Bio
intensive Raised Bed farming : Natural
ResourceManagement
& Soil Health Care – An organic
farmer’s experiences .
Farmer Samir R Bordoloi
Freelance Organic Farming Expert
.
Facebook page : Grow your own
food with Farmer Samir .
Mobile No : 08486029583
The growing human
population which is above 1.8 per cent per year is a big concern for the
humanity to address the problem of food availability for such a great
population with limited resources. This problem is leading to make agriculture
very intensive and a big pressure is put on the scarce natural resources. The
most vulnerable victim of such a situation is the Soil which has to take all
the negative effects of tillage operations and the chemical fertilizers and
pesticides. As soil belongs to our future generation and we have borrowed from
our sons and daughters we have to return it safely and in a good conditions. In
sustainable agriculture , the main focus is on the soil. As if the soil dies ,
the farmer also dies . One of the major reasons of numerous farmer suicides in
the country is the degradation of the soil health unable to give better
production of the crops and pushing the farmer to the burden of debts.
The maintenance of
a living healthy soil of the farm leads to production of good healthy food. Bio
intensive way of food raising is a good way to ensure better soil fertility for
a long time. Bio intensive way of food production depends on a deeply prepared
garden bed whose growing area , with high density planting , can produce up to
four times more food than an same size of shallow bed planted in rows. This
type of beds require less work with only one bed to dig and not ploughing and
digging the whole garden area. And this type of bed only uses one quarter the
area to produce the same quantity by other methods. Some of the advantages of
these types of beds are lots of pore spaces for air , water and roots ; even
distribution of moisture as water can pass easily through it ; the beds are
full of nutrients and organic manner provided by compost ; more varieties of
crops which are closely spaced and acts as live mulch and these beds are like
cultivating diversity . The roots do not spread out in search of water and
nutrients as they penetrate further down in the soil . As the roots are not
spreading and going down plants can be spaced more closely in a bio intensive
raised bed. The most important aspect of the bed is that water is easily
available to plants as the water holding capacity of the soil increases in the
loosened compost enriched soil.
The important fact
about a raised bed is that we are looking back to the nature and we can also
make the soil as required by different kinds of the crops. It is the best way
to harness the microorganisms required for plant nutrition. The different type
of crops planted in the raised beds also confuse the insect pests which is very
important in organic farming. In hilly areas this type of beds maintain the
soil moisture and is very important way of controlling soil erosion .
BIOINTENSIVE RAISED
BEDS:
This is a different way of looking at farming giving you a plan to raise crops
and also look at how double digging helps and how to build a compost pile as
lot of compost is needed to build a raised bio intensive bed . The beds are
very simple to create and maintain and can be built with locally available
resources. The bed needs less labour which can also attract new generation to
farming making it simple and stylish . the garden looks very good and saves
lots of money spent on tillage operations. The top soil needs many years to
form and is full of beneficial microbes and intensive tillage operations
destroy the top soil in few hours . The deficiency of soil microbes and organic
matter the soil depends on lots of chemical inputs . These are bio dynamically
made raised beds which is the storehouse of effective microbes and makes the
plant grow strong. The main principle involved in a bio intensive bed is
recycling of nutrients and replenishment of organic matter . Grow only that
much that the soil can support . It is also important to maintain the fertility
of the farm soil with the resources present in the farm itself . Doing so we
also can grow more nutritious food .
Composting is an
essential part of raised bio intensive bed farming . Hence , it is also
important to grow compost crops to make sufficient compost piles in the farm .
Before going to make the raised beds we must develop the habit of composting .
Composting is one of the ways to feed a bio intensive bed apart from making
lots of compost tea , panchagavya , amrit pani and different liquid formulas
made with the local resources .
COMPOST :
Composting is a
method of converting agricultural wastes and farm biodegradable resources to
humus . The time period of composting may vary from 45 to 60 days .
Materials required
for composting :
v
Nitrogenous material with high
nitrogen content like green plants , kitchen wastes , dung and other animal
manure , etc.
v
Carbonaceous material with high
carbon content like straw , dry leaves , post- harvest crop residues , dry
water hyacinth , dry sea weeds , etc.
v
Fresh cowdung , cow urine ,
jaggery or plaintains , rice strarch.
Steps involved in
composting :
v Site
selection : The composting site should not have water logging . Composting
should be done at least ten meters away from an existing tree . The site should
be permanently earmarked for composting as desirable microorganisms will be
developed in the soil beneath that will fasten the composting process and the
subsequent heaps .
v Size
of the heap : The size of the heap should be 8 ft long and 3 ft wide.
v Composting
method :
v Clean
the area by removing the grasses and other weeds .
·
Mark the area 8 ft length wise
and 3 ft wide .
·
Make an inverted ‘V’ channel with
the help of dried sticks at the centre of the marked area . This will help
aeration in the heap .
·
Spread all the carbonaceous
materials (dry leaves) above the inverted ‘V’ shaped channel within the
earmarked area up to a height of 30 cm .
·
Spread the cowdung slurry mixed
with cow urine , jaggery or plaintain , rice starch mixed in following
proportion :Fresh water : 100 litres; Fresh cowdung : 30 kgs ; Cow urine : 3 litres ; Jaggery /
Plaintain : 250 gms / 15 ; Rice gruel : 1 litre.Spread about 10 litres over the
dry leaves.
·
Spread the nitrogenous materials
(green biomass) up to a height of 30cm . Sprinkle about 10 litres of the slurry
over it .
·
Compact the layers with a bamboo
or a wooden block .
·
Repeat a layer of dry leaves of
30 cm and spread 10 litres of slurry followed by green layer of 30 cm and similarly add the slurry above it and
compact the layers .
·
Repeat the process until the
height of the heap is about 2 ft .
·
Cover the heap with moist gunny
bags or straw or can be plastered with mud and cow dung .
·
Apply time to time water to the
heap to maintain moisture level at 60% .
·
After 21 days turn the compost
heap and apply a mixture of 5 kgs fresh cow dung , 2 litres cow urine and 50
gms jiggery and 10 litres water over it
and again cover it with moist gunny bags .Harvest the compost after 45 days .
MAKING A
BIOINTENSIVE RAISED BED:
The first step involved
in making a garden is to think about the beds : placement , size and
arrangement . Depending on the availability of sunshine in the garden we should
plan the beds . The beds should be made always in the North-South direction to
ensure equal distribution of sunshine . The size and shape of the beds depends
on the size of the garden . The minimum size should be at least 3 feet by 3
feet for food production . Paths of the garden should be made keeping in mind
that maximum space of the garden is utilized for growing crops .
How to prepare a
double – digging raised bed :
The best bed
supporting strong plant growth is loose soil to a depth of 24 inches that
allows the roots of the plants to grow evenly and supplies adequate nutrition
to the rest of the plants . So when the soil is loose and deep the roots grow
straight and deep allowing more plants to be accommodated in a close spacing so
that we can produce more food from a smaller area . To start a new bed
following are the steps required :
Ø Decide
the size of the bed and put stakes to mark the each corner .If the soil is hard
and dry , water the bed area with sprinkler and allow the water to seep down
for at least two days ahead of the making of the bed .
Ø Use
a fork to loosen the soil 12 inches deep . and remove all the grasses and weeds
.
Ø Water
lightly for one or two days to break the clods if they are big. Let the soil
rest for one day.
Ø Start
double digging :
o
Dig a trench of one foot wide and
one foot deep on one side of the bed . Remove the soil and store it in a bucket
.
o
Loosen the soil in the trench and
with the help of a fork and put the fork 12 inches and loosen the soil .
o
Dig out the upper part of the
second trench made in the bed adjacent to the first trench .Make the trench of
one foot wide and one foot deep and spade out the loosened soil and put it in
the upper part of the first trench. Try to mix the soil layer as less as
possible . Microorganisms in soil live in different layers and less their living quarters are disturbed
during digging the bed they will be more actively involved in providing
nutrients to the plants .
o
Loosen the lower level of the second
trench upto another 12 inches and move on doing the third trench and go on
until the whole bed is covered .
o
The last trench might not require
the soil fom the first trench as the breaking down of the compactness and
making the soil more friable will increase the coverage of soil .After that
rake the whole bed .
o
Now with the help of bamboo ,
make a six inches height walling of the raised bed
o
Put a layer of compost followed
by a layer of top soil from the forest or the portion left between two beds .
o
Put a thin layer of vermicompost
followed by a layer of compost and the top soil
o
Sprinkle Amrit pani (Cowdung +
Cow urine + Jaggery +water ) to the soil layer and ensure that you have made a
6 inches raised bed .
o
At the top layer of the bed apply
compost and start planting the plants and apply some vermicompost over them .
o
Avoid recompaction by not moving
around the beds by walking .
o
The time required to make a bed
for expert may be 1 – 2 hours but new people might need a whole day .
o
You can also develop a bamboo
frame and put UV stabilized films to transform it to a simple method of growing
all season vegetables .
o
Time to time application of
compost tea or panchagavya or amritpani is required .
o
Mulching with live mulch like
local medicinal plants or mulch with straw or mulch film . You can even use
micro irrigation systems on them like drip irrigation and sprinkler .
PLANTING ON RAISED
BEDS :
Hexagonal spacing :
The best way to
plant on raised beds is hexagonal spacing in which you can accommodate more
plants. 10 percent more plants can be accommodate by this way of planting. If
square spacing is given there will be certain free spaces which will result in
compactness of those areas which is not desirable on raised beds. With
hexagonal spacing the leaves will touch each other on all sides and will create
a mini climate which is called “Living Mulch” which is very much needed in this
era of water shortage.
Insect pest & Disease control in the raised beds :
v To
control soil insects like ants (during seed sowing as they take away the seeds)
and red ants and termites , take a coconut shell or a plastic glass . Make some
holes on the shell or the cups at the base on the sides and place some jaggery
on the shell or the glass and place them on different places on the bed . Time
to time remove the ants that come inside the shell and the cup. They get busy
with the piece of jaggery and the seeds are saved .
v Regular
monitoring and hand pricking.
v Use
a light trap in the garden from evening when the darkness starts uptill 8 pm .
Do not put beyond 8 pm as beneficial insect’s moths may also be trapped.
v Reuse a mineral
water bottle to make a yellow trap . Colour the bottle with yellow colour and
put some sticky material on it like some castor oil . Put the inverted bottle
on a bamboo stick and install them at crop height in the raised beds. It has a
very effective control against sucking insects like aphids and white flies . It
also attracts fruit flies on gourds . Yellow colour tins or plastic bags can be
also reused.
v Mix
raw cowdung with neem leaves and castor leaves and make the cowdung into cakes
and dry in shade . The dry cowdung cakes should be burnt in the beds to
fumigate in the evening . The ash can be sprinkled over the bed as fungicide .
v Follow
crop rotation practice in the bed and making permanent raised beds make it easy
to rotate the crops . For example rotating groundnut with maize will reduce the
attack of white grubs. Rotating pigeon pea or chickpea with other
non-leguminous crops help to control fusarium-wilt and nematode problems.
v Use
of trap crops like the marigold in the bed. Insects are strongly attracted to
certain plants and when these are planted along the border they will gather
them rather than on the border . Later they can be easily destroyed .
v Mustard
is a trap crop along with cabbage for the control of Diamond back moth , aphids
and leaf miners. Maize plants are trap for fruit flies of vegetables .
v Intercropping
also adds to pest control as insects find difficult to locate the host plants .
Even chemical stimuli for the host plant is not so strong and aromatic odours
of other plants can disrupt the insect’s ability to locate such host plants
.For example cabbage intercropped with carrots and tomatoes is a good strategy
to control diamond back moth .Green gram intercropped with sugarcane reduces
the incidence of Sugarcane early shoot borer .
v Always
preference given to local varieties of crops is a good strategy to have less
insect and disease incidence in the beds as most of them are resistant to those
problems .
v Botanical
extracts like the five leaf extract , ginger-garlic-chilli extract , Neem seed
kernel extract etc can be used in pest and disease control .
v Feed
the soil well with compost , vermicompost and other liquid formulas like
panchagavya , amrit pani etc are good to make the plant strong to resist insect
and disease attacks . So Raised Bio intensive beds are the best control for
soil borne diseases.
v Cow
urine based sprays can reduce the incidence of diseases in the raised beds.
v A
variety of weeds which have pesticidal properties are used to make liquid
manure mixed with animal dung can be very effective in pest control and
nutrient management in the beds.
Some Advantages of
Raised Bio intensive beds :
v Easy
operation and cost effective . It can be developed with all the resources found
within the farm . The beds can be made with bamboo or wooden pieces or banana
pseudostem . Beds made with bamboo and wood become permanent for 3-4 years .
Concrete raised beds can also be made .
v More
economic benefit from small space :
With
hexagonal spacing we can accommodate more plants in the raised beds and from
small area we can have more profits . From my experiments we have made at MD’s
Organic farm we have Raised bio intensive
beds of 4 feet by 10 feet accommodating 60 local variety of chilli plants and recorded a harvest of 510 kgs of chillis over
a period of three months . Sold at 50 INR per kg the bed gave us 25500 INR . No
money spent on inputs we only incurred cost on bamboo , labour cost and three
drip lines along with 50 sqr ft UV film and the investment came up to about
5000 INR. One Raised bed of 3 ft by 20 feet in the farm can accommodate 100
plants of local tomato variety and can be intercropped with coriander and local
nutritious herbs .
v Raised
bed provides more nutrition to the plants and is the storehouse of beneficial
microbes . The water holding capacity of the beds is good. In hilly region it
helps to control soil erosion and also enhance permanent cultivation rather
than shifting cultivation .
v The
crops have less diseases on Raised beds and as the roots can go deeper we can
accommodate more plants to increase the per sqr foot income. The production is
four times higher on raised beds from our experiments at MD’s Organic farm.
v Youths
find it good to work as less labour and the garden look beautiful and planned
with raised beds . Good tool to attract young generation towards stylish
farming.
v You
donot destroy the topsoil with lots of intensive tillage operations . The
topsoil remain intact and composting helps reuse and recycling of the farm
wastes.
