Abiotic Factors and Effect on Plants

Plant growth is affected by both abiotic and biotic factors. Abiotic factors are non living; they can be physical or chemical. Without both biotic and abiotic factors, there cannot be any plant growth.

Abiotic factors nourish and sustain plants. They are the substrate or raw material on which the biotic materials work. Abiotic factors can also influence the kind of microorganisms present in the soil.

They can restrict the function of some microorganisms. For instance, it is very difficult to use fungi to control the number of nematodes in the soil because of the competition the fungi will face from other microorganisms.

What are Abiotic Factors?

There are a number of abiotic factors like pH, topography, sunlight, soil, salinity, temperature, latitude, weather, clouds, oxygen, air, water and more. We will discuss some of them below.

Soil: Soil includes factors such as soil air, pH, texture and more. The texture of soil varies from sandy to clay. Soil air occupies the space between soil particles. Soil pH affects biological activity and mineral availability in the soil.

Light: Light kicks off photosynthesis. The quality of light, its length and intensity play an important role in plant growth. Did you know some plants flower only at certain times? Depending on light intensity, some plants are called short day plants, day neutral plants and long day plants.

Temperature: Temperature affects the distribution of plants. In a desert, you will find different kinds of plants, compared to a rain forest. Basically, different plants have evolved to survive in different conditions. Temperature is also important for other processes, like flowering of plants.

Water: There are three types of plants. Hydrophytes are adapted to a watery environment (like water lilies). Mesophytes are adapted to conditions of neither too much water nor too little water (like rose, peas). Xerophytes are adapted to water deficient conditions (like cactus).

Wind: Wind contains humidity or water vapor. When this water vapor condenses, it falls in the form of snow, hail or rain. Wind also helps in the dispersal of seeds and pollen. Wind erosion causes destruction of top soil.

Topography: Topography includes slope, water bodies, terrain and land elevation. Topography is important for site and crop selection. For instance, tea is not grown below 1000 meters to sea level. The topography of a place also affects other abiotic factors in that area.

Climate: Any long term weather phenomenon that sustains for 30 years or more is the climate of that region. Climate is one of the most important abiotic factors to affect plant growth. For example, precipitation and temperature in an area determine the climate of that place. The climate of a grassland ecosystem is hot and dry during spring, and cold during winter.

Influence of Abiotic Factors in Organic Farming

Organic farming pays special attention to abiotic factors. Here are some reasons why:

  • Agricultural pollution (excessive addition of fertilizers, pesticides, weedicides) and intensive farming is degrading our water and soil. Moreover, monoculture destroys the ecosystem by modifying the landscape.
  • Current approaches like organic farming, integrated pest management, conservation tillage, and integrated plant nutrition create advantages in terms of more nutritious food, better farming practices and better soil health.
  • Organic farmers like us are aware of the repercussions of overloading the soil with fertilizers and other chemicals. The food grown in such soils are often deficient in nutrients.
  • When food is lacking nutrients, we are forced to eat more food to get the same amount of nutrients as earlier, leading to calorie overload and conditions like obesity. To counter this, we produce our own soil to grow our vegetables.

To know more about the perfect abiotic conditions for plant growth, please contact us.

Five Breakthrough Developments in Organic Farming

Last year, there were numerous studies on the human health and environmental benefits of organic farming. Organic farmers can now take strength from these empirical studies to bolster their pro organic position.

These studies spoke about how organic food can help us reduce our exposure to pesticides, sustain water quality and even mitigate the effects of climate change. Here are four breakthrough developments in organic farming in 2015.

Organic farming can improve soil: A research article published in Agronomy for Sustainable Development says that organic farming is advantageous for soil organisms. The study is the culmination of 14 years of research. The study found the population of larger soil creatures in organic soil is up to 250 times larger than that in conventional soil. The microorganism count in organic soil is also up to 70 percent higher. Another study printed in the Sustainable Agricultural Research journal found that organic soil management improves soil structure and nutrient availability.

Organic farming sustains water quality: Researchers who analyzed nitrogen runoffs from farmlands found that farmland where crops are grown organically suffers from less nitrogen pollution, compared to farmland where crops are grown conventionally. In another study, it was found that organic farming can bring down water pollution in U.S waterways. The study found that nitrate loss through water from a conventional farmland is twice the rate of nitrate loss from farmland where food is grown organically.

Organic farming can help mitigate climate change: Did you know agriculture is responsible for 35 percent of the global green house gases produced each year? Organic farming can help us reduce the emission of greenhouse gases. An article in Science Bulletin magazine says organic farming can help us sequester carbon in the soil, preventing its emission into the atmosphere, eventually reducing the green house effect. Feeding crop residue to animals as fodder and using organic manure instead of chemical fertilizers can also help curtail green house gas emissions, while increasing carbon storage in the soil.

Organic farming can give higher yields than conventional farming: It is a myth that organic farming gives a lower output than conventional farming. We know that this is false from our experience in organic farming. A study published in the Renewable Agriculture and Food Systems magazine produced by the Cambridge University Press says that the output from organic farming can be equivalent to the output from conventional farming.

The same study also says organic farming can reduce weeds in a soil by up to 47 percent and nitrogen content by 7 percent. Another study that collated and synthesized information from over 100 studies and in excess of 1000 field observations showed that organic farming can deliver higher yields than previously thought.

Eating organic food reduces pesticide exposure: One major study found that you can cut your exposure to pesticides, drastically, with organic food. Pesticides are dangerous and their ingestion even in small amounts has devastating effects on the body. For instance, endosulfan which was a common pesticide some years back is known to cause birth defects in unborn children. It is also an abortifacient.

Another study showed a relation between respiratory symptoms in children and organophosphate pesticides. Did you know children who are exposed to pesticides have a lower mental ability than children who are not? In another study, it was found that pesticides can increase the risk of having a child with ADHD. Pregnant women exposed to pesticides have a higher chance of giving birth to children who will suffer from ADHD syndrome.

The gist is, choosing organic food over other types of food can create a healthier world.

Insect Pests in Organic Farming: How to Biologically Control Them

Insects are highly mobile, and they are well-adapted to crop production and pest control. As such, insect management is a challenge to all farmers, and not just organic farmers. In traditional farming, insect management focuses on eliminating insects. But organic farming does not try to eliminate insects; it seeks to manage them.

Three Components of an Insect Management Plan

A well-designed insect management plan contains three components: biological information, ecological information, and behavioral information.

Biological: What does the insect need to live? Once you’ve determined it, deprive it of this resource.

Ecological: How does the insect interact with its environment? Use this information to create a pest resistant environment.

Behavioral: How does the insect behave? Use this information to manipulate the insect’s environment.

A well-designed insect management plan will include elements of all these factors. There is no single tactic that will help you suppress insects.

Insect Management Strategies for Organic Farmers

Organic farmers must first understand what kinds of pests and beneficial insects thrive in a particular crop. It will help them anticipate the problems likely to occur in that crop. An experienced organic farmer knows that pests are most effectively controlled when their population is low.

Cultural and biological controls are effective at controlling insects. Crop rotation can also prevent the build-up of insect populations. Growing the same crop, on the same land, year after year is an open invitation to insects. Below you will find some additional pest management strategies that can be used on farms.

Keep track of pests: It is very important to identify pests and beneficials on a crop. Beneficials means good insects from a farmer’s point of view (i.e., ladybugs). You must learn to identify the eggs, nymphs, and larvae. Look for descriptions of insects in pest control manuals released by various agricultural universities.

Pheromone traps can also help with some pests. Pheromone traps confuse the males, and prevent them from mating. This ultimately reduces the next generation of pests and the resulting feeding damage. At the same time, you must keep a look out for biological controls that affect pests. Most farmers don’t realize that beneficial insects and microorganisms are also working concurrently to control pests. As a result, they end up treating the plants when it is not needed.

Time planting and harvesting dates: Did you know you can outsmart some pests by timing the planting and harvesting of your vegetables?

Take cabbage for example. You will want to plant cabbage quick to mature cabbage varieties, and harvest them by late spring or at the latest, early summer. Come summer, you will have to contend with the cabbage looper (a type of pest). You should plant the seeds indoors, and move them to raised beds when they are 7 or 8 weeks old.

Provide optimum growing conditions: Try to grow your vegetables in optimum conditions. Most plants can withstand feeding by insects if they are growing actively and are able to compensate for loss of root tissue and foliage. Too little water makes some plants vulnerable to pests (like spider mites).

Covering crops planted and harvested before planting the main crop can also improve the fertility of the crop. There is also something called a trap crop. These crops attract pests, and keep them away from the main crop. An example of a trap crop is Alfalfa.

Tillage can destroy pests: Soil tillage can kill pests by exposing them to predators, like birds and wasps. Tilling also increases the rate at which plant residues breakdown. These plant residues harbor pathogens and insects.

Allow the organic matter to decompose fully before you plant your crop. Keeping the field fallow for a period after harvesting a crop can also help. It can help you control pests like root maggots, cut worms, and bulb mites.

Using beneficials to control plant pests: Some plants are home to beneficial organisms which prey on the pests that target these crops. If it were not for these beneficials, pests would take over most crops.

There are companies that supply beneficials. Just make sure that the beneficial that you are going to introduce is suited to your climate, and it is the correct species. You have to release multiple batches of a beneficial to reduce the level of pests to a management level. Some common beneficials are ladybugs, hoverflies, lacewings, and wasp parasites.

Using chemical controls to manage pests: There are many organic insecticides which can prevent pests from proliferating. Before you select an insecticide, there are a few factors that need to be considered. You should ensure that the insecticide is not toxic to humans, verify that it will not affect the beneficials, and recognize that the mode of delivery is important.

Some pests breed on the underside of the leaves. The insecticide must be able to reach the pests under the leaves. Azadirachta indica (also called Neem) is an excellent organic insecticide. Tobacco spray, orange citrus, garlic, and onion spray are other organic insecticides.