Cultivation of one particular crop in the same plot of land for many years depletes the soil of certain nutrients from the same layer of the soil profile and create an unbalanced situation on part of nutrient with other soil layer, also helps in building up pathogen and pests.
To overcome such situation, crop rotation, a method, maintaining a sequence of cultivation of different type of crops in a same agricultural plot of land , helps in reducing soil erosion , improve soil structure and increase in soil fertility by increasing bio mass from varied root structure.
Inclusion of legumes and green manuring crops along with principal crops is an important aspect with regards to crop rotation.
Legume crops ( Black gram, Green gram, Pea, Cowpea, Lentil etc.) possesses nodules on their roots which contain nitrogen fixing bacteria with a capability of accumulating atmospheric nitrogen which in turn converted into an organic compound that the plant can convert as its nitrogen sources. Provision of a legume crop in the crop rotation should always precede with a crop which deplete nitrogen from soil and also use a combination of a low residue crop with high biomass. On the other hand green manure crops when incorporated with soil act as a source of nitrogen. Soil micro-organisms also help in reducing pest and pathogens through competition.
In the process of crop rotation, covered vegetation competes with other unwanted plants for soil space also with plant nutrient. On the other hand , uncollected roots of crops after harvest breaks down, making the stored nitrogen available to future crops. The use of different species in rotation increases soil organic matter (SOM). With more SOM, water infiltration and retention capacity improves, providing increased drought tolerance and decreased erosion.
This process also helps in increasing beneficial effect on the natural ecosystem comprising various flora and fauna of the nature.
Other benefits :
Pest control: The changing of crops in a sequence way, decreases the population level of pests by interrupting both pests’ life cycles as well as pest habitat. Same type of plants tend to have similar pests and pathogens. By regularly changing crops in an alternative way, pest cycles can be broken or turn to a commendable limit.
Soil erosion: In this process, left over of plant residues of crops after harvest ultimately protect the soil from being washed away by various factors such as wind, water etc.
Farm productivity: Crop rotation thus contribute to raise the farm income through utilizing the agricultural land in an efficient way, also it helps in proper engagement of labour of a farm family in an effective way. Besides, benefits of rotation of cropping systems include production cost advantages and financial risks are more widely distributed over more diverse production of crops.
In addition to boosting of crop productivity, crop rotation has great implications in reducing carbon dioxide from the air.
For better and efficient use of soil, effective utilization of farm labour of a farm family, it is utmost necessary to have a handy and pragmatic approach through a properly planned cropping pattern for crop rotation programme for a particular plot of land.
(SHRI BHUPEN DUTTA. M.Sc.Agri.)