Crop Rotation for Riceby PR Sarkar
3 harvests: Rice + Peas and lentils
The rái and yellow but not the red varieties of mustard, khesári, the small black variety of peas, Bengal gram and lentils (the small variety) can all be sown as “pigeon crops” with paddy.
The rice is planted in Shrávańa, and then in the last week of Áshvina [[the “pigeon crop” is tossed into the field without tilling the soil or applying fertilizers.]]
After the rice has been harvested, the “pigeon crop” remains in the field until maturity.
When “pigeon crops” are grown, only 3 instead of 4 paddy crops can be harvested in a year, but mixed crops can be cultivated.
- For example, cow pea may be planted with áus in the month of Aśádha.
After the áus paddy has been harvested, the cow pea stands alone in the field because it has a maturing period of 9 months. During this period a second associate crop should be sown, preferably a fibre crop.
In such cases, the field will not yield 4 crops of paddy in a year.
Other crops such as green gram, radish, onion and in certain seasons pisciculture do not interfere with 4 paddy harvests in a year.
4 harvests: Rice + Peas and lentils
The system for reaping 4 crops of rice per year is as follows.
All varieties of paddy should stay in the nursery 1 month, or 1.5 months in unusual circumstances. They are then transplanted as seedlings and stay 2.5 or 3 months in the field.
The following system should be used for planting paddy:
- Half of Vaeshákha, Jyaeśt́ha, Aśáŕha and half of Shrávańa – áus paddy.
Plough the field six times in water by tractor. Plough four times in the first two days – two times the first day, two times the second day. Leave the field submerged in water for 8 more days.
Add organic fertilizers and compost. Plough again 2 more times.
On the last ploughing use NPK (nitrogen, potassium and phosphate) fertilizers if appropriate.
While growing áus paddy, the soil should be wet but not waterlogged. Between every two áus plants, one rainy season radish should be sown.
Radish may be sown in the áus field for the entire period. In a transplanted áus field, a “pigeon crop” of green gram may be sown. There should be no accumulation of water in the áus field – water should be able to move freely in and out of the field. Green gram is grown for the second two months. Of all the seasonal varieties of rice, áus paddy gives the lowest yield.
In the first week of Shrávańa the áus is harvested. Plough and fertilize the field again as above to prepare for the next crop.
- Half of Shrávańa, Bhádra, Áshvina and half of Kárttika – áman paddy.
No mixed crops can be grown with áman paddy but pisciculture may be cultivated. These fish can be a good animal food for carnivores. Fish such as charamach, koira, guri and rai mach may be produced – that is, small fish, crabs and prawns. For the production of rui or larger fish, a big pond is needed.
During the production of áman paddy there should always be a lot of water in the field. Of all the seasonal varieties of rice, áman paddy gives the highest yield. Its straw is also long and very useful in making mats and other products.
One month before the harvest in Áshvina, the seedlings of early boro paddy should be started. After the harvest, the field should again be prepared as above.
- Half of Kárttika, Agraháyańa, Paośa and half of Mágha – early boro paddy.
There should always be water in the field until the time of harvesting. If there is less rain, big onions or garlic can be planted between two early boro paddy plants. These big onions are the sprouted small onion (chachi piaz or sachi piaz) of the previous period. If there is more rain, pisciculture may be cultivated in the early boro field. In the first week of Mágha, the early boro paddy should be harvested.
Special care must be taken to acquire a big onion type which is a winter crop as they need less water. Green gram requires less water than onions. No “pigeon crop” can be grown with áman paddy because there is too much water in the field.
At this time the big onion seeds are not ready and the small onions cannot be planted under so much water. Care must be taken to ensure that the variety of onion used in the early boro field is the type that always remains above water. Onions need water, being 67% water themselves, but they cannot be inundated.
If irrigation water is not available after áman paddy, then the boro paddy should not be sown, but “pigeon crops” may be sown.
Except for áman paddy, there can be “pigeon crops” in every season. After the harvest, the field should again be prepared and fertilizers applied as above.
Boro paddy gives a medium yield compared to the other seasonal varieties of rice. The straw is fairly long, but animals do not like it. Green gram can be grown as a “pigeon crop” in the second two months of the early boro or late boro rotations.
- Half of Mágha, Phálguna, Caetra and half of Vaeshákha – late boro paddy.
Late boro is transplanted by the 15th of Mágha. Between every two boro plants, one small onion (chachi piaz) should be planted. Small onion is obtained from the seeds of big onion (boro piaz). Small onion takes four to five months to grow and should be developed in the nursery for the first one or two months before being transplanted.
Seeds from the big onions are used to produce small onions, and the onion tubers (kalik) from small onions are used to produce big onions. Big onions are used both as a vegetable and for seed production. If the big onions are to be harvested for marketing, then the stalk should be twisted down while it is green and about to flower. If this is done the onion grows to its maximum size.
Kusum flower can be planted as a boundary plant around the late boro field and can also be harvested. If there is enough water, pisciculture may be practiced with late boro and hot small onions.
All paddy requires clay soil. Where there is water in the field, care must be taken to ensure that the heads of the paddy stalks are not submerged.