Tillage operations that are carried out from the time of harvest of a crop to the sowing of the next crop are known as preparatory cultivation. Generally, the terms preparatory cultivation and seedbed preparation are synonymously. Preparatory cultivation consists of three distinct operations viz.:
Primary Tillage or Ploughing: Ploughing is opening of the compacted soil with the help of different ploughs. Ploughing is done mainly to open the hard soil. In addition, ploughing should ensure inversion of soil, uprooting of weeds and stubbles and less cloddy soil surface. Wooden plough Mouldboard plough Disc plough, are used for this purpose.
Secondary Tillage: Lighter or finer operations performed on the soil after primary tillage are known as secondary tillage. Disc harrows, cultivators, blade harrows etc., are used for this purpose.
Layout of Seedbed and Sowing: After the seedbed preparation, the field is laid out properly for irrigation and sowing or planking seedlings. These operations are crop specific. For most of the crops like wheat, soybean, pearl millet, groundnut, castor etc., flat levelled seedbed is prepared. For some crops like maize, vegetables etc., the field has to be laid out into ridges and furrows. Sugarcane is planted in the furrows or trenches.
The tillage operations that are carried out in the standing crop are called after tillage. It includes drilling or side dressing of fertilizers, earthing up and Intercultivation. Earthing up is an operation carried out with country plough or ridge plough so as to form ridges at the base of the crop. Intercultivation is working blade harrows, rotary hoes etc., in between the crop rows so as to control weeds.
Fertilizers are applied by different methods mainly for three purposes: