Transplanting rice is perhaps the most elaborate method of cultivation in the country. As its name implies the seed is sown in one place and the seedlings after they have grown a little are transplanted to another. This is done in order to get higher yields and less weeding. Below are given some of the methods used for rice transplantation with their shortcomings:
It is labor intensive and requires 250-350 man-hr per hectare that is 25 % of the total labour requirement of the crop.
It fails to meet the agronomical requirements like plant population per square meter and uniform row and hill spacing, thereby limiting the use of agricultural implements and hand tools for intercultural operations.
It consumes more time in transplanting and also involves a lot of human drudgery.
Self propelled Rice Transplanter Machine
It has the problems of poor traction, sinkage and steerability.
It works on puddled soil; it encounters a hard surface at plow pan and a soft puddled soil at the top where it must also have sufficient bearing capacity to prevent sinkage of the float. At the same time the plow pan must not be too deep to provide necessary thrust to propel the transplanter. Both traction and bearing capacity are dependent upon shear strength of the soil. Usually a transplanter would be immobilized either by failure in bearing or traction.
Efficient working of a self-propelled rice transplanter requires a suitable puddled soil condition vis-à-vis optimum depth of puddling, degree of puddling and soil strength of puddled field. High degree of puddling severely affects the mobility
But Long-term experiments suggest that continued puddling for rice destroys soil physical properties and affects both the puddled rice yield and the following crop negatively.
Advantages of puddling:
Reduces soil permeability
Preserves aquatic, anaerobic conditions
Controls weeds, improves water and nutrient availability
Disadvantages of puddling:
Destroys soil aggregates
Breaks capillary pores
Disperses fine clay particles
Lowers soil strength in the puddled layer
Plough pan (compacted layer) resists root penetration of following crop
Can cause water logging
Forms large clods in finer textured soils preventing seed-soil contact
Forms impermeable clayey layer on the surface in coarser soil
So you have to come up with an alternative method of transplanting rice or suggest methods for correcting the disadvantages of the above mentioned procedures of plantation that require less labour and water without sacrificing productivity. The alternative method should be able free from the shortcomings mentioned above in other methods.