Rice

Land Preparation

Equipments to be Used Land Levelling

Equipment Options And Use

  • Primary tillage options – Ploughs (Mould board, Disc, Tine, Offset)
  • Secondary tillage options – Disc Harrow, Offset Disc, Rotavator, Puddler,Landplane.

General Equipment use considerations:

  • Maintenance: Check and tighten bolts, grease high friction parts about every 8 hours of operation.
  • Operation speed: For tractors, operate at around ¾ full throttle. Many operations can be performed around 7-8 Km/hr. If rpm drop by more than 200 upon engagement of equipment, then use a lower gear.

Primary Tillage:

  • Ploughs (Mould board, Disc,Tine,Offset)

Disc Plough

Objectives

  • To obtain required tilth of 10-15 cm. depth.
  • To open soil for drying
  • To uproot stubbles and weeds
  • To burry trash under soil
  • To kill weeds

Key points

  • Power requirements are of the order of 14-26 k W/m at 7.2 km/hr
  • Stabilizer chains should be relatively loose (but not so loose that implement hits tires)
  • Plough should be level in two planes (front to back, side to side)
  • If the tractor is "Pulling" to one side, then the plough is not properly adjusted.
  • Depth of cut should be uniform – results if plough is level.
  • Field should be as level as possible after ploughing (no ridges)

Mould board plough and plough


  • The initial opening of wet soils can be done with minimum water in the field with a mould board plough fitted with disc or a plough.
  • The disc coulter helps to minimise the clogging of the mould board plough with weeds, stubble and the soil.
  • It takes nearly five days to complete the initial ploughing operation of one hectare.
  • Water is to be let in after the initial opening and left for a period of about one week for decomposition of the weeds and for complete soaking of the soil lumps.

Secondary Tillage


  1.Disc Harrow & Offset Disc
  2.Rotavator
  3.Puddler
  4.Land plane

Disc harrow and Offset disc:

Disc Harrow

  • The secondary tillage, consists of two operations by disc harrow completes the puddling of one ha in 12 to 15 hours.
  • In well soaked soil disc harrow can be used for puddling without initial opening and in such case 4 to 5 operations are generally required.
  • Disc harrow for puddling should be provided with scrapers for keeping the disc clean from mud and weeds.
  • A light type of tandem disc harrow (weight 40 kg) with 8 discs spaced at 13 cm each having a working width of 110cm in two gangs is very suitable for puddling operation.
  • The draft (97-122 kgs) of such a disc - harrow was less than that of wooden plough (136-160 kgs).
  • The yield of paddy crop from the field puddled by disc harrow was the highest in the field experiments, conducted on use of different type of bullocks – drawn implements.
  • Tandem disc – Two sets of gangs front and rear in the shape of an "X".
  • Front discs face out ward (and throw soil outward) – back discs face inward. Offset disc – Single front gang with single rear gang. Concave face of gang discs face opposite directions.

Objectives

Under wet (saturated) conditions

    1. To work soil 10-15 cm (4-6") deep.
    2. To tear up roots.
    3. To soften ground for subsequent puddler operation.
    4. To chopping , incorporation of straw & to kill weeds.

Key points

    1. Power requirements are of the order 14-18k W/m at 7.2 km/hr
    2. Stabilizer chains should be relatively loose (but not so loose that implement hits tires)
    3. Level in two planes (front to back, side to side)
    4. Main adjustment is top hitch
    5. As the angle of a harrow is increased, the depth of cut and increase.
    6. Front angle of discs is generally about 20o, and the back discs slightly more.
    7. Front disc blades wear faster than following blades
    8. Have bumper pads between center discs (to stop discs from knocking)
    9. Cut to a maximum of ¼ of the disc diameter
    10. Should leave a relatively flat surface – a depression or ridge in the middle of a tandem disc harrow indicated that disc spacing, working speed or top link of the three point hitch need adjustment

Don’ts

  • Disc cut should not overlap (i.e., back discs cut should be between front disc cut)
  • Don’t cut deeper than ¼ of disc diameter

Rotavator

Objectives

  • Develop suitable tilth for seed germination/planting
  • Kill weeds
  • Uproots straw.

Use of Rotavators should be limited, if possible as they:

  • Energy requirements are more than other land preparation equipment.
  • Involve a lot of moving parts so maintenance costs are higher. Often used for nursery seedbed.

Key Points

  • Power requirements are of the order 20-35k W/m at 7.2 km/hr
  • PTO shaft turns at 540rpm
  • PTO shaft should overlap by 10-15 cm.
  • PTO shaft should be horizontal to the ground when the rotovator is lowered and in use
  • Blade depth - the maximum cut should be approximately 1/3 of diameter

Don’t

  • In dry fields, you should not turn in the field with rotavator down .

Puddler

Objectives

  • Decrease weeds
  • Decrease percolation as a result of soil dispersion.
  • Level the soil for better planting conditions and/or for snail control (where a problem)

Key Points

  • Power requirements of the order 7k W/n at 7.2 km/hr
  • Puddlers should be used only when necessary for snail and water management.
  • Note: Rotopuddlers (e.g., those used at IRRI) can be used with a "Laser" guided System.

Comb Harrow

  • The comb harrow commonly used in the Philippines and recently introduced in India, is simple efficient one for puddling of wet field, after initial opening has been made by the plough.
  • The tines of harrow penetrate about 15 cm deep in the wet ploughed soil and effect puddling by stirring and combing action.
  • The weed stubbles and mud accumulated in front of the harrow are easily removed by tilting the handle forward and allowing the accumulated material to escape below the tines in course of operation.
  • The draft of the implement varies from 114 kg to 112kg which is with in the pulling power of a pair of average sized bullocks.
  • Two or three operations of the harrow are adequate to complete the puddling of wet soil after one initial ploughings by mould board plough.

Bullock drawn puddler

  • Puddler is used for preparation of paddy fields with standing water after initial ploughing.
  • It breaks up the clods and churns the soil.
  • The main purpose of puddling is to reduce percolation of water, to kill weeds by decomposing and to facilitate the transplanting of paddy seedlings by making the soil softer.
  • Puddling is done in a standing water of 5 to 10 cm depth.
  • A common puddler used in this country has three puddling units, each having 4 paddles mounted on an axle.
  • The axle with the puddling units is freely mounted on two bearings, fitted on a frame, made of metal or wood.
  • The weight of the puddler including its beam is with in a range of 30 to 40 kg only.
  • The puddler consists of:
    1. Frame: The frame consists of front piece, the rare and side pieces made of steel angle section or wood.
    2. Paddles: Paddles are made of mild steel sheets having a thickness of about 3.15mm. The size of the paddle is about 225 x 125 mm . The paddles are riveted to metal cross.
    3. Metal cross: Metal cross holds the paddles in position. It’s made of mild steel flat.
    4. Axle: Axle is made of mild steel bar of about 25 mm in diameter or of mild steel pipe.
    5. Beam: Beam is made of wood and is suitably fixed to the frame with the help of braces and the other end to the yoke for hitching to animals.
    6. Handle: Wooden handle is attached as handle supports for guiding the movement of the puddler.

Power tiller with a Rotavator

  • A 10 H.P power tiller with rotavator is very efficient in puddling of wet lands. Because of the wide difference between the linear speed of the tiller and the rotary speed of the rotavator, it is possible to get land throughly puddled to an observed depth .
  • Puddling and levelling or trampling of green manure crop can be done in one operation by other tiller keeping the rotavator on high speed (505) Rpm and tiller on low speed (24 to 39m/min).
  • Tractor with cage wheels:
  • A tractor with cage wheels and paddy disc harrow was studied for puddling operation. A minimum of three operations are required for a satisfactory puddle for transplanting.
  • It takes nearly seven to eight hours to prepare one hectare of land at an approximate cost varying from Rs.80 to 100, which is more or less comparable to the use of wooden plough in regard to cost.
  • The 35 HP MF tractor with a rotavator when used for puddling soil with 5 to 10 cm depth of standing water on the surface, required less man hours and has higher turn over as compared with disc harrow.
  • The depth of puddle and distribution of soil aggregate obtained with rotavator are in not in any way inferior to that obtained with paddy-disc harrow.
  • It has been also observed that practically little levelling is required after the puddling operation.
  • The land levelling is carried out with the following equipment. Land Plane Objectives:
  • Smoothen the land surface(not level)

Key points

  • A land plane will typically require 28 KW/m.
  • Should run at about ½ full (in practice, it may run empty 10-15% of the time)
  • The soil aggregate size should be less than the height of the cut
  • The cut will often be about 1 inch.

Other land levelling equipment

  • A ladder or a wooden beam is used for levelling, the leveller consists of a single plank held at an inclination to horizontal surface between two hinged side plates curved upward.
  • The inclined edge is provided with an angle iron while working in dry condition the weight of the implement and operation is confined to the sharp edge and thus make it more effective in breaking the clods as compared to ladder type where the weight is distributed over the entire surface area of the two plants.
  • Under wet conditions the side plants permit accumulation of water in front of the leveller making it float on the water and there by reducing its weight and the draft by 40% due to buoyancy, the implement of 2.5 m width has a comparable (even less in case of working under wet condition) draft to that of a 2 m ladder type leveller.
  • Mechanical paddy transplanter: Features of the machine:
  • Available with its own source of power of 3-HP diesel engine.
  • Covers eight rows at a time with a row to row spacing of 23 cm.
  • Provision to vary the plant to plant spacing – 10 and 12 cm.
  • Provision for cage wheel for field use and rubber wheel for transport.
  • Operation of the transplanter:
  • Check oil level in gear box, fuel tank and grease the specified parts.
  • While operating observe for any missing hills in any particular row and diagnose the problem immediately. The missing hills can be due to presence of stones/foreign matter that would have obstructed the fingers that pick the seedlings from the tray.
  • Choose the right speed of operation for a plant hill to hill distance of 10 or 12 cm.
  • Observe the number of plants per hill and adjust to the requirement using the lever operating the finger movement.
  • Observe the depth of planting the lever and adjust accordingly.Transplanter Operation: For efficient operation of transplanter the land preparation and knowledge of the mechanical provisions incorporated with the transplanter are essential to be known.

Land preparation

  • Puddle the land, level it and remove the water after 24 hours (for clayey) or 12 hours (for sandy/loamy soil) before the transplanting. In black or clayey soils the settlement is critical as the loosened soil can bury the seedlings planted.
  • Just before the operation of transplanter, a thin film of water is necessary to ensure the free movement of transplanter and avoid adhering of soil to the moving parts of the transplanter.
  • Performance: There will be a net saving of 40 per cent over the manual transplanting. It can transplant about one hectare in a day of 8 hour run. The transplanter performs with missing hills of 2-3 per cent.
  • Available Transplanters Now a days mechanical transplanting of paddy is also recommended and practiced in some places.
  • M/s Godavari farm equipment’s, Jagityala, Kharimnagar district developed a machine with modification of the machine originally fabricated by international rice research institute.
  • There are two types in this machine namely
    • V.G.T-6 and
    • V.G.T-8
  • which are manually operated.
  • With V.G.T-6 machine 6 rows could be planted at a time with spacing of 20 cm while V.G.T-8 type 8 rows could be planted at a time with spacing of 15 cms.
  • With V.G.T-6 eight cents of area could be planted per hour while with V.G.T-8 ten cents could be planted/hr
  • These machines are available for sale with A.P Agro Industries Development Corporation, Hyderabad
  • Engineering department of State Agricultural University(ANGRAU) has developed manual operated transplanter.
  • With this transplanter ½ an acre could be planted in a day.
  • To operate this instrument 3 persons are required.
  • The same agricultural university also developed a power driven machine for transplanting.
  • This machine covers two acres of transplanting in a day.
  • To operate this machine one man and two women are required.
  • M/s Escort & co. had developed a power operated machine for transplanting paddy seedlings.
  • For using this machine nursery has to be raised in plastic trays using 16 kg of seed in 80 plastic trays to cover an acre.
  • With this machine one acre could be planted in about 90 minutes.
  • These machines are available with Anna data agri pvt. limited, Rajamundry.
  • Though machines are available for transplanting, most of the rice growers are resorted to manual transplanting as on-to-day.

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Land Levelling

  • Levelling helps in bringing undulated field left over after puddling into levelled field
  • To maintain uniform depth of water in main field
  • To increase water use efficiency by maintaining shallow depths of water upto panicle initiation stage.
  • Maintenance of shallow water depth is possible only when the land is perfectly levelled.
  • Shallow planting is possible only at shallow water depth which helps in better seedling establishment which helps in term for early tillering.
  • Better utilization of nutrients by managing uniform depth of water through out the field
  • Perfect levelling helps in complete draining of water - facilitates easy harvesting of crop without loss of grain.
  • If a pulse is sown after paddy uniform establishment of pulse crop can be achieved
  • Oxygen diffusion is more uniform
  • Reduction of deep percolation of water and inputs to a certain extent.

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Andhra Pradesh