Types of preparatory tillage

1. Primary tillage

2. Secondary tillage

♤ Primary tillage: The tillage operation that is done after the harvest of crop to bring the land under cultivation is known as primary tillage. Ploughing is the opening of compact soil with the help of different ploughs. Country plough, mould board plough, bose plough, tractor and power tiller are used for primary tillage.

♤ Secondary tillage: The tillage operations that are performed on the soil after primary tillage to bring a good soil tilth are known as secondary tillage. Secondary tillage consists of lighter or finer operation which is done to clean the soil, break the clods and incorporate the manure and fertilizers. Harrowing and planking is done to serve those purposes

♤ Dry tillage: Dry tillage is practiced for crops that are sown or planted in dry land condition having sufficient moisture for germination of seeds. This is suitable for crops like broadcasted paddy, jute, wheat, oilseed crops, pulses, potato and vegetable crops.

♤ Wet or puddling tillage: The tillage operation that is done in a land with standing water is called wet or puddling tillage. Puddling operation consists of ploughing repeatedly in standing water until the soil becomes soft and muddy. Puddling creates an impervious layer below the surface to reduce deep percolation losses of water and to provide soft seed bed for planting rice.

♤ Off-season tillage: Tillage operations done for conditioning the soil suitably for the forthcoming main season crop are called off-season tillage. Off season tillage may be

1. Post harvest tillage

2. Summer tillage

3. Winter tillage

4. Fallow tillage

♤ Special purpose tillage: Tillage operations intended to serve special purposes are said to be special purpose tillage. They are, 1) sub soiling, 2) levelling, 3) clean tillage, 4) blind tillage, 5) wet tillage and 6) zero tillage.

♤ Sub soiling: To break the hard pan beneath the plough layer special tillage operations (chiselling) are performed to reduce compaction. Sub soiling is essential once in four to five years where heavy machineries are used for field operations, seeding, harvesting, transporting etc.

Advantages

♤ greater volume of soil may be obtained for cultivation of crops

♤ excess water may percolate downward to recharge the permanent water table

♤ reduce runoff and soil erosion

♤ roots of crop plants can penetrate deeper to extract moisture from the water table

♤ Clean tillage: It refers to working of the soil of the entire field in such a way no living plant is left undisturbed. It is practiced to control weeds, soil borne pathogen and pests.

♤ Blind tillage: It refers to tillage done after seeding or planting the crop (in a sterile soil) either at the pre - emergence stage of the crop plants or while they are in the early stages of growth so that crop plants (cereals, tuber crops etc.) do not get damaged, but extra plants and broad leaved weeds are uprooted.

♤ Zero tillage (No tillage): In this, new crop is planted in the residues of the previous crop without any prior soil tillage or seed bed preparation and it is possible when all the weeds are controlled by the use of herbicides.

Advantages of Zero tillage

1. Zero tilled soils are homogenous in structure with more number of earthworms

2. Organic matter content increases due to less mineralization

3. Surface runoff is reduced due to presence of mulch

Disadvantages

1. Higher amount of nitrogen has to be applied for mineralization of organic matter in zero tillage

2. Perennial weeds may be a problem

3. High number of volunteer plants and buildup of pests

Do you know?

The National Green Tribunal (NGT) has constituted a high-powered committee of government officials to prepare guidelines for the restoration of the environment and ecology destroyed as a result of coal mining in Meghalaya.