Broad Bed and Furrow System (BBF)
for Soybean in Madhya Pradesh
Lakhan Patidar
Generate a good income from farming
in Rainfed areas is not very easy. Fluctuations in timing of onset of monsoon,
erratic rain distribution during the crop season, sudden occurrence of high
intensity rain storms and absence of in-situ water harvesting systems are major
constraints in crop production in these areas. Although the amount and timings
of precipitation received by crop cannot be altered but proper management of
its utilization can improve crop yields.
In irrigated
farming, planting on flat lands and flood irrigation are commonly used
practices. Main problems associated with such practices include higher input
use (such as irrigation water, fertilizer, manpower etc.), declining water
table because of over exploitation of ground water resources for irrigation,
greater downward movement of water fertilizer and pesticide below root zone. Higher
pest incidence and poor control of weeds and diseases. Thus in irrigated
farming also, although intensive agriculture has brought substantial
enhancement in production of food grains but it has threatened the environment
safety and promoted' the degradation and inefficient use of basic resources
such as land, water and fertilizer and also increased input cost which
ultimately reduce the net income of farmers. Hence there is a need to manage
both rain and irrigation water efficiently by adopting appropriate soil
management technology.
Broad
Bed and Furrow System (BBF)
The Broad Bed and Furrow system has
been mainly developed at the International Crops Research Institute for the
Semi-arid Tropics (ICRISAT) in India.
It is a modern version of the very old concept of
encouraging controlled surface drainage by forming the soil surface into beds.
The recommended ICRISAT system consists of broad beds about 100 cm wide
separated by sunken furrows about 50 cm wide. The preferred slope along the
furrow is between 0.4 and 0.8 percent on vertisols. Two, three, or four rows of
crop can be grown on the broad bed, and the bed width and crop geometry can be
varied to suit the cultivation and planting equipment.
In India the
system has been used mainly on deep vertisols (heavy black clay soils sometimes
called cotton soils), wide beds are used on a gentle grade and they are formed
by ox-drawn wheeled tool carriers.
The BBF system of sowing has the following
objectives:
- To encourage moisture storage in the
soil profile. Deep vertisols may have soil moisture storage up to 250 mm, which
is sufficient to support plants through mid-season or late-season spells of
drought. The possibility is also increased of double cropping by means of
inter-cropping or sequential cropping. The large water storage capacity of the
soil supports growth more easily during the subsequent dry but cooler
post-rainy season.
- To dispose safely of surplus surface run-off
without causing erosion from furrows.
- To provide a better drained and more
easily cultivated soil in the beds. There is only a narrow range of moisture
conditions during which the soil can be efficiently tilled or planted, and
timeliness is a key factor. Only about 20 percent of the deep vertisols in
India are cropped during the rains, mainly because of poor workability when
wet. If a crop can be established during the early rains, the profile is
usually near saturation only for short periods during the latter half of the
season, water is more efficiently utilized, and there is less need for run-off
collection and storage.
IV.
The possibility of the re-use of run-off
stored in small tanks. Small amounts of life-saving irrigation applications can
be very effective in dry spells during the rains, particularly on soils with
lower storage capacity than the deep vertisols.
Some other advantages of BBF planting method:
- Increase
in water use efficiency
- Increase
in crop productivity (5-10%)
- Less
moisture stress during non- rainy days
- Time
saving (25-30%) in irrigation
- Requires
20-25% lower seed rate
- Water
saving up to 25-30%
- Better
weed management
- Reduces
crop lodging
The
BBF system is particularly suitable for the vertisols. The technique works best
on deep black soils in areas with dependable rainfall averaging 750 mm or more.
It has not been as productive in areas of less dependable rainfall, or on
alfisols or shallower black soils - although in the latter cases more
productivity is achieved than with traditional farming methods. Other methods,
with more emphasis on storage and irrigation within a package which includes
BBF, are more likely to be viable for the alfisols.
An important component of the system is an ox-drawn wheeled tool bar, which
can be used with ridgers to form the raised bed and also later for carrying
precision seeders or planters. The tool carrier is thus used for the initial
forming of the beds, the subsequent annual reshaping, and for all tillage,
planting, and inter-row cultivation.
Fig: Structure of a sample Broad Bed and Furrow seed
drill.
A raised land configuration ‘Broad Bed Furrow’ (BBF)
system helps the soil to preserve the water level for a longer period. Holding
moisture intact, the bed stimulates crop’s growth. This
system would not only help in water conservation for better crop yield but also
help adapt to the ever changing climate. The crops will respond better to
fickle rain duration's and survive longer.
