Saturday, January 31, 2009

Substrates used in Hydroponic systems

Substrates that can be used in simple Hydroponic systems

For people who generally live in rural areas, finding substrates like rice husk, or coconut peat is not a problem.

Rice Husk:
  • is an excellent substrate which has one of the best drainage.
  • since there is no compaction even after watering, it provides good aeration for the development of roots.
  • The rice husk must be thoroughly washed in clean water as it might contain inert materials like sand, stones , insect eggs etc
  • sun drying after washing is done for a period of 2 to 4 days.
  • weed seeds sometime can get mixed along with the rice husk, so trials can be conducted to see if the rice husk substrate has any weed seeds in them. Soaking the husk in water & allowing to dry for a few days generally is the best method.
  • In rice mills, burnt husk is also available. This is better as the chances of weed seeds, insect eggs etc are eliminated
Coconut peat
The numerous advantages of coconut peat can be seen in my early posts. Or you can view them again by clicking here

Washing the substrates:
before using either rice husk or coconut peat, they have to thoroughly rinsed in clean water

The most common problem found in coconut peat is it contains a lot of inert material, sand, soil & even insects. so it has to be washed several times , in clean water and sun dried for a couple of days before using it.

The photo below shows the residual sand/soil that i collected after washing 3 kg of coconut peat

This is mostly fine sand and soil particles, & this is detrimental to the dev. of roots. the presence of soil, results in compaction & formation of clay which will result in poor drainage, water logging & poor aeration. The coconut peat can also be filtered using fine filter net, before washing to remove the bigger particles

The heavier sand/soil particles can be found at the bottom of the container & the lighter coconut peat floats at the top.

the sun dried coconut peat can be used after 2 to 4 days.

Photos and content by Pritham 'Heavy metal farmer' denzil dsouza

Build your own germinating tray/tub for hydroponic cultivation

simple methods to start with your very won Hydroponic garden in your own backyard, roof top terrace or front porch

a simple plastic tray, preferably inexpensive, can be used as shown in the figure

next, a drain hole must be drilled into the plastic container. an electric drill can do the trick. even a piece of iron rod, heated to high temperature using a candle could do the trick of drilling a hole of desired size. the hole must be drilled at 1 inch from below the bottom of the tub as shown in the figure

a tank joint (15 mm dimension) must be used which acts as a drain tube, must be fixed as shown
the tub must be filled with suitable substrate. for this post, i have used rice husk. The rice husk has excellent drainage features & acts as a good substrate if one wishes to grow root vegetables.

Important Note
drainage is the key in any successful Hydroponic system. since most of the times, water which is rich in nutrients is added (fertigation) and so the water must not be allowed to go waste.
a little slope is also helpful in draining the trays of excess water, as it might start to rot the organic substrate and even the roots. fungal problems arise due to bad drainage.
the excess drained water is collected in collection containers suspended from the drain pipes as shown in the figure below.

once a week, clean water is added to the trays to 'flush out' the substrate of any harmful residues.

Photos and content by Pritham 'Heavy metal farmer' denzil dsouza

Thursday, January 29, 2009

Some Tips For Amaranthus

Tips & Precautions while growing Amaranthus(harive soppu)

amaranthus ready for harvest

uniform germination

watering with too much force results in patches in the beds as seen above

  • the seeds must be mixed in a 1:2 or 1:3 ratio with sand. since the seeds are small, mixing with filler material is done and then broadcast
  • the growing beds must be of even shape & dimensions. an ideal bed will be 6 to 10 inches raised height
  • the height is raised as continuous watering will result in soil compaction & rooting is affected greatly. even harvesting will be affected as the plants break off at the ground level.
  • watering must be done with watering can, or hose pipe if a large area is covered & with less intensity. if watering is done with force, the seeds will be displaced from the raised beds. also a lot of water can be conserved by light irrigation
  • the seeds will germinate in 3 days & the beds will see uniform growth on 7th day. if by the 4th day, there is no uniform germination, seeds must be again broadcast immediately.
  • mixing the seeds with turmeric powder is also done and then broadcast to prevent seeds getting destroyed by ants
  • it is important to maintain a chart to keep tab of the harvest cycle. seed beds should be made & seeds broadcast every 5th day to maintain a uniform harvest cycle.
  • when conditions are favorable, harvesting can be done every 21 days & the older beds can be worked upon & seeds sowed after adding manure/compost

Photos and content by Pritham 'Heavy metal farmer' denzil dsouza

Seed Production in Amaranthus

Following are the methods adopted for seed production of Amaranthus also called harive soppu and bhaji.

  • healthy plants with good inflorescence must be selected.
  • diseased, infested by insects , weak plants are not selected as the seeds obtained from them will be of poor quality
  • care should be taken to see that weed plants are not harvested along with main plants
  • all the unwanted leaves, branches, stem etc are trimmed & only the inflorescence is sun dried for a period of 7 to 15 days
  • white or transparent plastic sheet must be used and the inflorescence must be spread out evenly on the surface
  • drying process is complete when there is total discoloration of the plant. it changes from green to burnt yellow/brown color.

Packing and storage
  • once the plant is completely dried, the seeds can be separated by threshing or beating the plant on a wooden plank or rough surface. even rubbing the inflorescence against each other dislodges the seeds
  • the seeds are very small in size & black in color & round in shape.
  • the seeds thus obtained must be kept in air tight containers & stored in a dry place.

Precautions and tips
  • since there are 2 distinct color types, one green the other maroon, seeds of the required color plants can be obtained by not mixing the 2 while threshing, separate the green plants from the maroon plants
  • do not keep in containers that are defective or have cracks as even a little moisture in these containers will encourage the growth of fungus & will damage the seeds
  • ants & other insects can also be a problem if the storage containers are not proper. to control ants, 3 or 6 pieces of cloves can be added in the containers.
  • certain chemicals like Thiram can be used for longer storage to prevent attack from insects
  • the area of storage must be in a dry place, well aerated to prevent any kind of fungal attack.
  • after using the seeds, the container must be closed properly,
  • always use clean hands while handling seeds. after using any chemicals, wash hands with clean water thoroughly before handling seeds

    Photos and content by Pritham 'Heavy metal farmer' denzil dsouza