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| AGRICULTURE TRIBUNE | Monday, March 11, 2002, Chandigarh, India |
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Managing soil activity for sustained production Boosting organic farming
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Managing soil activity for sustained production Farm soil may be visualised as a porous mixture of
four constituents — mineral material, organic matter, air and water.
In addition, the soil harbours a varied population of living
organisms. Well-managed productive soil in optimum condition for plant
growth contains nearly 45 per cent mineral material, 5 per cent
organic matter and 25 per cent each of air and water by volume. The
mineral component is made up of sand, silt and clay fractions. Of
these, only clay is very active chemically, whereas the others are
inert. Organic matter also called "humus" in its relatively
stable state, though present, in soil in very small amount, is
extremely active chemically. Air and water occupy the pore spaces in
soil. The contents of these two components in a given soil are
inter-related and undergo great fluctuations under field conditions.
The ideal farm soil contains optimum quantities of all the four
constituents. Sources of Activity: Above soil vision point out
that clay and humus are two major centres of soil activities. These
activities of clay and humus are on account of their colloidal nature,
characterised by a large surface area per unit weight and presence of
surface changes. As a result, these colloidal constituents, support
number of soil phenomena, including chemical reactions, nutrient
exchanges and water absorption. Moreover, both the colloids by
attracting nutrient cations from the soil solution to their surfaces,
temporarily protect them from leaching and then release slowly for use
of growing plants. Furthermore, clay and humus on account of surface
charges, bind coarser particles together and, thus, improve physical
condition of soil as in case of very sandy soil. Potential source
of activity: Out of the two sources of soil activity, clay content
of field soil is not subject to any major alterations. The clay
content of any field soil is its basic property. Even very harsh and
active weathering processes fail to alter appreciably the size of the
individual soil particles. Thus, the sandy soil remains sandy and
clayey remains clayey. Organic matter, the other source of activity,
is not as stable as clay. It is a transitory soil constituent. In
cultivated farmlands, its content undergoes wide changes due to
climatic conditions and crop management practices. Harsh climatic
conditions prevailing in arid and semi-arid regions cause severe
losses of organic matter. Poor crop management practices, accelerate
depletion of this vital soil component. Such natural and accelerated
losses of organic matter can be corrected by treating the soil with
organic manures. These manures are very rich, potential and renewable
sources of organic matter. They also serve as major sources of
phosphorus and sulphur and a sole sources of nitrogen. Besides, these
help to maintain an adequate supply of iron and other trace elements
in a farm available to plants. Furthermore, these manures serve as a
source of energy for micro-organisms whose activities are vital for
good soil health. Organic matter, thus, being the backbone of the soil
must be renewed constantly for sustained production. Sources of
organic matter: Bulky organic manures are rich sources of organic
matter. These manures include green manures, farmyard manure, farm
compost, urban compost, night-soil, sludge and other bulky sources of
organic matter. Out of these, green manure, farmyard manure and
composts are by far the most important and most widely used. Crop
residues also make significant contribution to organic matter content
of soil. The practice of burning crop residues causes great loss of
organic matter resulting in decline of soil activity. Ploughing under
of suitable green manure crops when in succulent stage not only
supplement large bulk of organic matter but also add adequate
quantities of nitrogen. Farmyard manure application done at the usual
10 to 15 cartloads per acre maintain on an average 400 to 500 kg dry
matter on a yearly basis. Treatment of the soil with 10 to 15 tones
of well-rotten compost keep the soil in active state for two to three
crop seasons, depending upon climatic conditions and crop management
practices. Rotational manuring for managing activity: In view
of great importance of bulky organic measures in ameliorating soil
activity, their periodic use in culturable lands should form a regular
practice. However, on account of poor adoption of green manures and
limited availability of farmyard manure and composts, most of the
farmers either miss or very much delay their application. To overcome
such a problem, rotational or phased-out system of manuring can be
successfully practised to replenish organic matter. The rotational
system consists in planned treatment of one-half or one-third of
farmland with the available manures every year in a regular sequence.
By extending this practice to the remaining land during the subsequent
two or three years, each field at the farm will receive organic manure
treatment regularly at an interval of two to three years. This
rotational system of manuring needs to be included in the integrated
nutrient schedule of the farm for the long-term management of soil
activity ensure sustained production. |
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Boosting organic farming According to Mr K.C. Pant, Deputy Chairman of the
Planning Commission, the government has decided to encourage the
organic farming in the country in a big way. Indeed, as pointed out by
Mr Pant, in the wake of the negative fallouts of the high-tech farming
based on costly and ecologically disruptive chemical fertilisers and
pesticides, the concept of organic or sustainable farming is picking
up in the country. As in the West and India, the buyers are prepared
to pay a premium on organic food. Significantly, popularisation of
organic farming by the Deccan Development Society (DDS) in about 40
villages of Medak district in Andhra Pradesh has resulted in putting
an end to the spell of drought by making these villages
self-sufficient in food, fruits and vegetables. The novel concept of
circle planting pioneered by the DDS has brought immense benefits to
the villagers in this part of Andhra Pradesh. Circle planting makes it
easier to water the trees. Normally, when trees are planted in a line,
they have to be watered separately, but in a circle they can be
watered once from the centres. There is also less shading of the
adjacent crops. Says Dr S. Venkat of the DDS, "All its nutrition,
all its water is found within the system itself. For any system of
production to be sustainable, the needs of the system must be found
within the system. Unless all the needs are found within the system,
the system will become unsustainable." The use of biofertilisers
and oil cakes and oil meals play a key role in the practice of organic
farming. The New Delhi-based National Academy of Agricultural Sciences
(NAAS)has stressed need to evolve new strategies to achieve a balanced
and integrated management of a organic and inorganic nutrients to
support organic farming. In fact, the much-touted Green Revolution
relying on the high yielding, vulnerable varieties and an abundant
supply of water has failed to be an economically viable or
ecologically sustainable farming strategy. In fact, the crisis facing
the farmers in Punjab is traceable to the pitfalls of the Green
Revolution strategy. A recent scientific study by the American
National Science Academy comes to the conclusion that the application
of pesticides and fertilisers does not necessarily lead to better
farming than the natural farming. Perhaps the credit for putting
natural farming on practical footing on a global scale goes to
Japanese plant pathologist Fukukoa who secured an Forward for the
signal service rendered to the cause of natural farming. A staunch
believer in the principles of Zen Buddhism, Fukukoa says that the soil’s
nourishing qualities stem from organic matter that return to soil
periodically. On the other hand, Dr Teuro Higs, agricultural
scientist and an advocate of nature farming points out that the
concent of nature farming seeks to re-establish the balance of energy
in nature without using pesticides and chemicals. "This ancient
technique of nature farming is based on sound ecological
principles", says Dr Higs. No wonder, organic farming is becoming
popular in both the developed North and the developing South. |
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Farm operations for March Vegetables Chilli and capsicum: Sow CH-3/CH-1/Punjab Guchhedar/Punjab Surakh/Punjab Lal varieties of capsicum. Mark east-to-west lines 45 cm apart with a rake or rope. Apply 40 kg of CAN, 155 kg of superphosphate and 50 kg of muriate of potash in bands over these lines and prepare rides. Dibble (chutki) 3 to 4 seeds per hill on the southern slope of each ridge, keeping hills 30 cm apart. Use 1.5 kg seed per acre of both chilli and capsicum for dibbling. In case nurseries have been sown in November-December and kept under protection against frost during winter, transplant them also on the rides and continue irrigation after 10 to 12 days. Sow 0.5 kg seed of chilli on raised beds.One-marla bed area is enough to raise seedlings for an acre. Treat the seed before sowing with Captan/Thiram. Onion: — From March 15, sow nursery of onion variety N-53 or Agri Fond Dark Red to produce bulb sets for planting Kharif season crop. Sow 5 kg seed to produce enough bulbs sets for planting in an acre. Sow this seed on beds having an area of 8 marlas.— Onion thrips feed on foliage and produce white spots followed by curling — a condition known as "silver top". Spray 250 ml of Malathion 50 EC in 80 litres of water per acre as soon as the pest appears. Okra: — Sow either variety Pusa Sawani or Punjab Padmini or Punjab-7 or Punjab-8 for better yields in this season. Apply 60 kg of CAN and 155 kg of superphosphate and 40 kg of muriate of potash per acre in bands and prepare rides from east to west. Soak 8 to 10 kg seed in lukewarm water over night. Dibble 4 to 5 seeds per hill on the southern slope of ridges, keeping hill at 30 cm. Apply light irrigation after 10 to 12 days.— Spray one litre Stomp 30 EC/acre as pre-emergence to control weeds. Cucurbits: — Apply 155 kg/acre superphosphate and 40 kg/acre muriate of potash. Prepare channels as per recommendation of each cucurbitaceous vegetable. Soak the seeds in water, wrap in a woollen rag of 48 hours of pre-sprouting. Use 2 kg of seed for covering an acre. Dibble at least two viable seeds per hill.— After germination of the crop, apply 2.75 kg/acre Furadan 3 G 3-4 cm deep in soil just near the base of plants or apply 75-100 g/acre of Sevin/Hexavin 50 WP in 50-100 litres of water to check attack of red pumpkin beetle. Pea and early season Varieties of
cauliflower:
— Harvest
the seed crop of pea when few top most pods are yet slightly green.
This will check shattering of seeds in the fields. — Harvest the
seed crop of cauliflower when the top most pods in bunches of early
season varieties are yellowish green. Tomato:
— Late blight disease may appear on tomato early in
this month. The crop may be sprayed with Indofil M 45 @ 600 g/acre to
control this disease. In case of severe infestation, spray Ridomil MZ
@ 500 g/acre followed by Indofil M-45 at 7 days interval. — Spray
tomato crop with 800 ml of Thiodan 35 EC or 800 g Sevin/Hexavin 50 WP
or 100 ml of Sumicidin 20 EC or 40 ml of Ambush 50 EC or 200 ml of
Ripcord 10 EC or 160 ml of Decis 2.8 EC per acre in 100 litres of
water to check attack of the fruit bore. Cowpea:
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