Research Methodology

Land preparation and planting of seedlings is necessary in order to take full advantage of the growing season and thus obtain high yields. Appropriate mechanization will help farmers to carry out all farming operations, including efficient land preparation in a timely manner.

Rice fields can be prepared in three different ways: (3.4.1) puddling to turn the surface soil to mud, (3.4.2) unpuddled aerobic soil cultivation and levelling, and (3.4.3) raised bed land preparation.

3.4.1. Puddling to turn the surface soil to mud

This is the most common method farmers use to puddle the soil and turn it to mud prior to transplanting young rice seedlings. This is the most common and generally the best practice for low lying lands which are likely to get flooded during the rainy season.

 Animal or hand pulled tractors, or a four wheel motorised tractor, can be used for land preparation.

 Spread out residues from the previous crop and then incorporate these residues and/or organic manure and compost, during the first plowing.

 Then irrigate the field and allow 15 days for weed seeds to germinate and for organic matter to decompose.

 Apply (broadcast uniformly) a phosphorus fertiliser, and also make the first application of a potassium fertiliser. Do this prior to the 2^nd ploughing.

 Plough the 2^nd time to uproot all germinated weeds and to incorporte P and K fertilisers.

Then puddle the soil and level the field by using a thin film of water (Fig. 5). Field levelling is very important for obtaining a good germination of seeds, or a uniform establishment of transplanted seedlings. The objective is to get vigorous early growth (aim for full canopy development to assist in suppression of weeds), and a water efficient irrigation.

 Repair and reshape field bunds and plug or destroy all rat holes to minimise rat damage during seedling growth and grain filling periods.

(a) (b) (c)

FIG. 3.5. Land preparation by puddling and levelling in a flooded field: (a) Levelling with an animal-drawn leveller; (b) Levelling by hand-tractor-animal-drawn leveller; (c) Puddled and levelled field ready for transplanting (Source: www.knowledgebank.irri.org/).

3.4.2. Unpuddled aerobic soil cultivation and levelling

The methods are similar to preparing land for crops like maize, soybean or wheat. The details are as follows:

 An animal drawn plough, a hand held tractor, or a four wheel motorised tractor can be used for land preparation. Till the field when the soil is moist and friable (Fig. 3.6a).

 Spread out and incorporate into the soil all residues from the previous crop and the weeds that have grown during the fallow period. In addition, farmers can apply organic manure and or compost and incorporate it into the soil during the first plowing.

 After the first plowing, the fields will appear rough with large clods (Fig. 3.6b).

 Wait for the first rain, or irrigate the field (if possible) and allow 15 days for weed seeds to germinate and for organic matter to decompose in moist soil.

 Apply (broadcast uniformly) a phosphorus fertiliser, and also make the first application of a potassium fertiliser prior to the 2^nd plowing.

 Plough for 2^nd time to uproot the germinated weeds, then harrow and finally level the soil under dry condition to get a smooth seedbed (Fig. 3.6c).

 Alternatively, a tractor with an attached rotovator is used to till and level the soil (Fig.

3.6d). Field levelling is very important for obtaining a good germination of seeds and a uniform emergence of seedlings throughout the field. The objective is to get vigorous early growth (aim for full canopy development to assist in suppression of weeds), and water efficient irrigation.

 Repair and reshape field bunds and plug or destroy all rat holes to minimise rat damage during seedling growth and grain filling periods.

(a) (b) (c) (d)

FIG. 3.6. Dry land preparation: (a) First plowing; (b) Appearance of the soil with large clods just after primary tillage; (c) Well prepared dry soil after harrowing and levelling, ready for dry seeding; and (d) Using a rotovator for preparing dry or moist soil (Photos by V. Balasubramanian).

3.4.3. Raised bed land preparation – SRT (Saguna Rice Technique) method of cultivation of rice and other crops

100 cm wide raised beds are formed between 36 cm wide furrows for dibble sowing seeds of rice and other crops in rows. This is called Saguna Rice technique (SRT) and has been promoted in Thane, Raigad and Ratnagiri districts of Maharashtra State, India for more than 3

years by Mr. Chandrashekar Bhadsavle of Sagunabaug, Maharashtra, India [12]. The details of the SRT method are as follows:

 Prepare the land aerobically with one to two ploughings or one tillage with a rotovator, followed by one to two times each harrowing and levelling. Till the field when the soil is moist and friable.

 Mark long lines 136 cm apart along the natural slope of the field, with the help of a long twine or a rope (Fig. 3.7a).

 Use the furrow opener to make 36 cm wide furrows. Then use the soil from the furrows to make 100 cm wide raised beds between furrows and level the beds well (Fig. 3.7b, c).

 Make the furrows gently sloping along the natural slope of the field to help drain excess water, if necessary, during heavy rains.

 If irrigation is available, water is released into the furrows and allowed to move laterally to wet the beds. However, direct drip irrigation of the beds is usually the most water efficient method of irrigation.

 Once beds are formed, no tillage is practiced between crops and weeds are controlled by herbicides.

 Beds are reshaped by taking the excess soil from furrows and placing it uniformly on top of the beds once every year.

(a) (b) (c)

FIG. 3.7. Making raised beds and furrows in prepared field, Raigad, Maharashtra, India: (a) Marking lines to make furrows and beds, (b) making furrows and beds manually, and (c) making furrows and beds with furrow openers attached to a tractor (Photos by Chandrashekar Bhadsavle).