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Research and development in science and biotechnology have brought new approaches to farming that can withstand with polluting soils and changing lifestyles. New approaches for farming based on urban living has grown up. 

HYDROPONICS


The practice of growing plants in nutrient-enriched water (without soil) is called hydroponics. Because photosynthesis is the chief principle mechanism running behind in plants, and all that is needed for photosynthesis is sunlight, carbon dioxide, and nutrient supply through roots. 

In nature, plants uptake water and nutrients from the soil by the well-established deep root system. They depend on sunlight for photosynthesis and rely on atmospheric carbon dioxide for driving out the process of transforming light energy into chemical energy. 

In hydroponics plants are grown in water and roots have direct access to nutrients, so they do not have to grow longer and much of energy is diverted to the growth of leaves and aerial parts. 

With smaller roots and no need for farmland, hydroponics farm can be set in a greenhouse or even a balcony in concrete jungles also. 

Requirements for a hydroponic farm

All that is needed in hydroponics are a bunch of plastic troughs, pipes into which water enriched with nutrients are supplied and plants are grown in them. Greenhouse having the artificial light facility, pH monitoring devices, humidity measuring devices are all other accessory devices needed. Because the plants are grown on an entirely artificial setup, growers need to take extra care about plants. 

The root system is not well protruded and since the plants float in continuously circulated water, plants bearing larger aerial parts are not a better choice for hydroponics. Few growers use media like vermiculite, peat, Rockwool for supporting the root system. For plants bearing fruits special supporters may be installed at the time of setting up of hydroponics farm. 

Fast-growing plants like tomatoes, strawberries, lettuce, oregano, cilantro, spinach, basil, parsley and bell peppers produce greater results for farmers in hydroponics. Having a short life cycle and comfortable size ratio of aerial to root parts make them good returning species in hydroponics farms. 

Variants in hydroponics 

The main principle of hydroponics is that roots grow in water without a soil substratum. 

Basing on the size and purpose of the farm, water flow may be either static or continuous. 

Static water cultivation is the simplest one where water is maintained at a required level in troughs and roots are allowed to fall into it. Small scale farms have floating valves to adjust the water levels. This system needs a water reservoir to be covered with black plastic or aluminium foil to avoid exposure to sunlight. Sunlight induces the growth of alga in static water systems and this is a point of concern in hydroponics. 

Continuous flow hydroponics are those where nutrient solution flows continuously in the chamber containing suspended roots. A large tank containing nutrient solution is set at the bottom or one corner of the farm and nutrient solution is continuously pumped and allowed to flow through tubes. 

This set up needs expertise during construction and demands certain slopes in the channel for the easy and complete flow of nutrient solution.Proper channel slope along with enough channel length and right flow rate are design features in continuous flow hydroponics. 

Easy and random sampling (to check the pH or nutrient content) from any part of the farm is a main additional task for growers in continuous flow technique. This step ensures the proper distribution of nutrients along the length of flow channels. 

The level of the nutrient solution can be easily lowered when roots require aeration (to prevent waterlogging) in this system with the help of its accurate design. 

Subsets 

Keeping the hydroponics principle as main criteria two different subsets are in practice. Aeroponics and aquaponics are two variants of hydroponics.The basic principle lies the same. 

Aeroponics is a technique of growing plants with their roots placed in an environment saturated with nutrient solution. The plants are grown with efficient support systems having roots suspended in a nutrient solution saturated airtight chambers. There are spray jets for spraying a fine mist of nutrient solution periodically into the chamber containing roots. 

The only problem in hydroponics is that roots are waterlogged and suffer from suffocation, which is solved in aeroponics. The roots here face a cent percent oxygen availability. But the problem lies here itself. 

The aerosol maker otherwise called mister should be monitored periodically. The quantity of nutrient solution sprayed is largely dependent on the aerosol sprayer. If not, the roots will dry out and plants die. 

Aquaponics refers to raising fish and growing plants, both on the same farm within a closed-loop system. It is a sustainable farming technique where fish are grown in the circulating waters of hydroponics culture. 

These fish provide natural fertilizer for the plants that are broken down into simpler nutrients easily absorbable by the plant roots. Plants purify the water by absorbing dissolved nutrients in the water where the fish are growing. 

A small-scale farm for supplying vegetable needs for the family or local community is beneficial. Aquaponics farm on commercial-scale needs extra care concerning the maintenance of the tank. Checking the pH of water with stipulated intervals and physical observance on plant quality as well as fish is needed for proper maintenance of the commercial farm. 

Any stress faced by either of them can have an obvious impact on the life and quality of others. However, aquaponics is a better choice in terrestrial areas where people depend on imports for fish. Fresh fish devoid of fertilizers and chemicals are always a hot cake in the urban world. 

Problems faced by growers 

Hydroponics farms lie in a closed environment and plants rely on artificial light and humidity. The water input and nutrient content are all to be monitored. This is where the growers are caught with problems. 

Proper scientific knowledge and maintaining the balance of nutrients at different stages of the growth cycle of plants is needed. 

Hydroponic nutrient solutions are generally highly concentrated and water-soluble solutions that are dissolved in the right amount of water basing on tank size of the farm area. A disturbance in the balance of nutrients during various phases of growth cycles can lead to low productivity and also the death of cultivating plants. Both of them can swipe away the financial gains of farmers. 

Advantages 

Since hydroponics does not demand any specific crop area and do not need land restoration for setting up the farm, hydroponics is adapted even in urban areas by modern farmers. 

Because the plants are in no contact with soil and soil is a prime harbor for pathogens, hydroponic crops are pathogen-free. Hydroponic farms are in closed environments so the plants are pest-free. That too the plants are under continuous monitoring of pH and humidity. So, the growers are ensured with a handsome amount of financial gains in return for their investments. 

With its independence on natural sunlight and soil (since large of agricultural land lost fertility) hydroponics stands as one of the modern serves of current food needs. 

Hydroponics is operated in a closed environment and humidity is under strict control. It is dependent on artificial light and hence nutrient water used in hydroponics is less subjected to evaporation. Water loss due to evaporation is very less or negligible. Where, the word “Farming” poses some expectations of large water needs, hydroponics is something different. 

FARMING IN GREENHOUSES 


With changes in climatic conditions, switching to modern farming methods has become one good option for farmers. Rather than depending on the natural environment, greenhouses are one good approach for growers of vegetables, fruits and horticulture. 

Global warming is the burning problem now and has a combo effect. Changes in rainfall patterns, sunlight, raising temperatures, climate extremes are all outcomes of global warming. 

Agriculture depends on the existing environment and so erratic patterns in any of the climatic factors pose a serious issue to the output. Farmers adapt to modern techniques like farming in greenhouses or polyhouses. 

Greenhouses are the framed structures of transparent material over a large growing area. All conditions are controlled either partially or completely and monitored well.The main agenda is to maintain optimal growth conditions for plants rather than depending on the natural climatic factors. 

Polyhouses and greenhouses are almost the same with only a minute difference that Polyhouses have transparent polythene sheets as shelter while term greenhouses refer to those having either polythene sheets or transparent glass. 

Setting up a greenhouse 

Before a farmer starts cultivating in the greenhouse, a perfect plan for greenhouse set up is made. The place for greenhouse cultivation needs to be selected. And then the perfect design is selected based on the commodity being produced, that is either if the farmer is interested in producing vegetable crops or floriculture. The land is selected after the pH is checked and ensured with proper irrigation set up and drainage for leaving excess water. 

Setting up a greenhouse is a cost-effective process and hence farmers stand selective in crop to be cultivated. Greenhouses provide ambient conditions for growing small-sized herbs that can bear aerial products which are the final products for the market. It can be either vegetable or fruit crops like tomatoes, cucumbers, strawberries, bell peppers, and most cut flowers for floriculture gains. 

Maintaining internal conditions 

Greenhouses can be either partially artificial or completely artificial basing on infrastructure set up during construction. 

Vents are set up for aeration supply to maintain rich amounts of carbon dioxide and oxygen levels. Carbon dioxide is much needed for the growth of plants as it drives the photosynthesis which is much needed for growth. 

Vents may be used or sometimes artificial air supplies are used. This is basing on prevailing climatic conditions and phases of the crop for growing needs. 

Natural ventilation is set up with nets and ridges.Wind direction prevailing in the area is a prime factor to be concerned during the construction of naturally ventilated greenhouses. 

Ridges are planned and set up so that more natural wind can enter the farm. This lowers the dependence of farmers on artificial aeration set up and thus can lower the cost of farm maintenance. 

Mechanical ventilation is set using fans and cool pad fans. Mixing fansare set up for large farms. 

Artificial lights are the best choice for light to drive out photosynthesis in a long day favoring plants. They stand as the only option for daylight in low sunlight regions of the globe.Paraffin lamps can increase carbon dioxide levels in the greenhouse apart from providing light to drive photosynthesis on. 

Depleted carbon dioxide levels can hamper the growth of plants. So, an eye watch on levels of carbon dioxide is much needed. Few farms have carbon dioxide generators that depend on natural fuels which work in two ways. One that they produce carbon dioxide by burning and second that they raise the internal temperature in chilling nights. 

Shade controls like nets and shade screens are installed during construction itself. They help to reduce the length of daylight and also in reducing light intensity in hot summers where high daylight intensity harms the photosynthetic apparatus. 

This way they provide ambient conditions for short day favoring plants. These set up help in mimicking seasons and in producing unseasonal crops. 

High invested farms are availed with air conditioners for providing chilling temperatures for high-value crops. Natural fog is mimicked with over-head misting devices for extended winter-loving crops. 

Advantages 

Certain regions on globe face climate extremes like frosts, low daylight, extremes harsh temperatures, limited water supplies with arid temperatures, etc. Though the soil can support the growth of plants to some extent depending on naturally prevailing climatic factors brings bad fate to plants. Greenhouses are a better option for cropping in such areas. 

Because farming on fertile lands having ambient climatic conditions is becoming a problem nowadays, greenhouses can bring about a rise in farming lands in the current scenario. 

Utilizing whatever possible farm area with some human intervention can help to serve the existing and growing global food needs to some extent. 

Growing crops in a closed, controlled environment prevent their exposure from climatic extremes like chilling, frosting, drought, high-intensity sunlight, precipitation, scorching temperatures, insects and diseases. 

Since it has availability in monitoring and controlling the internal conditions within a greenhouse, farmers gain an opportunity of cultivating both seasonal and un-seasonal crops basing on the market demands. 

Year-round cultivation to satisfy floriculture and rest market demands is possible in greenhouse cultivation. Artificial lighting facility avails farmers to mimic the extended daylight for flowering phases in many floriculture farms. Chrysanthemum, Roses, Anthurium, Gladiolus are all popular cut flowers cultivated in greenhouses.

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