Basic Needs Of Plants

By Allah Dad Khan Agriculture Adviser To Sohny Dharti TV

Pakistan

CLEAN AIR During photosynthesis, plants take carbon dioxide from the air and use it to produce food for their growth. What is left over after photosynthesis is oxygen, which they put back into the air for us to breathe. Dirty air blocks sunlight, which is also necessary for plants to grow, and may prevent plants from absorbing enough carbon dioxide.

SUNLIGHT Sunlight

Sunlight is used by plants to convert carbon dioxide and water into sugars through photosynthesis. In the absence of sunlight, plants cannot produce the food that they need to thrive. Plants that do not get enough sunlight will have thin, spindly stems that lean toward the light and may wither and die if more light is not received. Plants that receive too much sunlight will grow poorly, as well, becoming bleached or blistered. A plant that requires full sun needs eight to 12 hours of unfiltered sunlight per day, and one that requires partial sun needs from five to six hours. Plants requiring partial shade need indirect or filtered light, and should only receive direct sunlight for short periods of time each day.

WaterLike all living things, plants need water to survive. Water is the conduit for nutrients and food that plants need. The amount of water needed will vary for different types of plants, because some, such as African violets, prefer moist conditions and others, such as cactus and succulents, prefer drier conditions. As a general rule, if the soil feels dry to the touch, plants should be watered.

NUTRIENTsThere are three main nutrients that plants get from soil: nitrogen, phosphorous and potassium. In addition, there are secondary nutrients and micronutrients that are also obtained from the soil plants grow in. The amount of each nutrient required varies with different types of plants, and too much or too little of certain nutrients can stunt growth, produce weak plants or even cause them to die. As plants use the nutrients in the soil, they must be replenished with soil additions or fertilizers, or the nutrient content will eventually be diminished.

SPACE

The amount of space available has a direct bearing on plant growth. Plants with a large area to grow in will extend their roots and thrive. Plants that are crowded or have only a small space in which to grow will have tight, crowded roots, resulting in stunted growth.

WARMTH

In cold climates, few plants can survive, so there is little greenery to be found. Some plants, such as geraniums, require temperatures to be at least 80 degrees F in order to thrive and grow. Other plants can withstand colder temperatures, but very few can survive temperatures that are below freezing. Temperatures should usually be close to that of a plant's native habit to promote the best growing conditions.

PHOTOSYNTHESIS

We humans--and all animals for that matter--must eat food

to supply our bodies with energy. Plants, on the other hand, have the remarkable ability to manufacture their

own food! Plants "harvest" the energy of the sun then use this energy to manufacture sugars. This process is called photosynthesis. In addition to

sunlight, plants need water and air to perform photosynthesis.

They use mineral nutrients, the fourth basic need, to build

the necessary cell structures.

WATER Plants also need water for things besides photosynthesis.

They need water to maintain cell pressure--pressure within the plant's cells is what keeps stems sturdy and leaves opened to the sunlight. But plants lose lots of water during a process called transpiration, during which water vapor escapes from pores on the undersides of the leaves. Why should gardeners care about transpiration?

Because one of the most important factors in growing healthy plants is maintaining proper moisture levels. The rate at which a plant is transpiring has a huge effect on how much water it needs!

The warmer, drier, windier, and sunnier it is, the more water a plant loses to transpiration. During dry weather, you

need to replace this lost water, or plants will wilt.

WATERINGVegetable plants need plenty of water throughout the entire

growing season. Apply 1 to 1 ½ inches per week in a single watering,

unless rain does it for you. Light sprinklings may do more harm than good because roots tend to form near the surface of the ground if water doesn’t penetrate deeper. Shallowly rooted plants are more Susceptible to drought damage. Sandy soil requires more frequent watering than heavy clay. However, always apply water slowly so it can soak in. Check the amount applied by catching it in straight-sided tin cans placed throughout the garden, or by digging down to see if the moisture has penetrated at least 6 inches. Inexpensive plastic rain gauges are also available

WHAT TYPE OF SOIL DO YOU HAVE?

You've probably heard that the ideal garden soil is a rich loam.

But what exactly is this? A rich, loamy soil contains a range of mineral particle sizes

——from microscopic clays to relatively large grains of sand. These particles are bound together into groupings of various sizes called aggregates. Soil composed of these aggregates

has lots of pore spaces of various sizes, and these spaces contain

water and air. If all the spaces contain water, the soil is waterlogged; few

plants can withstand such saturated soils for long, because plant roots

need air.

SOIL TEST: A soil test is the only way to know what nutrients your plants need. Your soil test results tell you how

much and what type of fertilizer your plants need, tells you

the soil pH--how acidic or alkaline your soil is . Also tells about micronutrients and lead. Soil test Results depend on how well you take the soil sample. The sample should reflect the overall lawn or garden condition. Make a representative sample by collecting Small amounts of soil from various spots within the

target area.

SOILChoose the spot in your yard that has the best soil. You may be able to distinguish the quality of your soil by looking at your lawn. If it looks lush and healthy, then the soil supporting it is probably good for a garden. Don't pick the spot where the lawn is the worst, and figure you can

get out of reseeding by locating your garden there.

And avoid low spots that stay wet in the spring.