your submission! Home Soil Quality Information. Soil Quality Information. Healthy soils yield healthy crops, But what is healthy soil and how do we achieve it? Photo credit: Steve Culman. Healthy, high-quality soil has Good soil tilth Sufficient depth Sufficient, but not excessive, nutrient supply Small population of plant pathogens and insect pests Good soil drainage Large population of beneficial organisms Low weed pressure No chemicals or toxins that may harm the crop Resilience to degradation and unfavorable conditions --from Soil Health Training Manual Remember, soil fertility is only one component of soil quality.
Soil Texture We cannot change certain aspects of a given soil. See Illustration 2 Illustration 2: Particle Size. Differences Between Sand, Silt, and Clay You are probably familiar with the characteristics of a clay soil. Soil Structure In pursuit of high-quality soil we generally try to build highly "structured" soils.
Soil Aggregates The aspect of soil structure that often interests us most as soil managers and that we can most easily change is soil aggregation. Gugino Illustration 6: Soil Aggregate. Why Does It Matter? Compaction When soil has poor structure or we mistreat it, we compact the soil. Illustration 8: Plant growth is limited in compacted soils. Water-Holding Capacity High-quality soils have a high available water-holding capacity.
Organic Matter Soil organic matter SOM is a complex of diverse components, including plant and animal residues, living and dead soil microorganisms, and substances produced by these organisms and their decomposition. Soil Biota The soil is alive. References Brady, N.
The Nature and Properties of Soils. Upper Saddle River, N. Doran, J. Defining Soil Quality for a Sustainable Environment. Madison, Wis. Duiker, S. Avoiding Soil Compaction.
University Park: Penn State Extension, Effects of Soil Compaction. Gugino, B. Soil Health Training Manual. Ithaca: Cornell University, Magdoff, F. Building Soils for Better Crops. Beltsville, Md. Russell, E. Miles and M. Santa Cruz: University of California, Lynn Kime. Expertise Agricultural Economics, Sociology, and Education.
Why do we need this? Entering your postal code will help us provide news or event updates for your area. Related Products. Managing Machinery and Equipment Articles. Greenhouse Production Articles.
Guide to Farming: Small Fruits Articles. Loading products Sulfate ions are believed to be adsorbed by these minerals by forming both inner- and outer-sphere complexes. Sulfide S - , S 2- minerals form under reducing environments e. Copper, Zn, and Ni are adsorbed by Fe and Al oxides by forming inner-sphere complexes at low solution concentrations. In alkaline soils, adsorption of Zn on calcite and co-precipitation of Cu in calcite may also occur. Limited evidence suggests that B species i.
Similarly, MoO 4 2- is strongly adsorbed by metal oxides. In certain soil environments, such as those with restricted leaching or those with low-lying areas in arid climates, Cl may exist in precipitated mineral forms, such as NaCl, CaCl 2 , and MgCl 2. Brady, N. The Nature and Properties of Soil, 14th ed. Churchman, J. Alteration, formation, and occurrence of minerals in soils.
Huang, P. Essington, M. Soil and Water Chemistry: an Integrative Approach , 1st ed. Ginder-Vogel, M. The impact of X-ray absorption spectroscopy on understanding soil processes and reaction mechanisms.
Singh, B. Burlington: Elsevier Havlin, J. Klein, C. Manual of mineralogy After James D. Dana , 21st revised ed. New York, NY: Wiley, Lehmann, J. Subsoil retention of organic and inorganic nitrogen in a Brazilian savanna Oxisol. Nieder, R. Fixation and defixation of ammonium in soils: A review. Biology and Fertility of Soils 47, Retention and fixation of ammonium in soils. In Nitrogen in Agricultural Soils , ed.
Stevenson, F. Madison: American Soc Agron, Parikh, S. Soil: The foundation of agriculture. Nature Education Knowledge 3 10 , 2 Rasiah V. Nitrate accumulation under cropping in the Ferrosols of far north Queensland wet tropics. Australian Journal of Soil Research 39, Sparks, D.
Physical chemistry of soil potassium. In Potassium in Agriculture , ed. Munson, R. Environmental Science and Technology 29, Thompson, A. Introduction to the sorption of chemical constituents in soils. Nature Education Knowledge 4 4 , 7 Soil: The Foundation of Agriculture. Sustainable Agriculture. What Are Soils? Food Safety and Food Security. Introduction to the Sorption of Chemical Constituents in Soils. Pests and Pollinators.
Soil erosion controls on biogeochemical cycling of carbon and nitrogen. The Influence of Soils on Human Health. Use and Impact of Bt Maize. Aquaculture: Challenges and Promise. Soil Carbon Storage. Soil Minerals and Plant Nutrition. Soil Water Dynamics. The Conservation of Cultivated Plants. The Soil Biota. Transgenic Animals in Agriculture.
Schulze, Ph. Citation: Singh, B.
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