How does soil help plants grow

What will it tell us? Constants: Punch cup, soybean plant, access to light, air quality, temperature Variables: Substrates, nutrients, water Discuss with students what they hypothesize will happen.

How will each of the plants fare? Why do they think that? Have students journal their hypotheses overall and with each individual plant in their science journal. Tell them to hypothesize reasons for their guesses as best as they can, as well. Five to seven days after the seedlings are planted, have the class re-analyze how each plant fared. What do they notice?

Before discussing as a whole group, allow students to walk up to each plant, analyze, and take notes in their science journal.

Again, have them make observations overall, and for each specific plant. Prompt them to look for changes in color, shape of plant, texture, etc. After each student has made observations, bring the group back together for a class discussion. How do the plants look? The Control plant is likely dead, as may be the plants in only water.

This is because roots need water and air to survive. The plants without nutrients likely did worse than those with extra nutrients. Can students tell a difference between plants in soil with nutrients and without?

Discuss the potential issues with using too many nutrients toxicity to plant, loss to environment, additional cost. Discuss with students what they can glean from the experiment overall. They can see that plants growing in a solid substrate like soil have support to stand tall. Plants with nutrients and the correct amount of water and air grow better.

But why do plants need nutrients? Plants do photosynthesize, but they need more types of nutrients to survive. When plants photosynthesize, they make glucose C6H12O6. Then, the glucose is transformed into ATP via cellular respiration. ATP stands for adenosine triphosphate, which includes nitrogen and phosphorus in addition to carbon, hydrogen, and oxygen. The plant needs these nutrients to grow and create plant matter but cannot get them from the air or water.

The plant must absorb these nutrients via its roots. Introduce students to the idea of essential nutrients. There are 17 nutrients essential for plant growth. Some of these are micronutrients. Some are macronutrients.

This essentially means that some are needed in small amounts and others are needed in large amounts. Nitrogen and phosphorus found in ATP are macronutrients and are needed in large amounts. Farmers generally pay attention to nitrogen, phosphorus, and potassium as fertilizers in their field to maintain plant growth.

Review with the class why the plants look the way they do. What does soil provide for plants? Why does that matter?

It provides a substrate that supports the plants, and provides nutrients, air, and water, through a network of pore spaces, minerals, and a realm of living and organic material. Have students write some wrap-up notes either accepting or declining their original hypotheses about what happened to the plants. Activity: Exploring root structures This activity will encourage students to explore root structures and observe differences in plants.

Start class with a dissection activity. Have full-grown potted plants a variety of plant types would be ideal — have them labeled for identification for small groups of students students per group. Australian Journal of Soil Research 29 6 - Published: Soil, land care and environmental research.

Shopping Cart: empty. This zone is different from the rest of the soil, and it sometimes supports specific and unique organisms. Similarly, some nitrogen-fixing bacteria grow together with some plants, including many legumes members of the bean family. The bacteria convert atmospheric nitrogen into forms that can be used by their host plants.

When the host plant dies, the nitrogen compounds released during decomposition are available to the next crop. Any mutually beneficial relationship between two dissimilar organisms is called a symbiosis. Water is an amazing substance.

It is called the universal solvent because it dissolves more substances than any other liquid. It is a renewable natural resource. It exists in nature as a solid, liquid and gas. Its molecules cohere stick together and adhere stick to to other surfaces; this accounts for its ability to reach the top of tall trees.

It has a high latent heat, which means that it releases a large burst of energy when it passes from solid to liquid and from liquid to gas. And, when it passes from gas to liquid and from liquid to solid, it absorbs a large burst of energy.

Gardeners reap the benefits all of these attributes of water. Clayey soils have high water-holding capacity, while sandy soils have low water-holding capacity. Clayey soils drain much more slowly than sandy soils. Loamy soils reach their field capacity days after a heavy rainfall or irrigation. If no more water is added, the soil continues to dry out; plants take up some of the water, and some water moves upward in the soil and evaporates from the surface.

Eventually, a soil may dry enough to reach its permanent wilting percentage , the point at which a plant wilts so severely that it cannot recover. At this point, the available water water that remains available to the plant is gone, and the only water that remains in the soil is so tightly bound to soil particles that plants cannot access it.

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. You can raise soil pH by adding calcium carbonate and lower pH by adding sulfur to the soil. The amounts of available nutrients vary by a soil's pH level. Based in Indiana, Molly Allman holds a B. She works as both a writer and author and enjoys writing articles on many different topics.

She specializes in topics concerning health, crafts, family and lifestyles. What in Soil Helps Flowers Grow? Home Guides Garden Garden Care. By Molly Allman. Related Articles.