Crop RotationJanuary 31, 2022
In crop rotation, the soil is under cultivation for most of the year.
In the Purulia district of West Bengal, many farmers grow only one crop of paddy a year. Through crop rotation, 4 crops can be harvested in a year.
In the rainy season, no mixed crop can be grown with paddy, only small fish.
Autumn paddy can be combined with big onions, summer paddy with radish, and spring paddy with small onions grown from seeds.
The 2 main principles of crop rotation are:
- Maximum crops should be planted in the minimum period of time
- Maximum crops should be planted in the minimum space.
These should be implemented without affecting soil fertility.
An example of the first principle is reaping four crops of rice in a year where there was only one, two or three before. For instance:
- In Vaeshákha transplanted áus or summer paddy can be planted and in Shrávańa it can be harvested.
- In Shrávańa transplanted áman or rainy season paddy can be planted and in Kárttika it can be harvested.
- In Kárttika early boro or autumn paddy can be planted and in Mágha it can be harvested.
- In Mágha late boro or spring paddy can be planted and in Vaeshákha it can be harvested.
In central Ráŕh there are only four months of rain. For the rest of the year there is little or no rain, yet it is still possible to get four crops a year.
For example, with áus paddy, radish should be planted between the rows of rice. With áman paddy, small fish but no crops should be cultivated. The fish maintain the water level in the field and can be caught by carnivorous humans or animals, or left in the field to fertilize the soil after the water has dried up.
With early boro paddy, big onion and safflower as a boundary plant should be cultivated. With late boro paddy, onion seeds which produce onion bulbs should be planted as a subsidiary crop.
A special system is used to grow rice in 2.5-3 months instead of 4.
Early in the year, transplanted áus seedlings should be grown. Áus takes 4 months before it is ready for harvesting, so for the first 4 weeks, the áus seedlings should be kept in a nursery. For the remaining 2.5-3 months, they should be grown in the field.
The period for áus is Vaeshákha, Jyeśthá Aśádha and Shrávana.
In between the áus seedlings, radish can be grown.
A good variety of oil which is a substitute for mustard oil can be produced from the seeds of radish. The radish should be of the summer variety. The leaves of radish are very good for the liver.
After áus, áman variety of paddy can be grown according to the same system used for áus – that is, 1 month in the nursery and 2.5-3 months in the field.
The áman paddy should be in the nursery while the áus crop is in the fields. The period for áman is Shrávańá, Bhádra, Áshvina and Kárttika. There cannot be any blended crop with áman, but instead pisciculture can be practised. During áman cultivation some fertilizer may be necessary, but whatever fertilizer is used should be non-poisonous, otherwise it will kill the fish.
In Ráŕh, the soil is of a sticky nature so it does not allow water to seep underground. This type of soil is very good for áman cultivation. Ráŕh has the best soil for áman cultivation in the entire world.
After áman we have to cultivate the early variety of boro according to the same system. With boro, onion and garlic can be grown as blended crops between the seedlings. Around the boundary of the field, one line of safflower seeds can be grown. Oil which has medicinal value can be produced from the seeds of onion.
After early boro, late boro paddy should be cultivated following the same system. As a blended crop in between the seedings, transplanted onion can be grown. Onion is static so Ánanda Márgiis should not take it. However, onion leaves are mutative in the daytime, not at night, so householders can eat them.
So according to this crop rotation system, fields will be occupied for two and a half to three months each by four crops a year, totalling ten or eleven months. For the remaining period, the fields should be prepared for the next rotation. This is an example of how to get maximum crops in minimum period of time.
This type of paddy rotation system is best for sticky or clay soil.
If the soil is half sandy half sticky alluvial soil, barely two paddy crops – áus and amam – can be grown. Wheat and mustard can be cultivated the rest of the year. Planting 20% mustard with wheat will increase the production of wheat by 150%. Peas or lentils can also be grown with the wheat.
Two potato crops can be grown in a season:
- 60 days or early potato
- 90 days or late potato
60-day potato is produced for immediate consumption. It cannot be stored because it is not fully matured, but the 90 day crop can be stored.
Both varieties can be dried, powdered and then stored. 60 day potato grows in the months of Áshvina and Kárttika, while 90 day potato or mature potato grows in the months of Agraháyańa, Pauśa and Mágha. With 90 day potato different types of spices can be grown, such as coriander, cumin and chandani. Cauliflower and pumpkin can also be grown. If potato is grown in the mounds of a ploughed field, brinjal can be grown in the furrows from cuttings, as it needs more water. The winter variety of chilli can also be grown.
The second principle of crop rotation is growing maximum crops in the minimum space.
An example is growing potato in mounds in rows with a cauliflower between each potato as a surface crop.
The potatoes are root crops. So no competing root crop, such as peanut, should be grown at the same time.
On the slopes of the mounds small spices like cumin can be planted. After one month when the potatoes have partly grown, canals for irrigation should be dug between the rows of potatoes. In the canals brinjal, cucumber and chilli can be planted. Cauliflower matures before potato. When it matures it can be cut, but the roots should be left in the soil so as not to disturb the potato crop.
Another example is wheat.
20% mustard can be planted with 80% wheat. Mustard grows leaves which can be used as a vegetable and seeds which can be pressed to produce oil. If mustard oil cake is put in water until it starts giving off a bad smell, and is then mixed with more water and spread on the fields, it makes a good fertilizer. Bees can also utilize the flowers to make excellent honey.
In addition, on the border of the field two rows of garlic should be grown so that their spacing is in the configuration of equilateral triangles.
In the middle of each triangle, one safflower seed should be sown to make another row of safflower flowers. So, four crops can be grown: wheat, mustard, garlic and safflower. Other crops also can be grown as blended crops.
For very infertile soil, barley rotation can be grown with a supplementary crop. For example, 20% of the area reserved for the barley crop can be planted with red mustard. If one is going to cultivate sugar cane, banana or radish, the seeds, cuttings or roots should be brought from at least twelve miles away. However, they may come from the opposite bank of a river which is less than twelve miles away.
The brinjal plant should have thorns, as the thorny brinjal produces tasty brinjal. White brinjal should not be cultivated because it is static and makes the soil infertile.
When cultivating lentils, high quality manure should be used, and the best manure for this purpose is the oil cake of castor. Lentils crops should not be discontinued simply because they need good fertilizer, because they can be used to produce refined vegetable oil and lubricants.
Linseed can also be used to manufacture refined vegetable oil and lubricants, as well as scented hair oil, linen cloth, etc. Linseed can be cultivated after lentils. When there is a scant supply of water, a “pigeon crop”(1) of the rái variety of mustard can be grown.
The mustard seeds should be spread out over the whole field while it is still wet after the rainy season, then the crop will grow through the dry season.
It is not economical to cultivate sugar cane in Bengal because it occupies the land for a whole year. Sugar beet should be grown instead, because three crops can be grown in a year.
However, sugar beet cannot supply molasses, which is a very famous food in rural Bengal. Also, seeds cannot be produced from sugar beet due to the hot climate, so they have to be imported from outside the region. Research should be done to develop varieties of sugar beet which produce seeds in warm climates.