Hilling, earthing up or ridging is the technique in agriculture

Agriculture

Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

 and horticulture

Horticulture

Horticulture is the industry and science of plant cultivation including the process of preparing soil for the planting of seeds, tubers, or cuttings. Horticulturists work and conduct research in the disciplines of plant propagation and cultivation, crop production, plant breeding and genetic...

 of piling soil

Soil

Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

 up around the base of a plant. It can be done by hand (usually using a hoe

Hoe (tool)

A hoe is an ancient and versatile agricultural tool used to move small amounts of soil. Common goals include weed control by agitating the surface of the soil around plants, piling soil around the base of plants , creating narrow furrows and shallow trenches for planting seeds and bulbs, to chop...

), or with powered machinery, typically a tractor

Tractor

A tractor is a vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction...

 attachment.

Hilling buries the normally above-ground part of the plant, promoting desired growth. This may either encourage the development of additional tuber

Tuber

Tubers are various types of modified plant structures that are enlarged to store nutrients. They are used by plants to survive the winter or dry months and provide energy and nutrients for regrowth during the next growing season and they are a means of asexual reproduction...

s (as with potato

Potato

The potato is a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family . The word potato may refer to the plant itself as well as the edible tuber. In the region of the Andes, there are some other closely related cultivated potato species...

es), force the plant to grow longer stems (leek

Leek

The leek, Allium ampeloprasum var. porrum , also sometimes known as Allium porrum, is a vegetable which belongs, along with the onion and garlic, to family Amaryllidaceae, subfamily Allioideae...

s), or for some crops (chicory

Chicory

Common chicory, Cichorium intybus, is a somewhat woody, perennial herbaceous plant usually with bright blue flowers, rarely white or pink. Various varieties are cultivated for salad leaves, chicons , or for roots , which are baked, ground, and used as a coffee substitute and additive. It is also...

, leeks etc) this blanching technique keeps the stems or shoots pale and tender, or influences their taste.

Hilling may also be used to stabilize the stems of crops which are easily disturbed by wind.

Example

A common application of hilling is for potatoes. The tubers grow just below the surface, and can produce chlorophyll

Chlorophyll

Chlorophyll is a green pigment found in almost all plants, algae, and cyanobacteria. Its name is derived from the Greek words χλωρος, chloros and φύλλον, phyllon . Chlorophyll is an extremely important biomolecule, critical in photosynthesis, which allows plants to obtain energy from light...

 and solanine

Solanine

Solanine is a glycoalkaloid poison found in species of the nightshade family , such as the potato . It can occur naturally in any part of the plant, including the leaves, fruit, and tubers. Solanine has fungicidal and pesticidal properties, and it is one of the plant's natural defenses...

 if exposed to light (green potatoes). Solanine is toxic in large doses, and can result in nausea

Nausea

Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

, headache

Headache

A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...

, and in rare cases, death

Death

Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....

. By hilling one or more times during the growing season

Growing season

In botany, horticulture, and agriculture the growing season is the period of each year when native plants and ornamental plants grow; and when crops can be grown....

 – effectively, burying the potatoes in an additional few inches of soil – yield

Crop yield

In agriculture, crop yield is not only a measure of the yield of cereal per unit area of land under cultivation, yield is also the seed generation of the plant itself...

 is improved, and the harvest

Harvest

Harvest is the process of gathering mature crops from the fields. Reaping is the cutting of grain or pulse for harvest, typically using a scythe, sickle, or reaper...

 remains edible.

External links

• How To Grow Potatoes : How to Hill Potatoes YouTube
  YouTube
  YouTube is a video-sharing website, created by three former PayPal employees in February 2005, on which users can upload, view and share videos....
  
  
• Timing of herbicide application and potato hilling American Journal of Potato Research