Diversification of farms: Rotations, except in the case of an alternate grain-fallow system, provide some diversification of crops. Diversification may assure more economical use of irrigation water as well as’ other facilities. The risk of complete failure due to weather, pests, and low prices is less with several crops than with one. Crops may be selected so as to spread labor throughout the year.
Control of weeds, insects and diseases: The rotation of crops is one of the best mea!1s of controlling weeds. With each crop appear certain typical weeds, and increase rapidly if a crop is grown continuously but can frequently be checked by change of crop. Crops like potato and fodders like berseem when included in rotation exert, a smothering influence. Similarly, many insects trouble only one crop or one group of crops. Also” there are many diseases that injure one crop but are not harmful to other crops. So, changing crops is an effective method of checking damage from insects and diseases.
Maintenance of organic matter: As the grasses, clovers and green manuring crops are included in the crop rotation programme, these crops usually increase the supply of organic matter to the soil.
Addition of nitrogen: The legumes not only increase the supply of organic matter but also help to maintain the nitrogen supply of the soil.
Protection of soil against erosion: The areas where there are heavy rains and strong blowing winds, and there is only single cropping system, wind erosion as well as water erosion will result in heavy losses of plant nutrients and soil, unless the soil is adequately protected with growing vegetation or crop. So under such conditions a crop rotation programme will keep the soil
busy and so will save it from erosion.
Alternation of crops: Rotation provides the alternation of deep and shallow rooted crops and thus allows for a more complete use of the soil. Potato, tobacco and small grains are shallow rooted crops. Such crops deplete the surface soil. If alteration of crops is followed, a balanced amount of different nutrients is removed by the plants.
Farming is systematized: The rotation of crops helps to engage the farm labour throughout the year and also enables the farmer to estimate ahead of time about labour, quantity of seed, and power and machinery necessary for farm operations.
Soil Reclamation: The soils which are affected by waterlogging and salinity can be reclaimed by including some special grasses in the rotation.
Increase in water use efficiency: Rotation of crops usually increases crop yields. Therefore, the’ water use efficiency is increased. Moreover, the available water resources are utilized in a better way.
Key Referene : General agriculture By Muhammad Akhtar Abbas
