Rice

Land Preparation

Importance Of Tillage Land Levelling Preparation of main field Most commonly used equipments

Importance Of Tillage

Land Preparation and Levelling

Importance

  • Timely land preparation can ensure planting at an optimal time.
  • Mobility and tillage depth depend largely on water management.
  • If the soil is kept wet and soft, then all equipment – especially larger equipment – will tend to sink, create problems of mobility and tillage depth. When tillage layers are too deep then subsequent operations such as walking, movement of power tiller or combine harvester can have problems.
  • Tillage can reduce weed burdens. Till on moist soil and re-till after two weeks just prior to planting to kill germinating weeds.
  • Soil does not have to be saturated for residues to break down.
  • Residue decomposition is best at soil moisture levels of a moist but well drained field (i.e., less than field capacity) or the soil should be just wet.

Typical comparison of tillage systems and time required : System hrs/ha: Animal120 – 135, Hand tractor40 – 604, Wheel tractor5 – 10

Two major systems of rice cultivation namely

  • Dry or upland system and Wet system are existing in all rice growing areas.
  • In upland system the crop is grown under rainfed conditions on dry ground as in case of other cereals.
  • In wetland system the land is flooded and puddled where the crop is grown in standing water.
  • More specifically rice is cultivated in four systems like:
    • Upland
    • Irrigated
    • Rainfed lowland and
    • Deep water
  • The land preparation varies with the system under which rice is cultivated.

Soils suitable for raising the crop

  • In Tamilnadu, the paddy is grown in loams, mixed red and black soils, deltaic alluvial soils, deep and medium deep black soils, red loams and coastal alluvial soils.

Summer ploughing

  • Summer ploughing is resorted to in the dry and semi-dry system (upland rice culture)
  • This system is mostly confined to the tracts which depend on rains and do not possess adequate irrigation facilities.
  • In the semi dry system the rain water is allowed to get accumulated in the field when the crop is 5-6 weeks old.
  • In this system, the field is provided with deep summer ploughing 40-45 days prior to the onset of monsoons.
  • The next widely adopted system is irrigated system otherwise known as wet system.
  • In this system seedlings are raised in the nursery bed and later transplanted in puddled mainfield.

The main object of raising seedlings is to

  • Obtain healthy planting material,
  • Utilize the mainfield till the seedlings become ready,
  • Minimize the cost by using less seed material etc.

Wet nursery

The area intended for nursery raising should have;

  • An assured water supply and an efficient drainage system.
  • Should be dry ploughed twice and later, it should be irrigated and allowed to be wet for another two days.
  • Afterwards it should be puddled twice and the puddling may be repeated after a gap of one week.
  • This process of puddling contributes in obtaining good tilth, removal of weeds and also facilitates water retention.
  • To plant one acre, 4 cents of nursery is required
  • Recommended inorganic fertilizers are to be applied after first phase of pudding.
  • After levelling and final puddling, beds of convenient length with width of 1.5 m are to be made, leaving 50 cm channels in between two beds.

Dry nursery

In this method;

  • The field is ploughed 5-6 times
  • Beds of 1.5 m width and convenient length are to be prepared
  • Channels are to be provided for irrigating and draining of the beds
  • After preparing the beds they are to be wetted
  • For 10 cents of nursery beds 500 kg of well rotten FYM, 1.25 kg of P2O5 and 1 kg of potash need to be applied and incorporated with spades.

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Land Levelling

  • Levelling helps in bringing puddled undulated 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 turn for early tillering.
  • Better utilization of nutrients by managing uniform depth of water throughout 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 crops can be achieved.
  • Oxygen diffusion is more uniform.
  • Reduction of deep percolation of water and inputs to a certain extent.

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Preparation of main field

  • The main field is to be dry ploughed for twice three weeks before planting .
  • Later, field may be ploughed with 5-10 cm of standing water 2-3 times. This process is known as puddling
  • Dry ploughings may be carried out with tractor or power tiller.
  • If country plough is used, the ploughings have to be increased.
  • The application of 12.5 tons of farm yard manure or 6.25 t of green manure per ha and its incorporation by puddling is recommended. This operation facilitates better decomposition of the manure and/or the green manures.
  • The fertilizers recommended for basal application have to be applied before the last puddling and incorporated.
  • Later, proper levelling has to be made before transplanting the seedlings. Sometimes irrigation water is received late in the season due to delay of monsoon rains or insufficient rainfall.In such occasion the field has to be ploughed cross wise with the receipt of first monsoon rains.
  • For rainfed rice cultivation dry ploughing should be done to get fine tilth with the available rains and soil moisture. Then level the land perfectly and provide shallow trenches (15 cm width) at an interval of 3m all along the field to facilitate draining excess water at the early growth stage.

Land preparation for problem soils

  • In fluffy paddy soils compacting of the soil should be done once in three years at proper moisture levels by passing stone rollers or stone filled oil-drums. This will prevent sinking problems during puddling operations.
  • For sodic soils 50 % of recommended Gypsum is applied during the ploughing operation at optimum moisture condition. Allow water to stand and then provide drainage for leaching out soluble salts and apply green leaf manure @ 5 t/ha, 10 to 15 days before transplanting. Mix 37.5kg of Zinc sulphate per ha with sand to make a total quantity of 75kg and spread the mixture uniformly on the levelled field. Do not incorporate the mixture in the soil.
  • For saline soils provide proper drainage channels of 60cm deep and 45cm wide, apply green leaf manure @ 5 t/ha at 10 to 15 days before transplanting. Apply 25% extra dose of recommended nitrogen and 37.5 kg ZnSo4 per ha at the time of planting.
  • For acid soils apply lime @2.5 t/ha before last ploughing. This should be followed upto 5th crop.
  • For soil crusting and soil hardening problems basal application of gypsum @ 1 t/ha is recommended.

Digging corners and maintenance of bunds

  • Dig the corners of field which are not covered by ploughing
  • Cut off 2.5 cm of soil from the top and sides of the bunds to remove the weeds along with their seeds and to destroy the eggs of insect pests by using mammutty
  • If the bunds are very broad, trim them to a width of 15 cm and height of 15 cm so that rats do not harbour in the bunds If rat burrows are noticed, insert pellets of 0.5 g or 0.6 g aluminium phosphide and plug the exit holes
  • Apply mud paste to the side and top of the bund to a thickness of 2.5 cm with a mammutty and plaster it using the flat surface of the mammutty. Plastering the bunds helps in checking weed growth and prevents harbouring of insect pests.

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Most commonly used equipments for tillage operation

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 soft.
  • Puddling is done in 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 Frame

  • The frame consists of front piece, the rear and side pieces made of steel angle section or wood.

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.

Metal cross :

  • Metal cross holds the paddles in position.
  • It’s made of mild steel flat.

Axle :

  • Axle is made of mild steel bar of about 25 mm in diameter or of mild steel pipe.

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.

Handle :

  • Wooden handle is attached 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 thoroughly 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 39 m/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 transplanitng.
  • 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.

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Tamilnadu

Rice

Rice Management