Understanding Soil

Healthy garden need healthy soil. Plants get water, oxygen, and essential nutrients from the soil. Soil consists of two components: minerals from weathered rocks and organic matter from decayed organisms and animal wastes. Most plants do best in a soil in which half the pore space is filled with air and half with water.

Plants use nutrients obtained from soil to build the cells and tissues needed for growth. Nutrients that plants need in large amounts, called macronutrients, include oxygen, hydrogen, carbon, and an array of minerals. They also need micronutrients, or trace nutrients, which consist of cobalt, chlorine, boron, iron, zinc, molybdenum, nickel, manganese, and copper.

Soil Texture
The size of the individual soil particles, affects how fast water drains and how well plants absorb nutrients. To get the idea about soil texture, take a handful soil and roll in your palms. If feels smooth, and holds the shape for a short time before breaking apart, it's mostly silt. If feels gritty and breaks apart immediately, it is sand. If feel sticky and hold together, it is clay.

Soil Types
Sandy Soil
Coarse-textured soils, contain sands, sandy loamy and loamy sands. Easy to cultivate. Drain well, thats mean the plants do not stand with their roots in water for too long. Since they drain easily, the plants need to be regularly watered, sowing and planting can be done earlier in the year. Sandy soil usually have reddish brown color, easy to dig and feels rough and gritty when handled.

Silty Soil
richer nutrients than sandy soil, can retain moisture. Drain well and much easier to cultivate than clay.

Clay Soil
termed as heavy soils, weighty to lift and difficult to work. Clay soil are acid and bad in drainage. In wet weather become sticky, in dry weather will lose moisture and shrink, will crack in several weeks on try weather. To solve this, add lime, gypsum and more compost.

Loamy Soil
Is medium-textured soil, contain sand, silt and clay in well-balanced proportions. Loamy soils is the most fertile soils. Good for any kind of crop. Warm quickly in spring and rarely dry out in summer. Brown color and crumbly, thats mean easy to dig. Naturally high in nutrient.

Chalk Soil
Fertility is depend on the depth of soil overlaying the chalk bed formation. If topsoil is thin the ground will be poor and hungry. Need more watering and compost than any other soil. If topsoil is thick enough, good conditions are possible. Usually sticky and soft in wet weather, solve this situation by build a good layer of topsoil with more manure and compost. Used green manure.

Peaty Soil
Composed of excessive quantities of humus. Usually very acid, dark brown color, fibrous and spongy texture and not too much nutrients. Warms quickly in spring. Doing drainage and add lime occasionally to correct acidity level. Adding fertilizer will help good condition for plant growth.

Soil Fertility
For checking, soil condition must be moist and warm (55 F), dig up a clod 30 cm square, 15 cm deep on soil that covered by mulch or green manure. Count the earthworms, if more than 10 thats mean you have a good fertile soil.

Soil Testing

• Calcium (Ca): important for cell-wall integrity and root and leaf growth. For alkaline soils (pH > 7) add gypsum (calcium sulphate) For pH >6 use lime. Low calcium will weak the stems and roots, deformed leaves and branches.
  Magnesium (Mg): essential for clorophyll and green leaf. Pale leaves with green veins show your plant got magnesium deficiency. For alkaline soils, add Epsom salts (magnesium sulphate)
• Nitrogen (N): One of the most important mineral, deficiency show by pale yellow leaves and restrict growth. More nitrogen will made soil acidic. Nitrogen can be result from organism activities and nitrogen fertilizer. Hidrogen ion that produce by this process will lock calcium, magnesium and potassium.
• pH: Most plants absorb nutrients best in a soil with a pH between 6.5 and 7.5; however, plants such as rhododendrons require an acidic soil, while others, such as lilacs, grow better in an alkaline soil. Acidic soils are more common in the eastern half of the United States, where rainfall is plentiful, while alkaline soils are more common in the drier west. Use lime to increase pH, and sulphur for decreasing pH.
• Phosphorus: raising and lowering pH to 6.5 will free up phosporus for use. Purple leaves, brittle roots, skinny stems and late fruit and maturity indicate phospor deficiencies. Use super phospahte, rock phosphate as a good resource of phospor.
• Potassium: Vital for stem strength, root growth and disease resistance. Many soils are natually high in potassium. But for sandly and highly weathered soils can be deficient. Yellowing of lower leaves and poor rooth growth is phospor deficienci indication. Use muriate potash, greensand and wood ash as potassium resource.