Transplanting method of rice is very popular and widely adopted in lowland irrigated areas.
This method is practiced for so many years. Transplanting method is time consuming because it involves the preparation of a seedling by sowing nursery in the prepared field. Direct seeding is increasingly practiced then the traditional method. This novel technology has been driven to solve the problems like increasing water shortage, labour cost and labour shortage for transplanting. One of the disadvantage of direct seeding as compared to transplanting is reduction in grain yield and grain size due to high weed infestation.
Transplanted rice is irrigated mostly with the fresh water in most of regions of the world that reduce water resources for human consumption. However, in last few decades due to climate change depletes water resources results in lowering the sustainability and productivity level of transplanted rice.
Recent reports indicate that in Asia, water scarcity is a major problem for transplanting rice in future. Transplanted rice require much quantity of water in different practices like puddling, surface evaporation and percolation. Puddling practice in transplanted rice consume one third of the total rice water quantity requirement.
Although, puddling is beneficial in rice wheat cropping systems, because it reduces soil permeability, creates hardpans and reduces water losses by the process of percolation. No doubt transplanting gave significantly higher yield as compared to different direct sowing methods, because it promotes tillering and control weeds.
Puddling also negatively effects on the crop in rotation by dismantling soil aggregates, reducing permeability in subsurface zone, and forming hardpans in subsurface zone. For saving water and labour and increasing the productivity level, direct seeded rice has been an alternate option for rice production to meets the need of food.
Direct seeded rice is a sustainable and very feasible alternative as compared to transplanting rice. It requires less quantity of irrigation water and demands less labour and ultimately reducing the total inputs. Direct seeded rice has received much attention because of its less inputs. Comparable rice yield in the direct seeded rice system and low input demand justifies the higher output to input ratio. The main problem faced by the growers is weed infestation in direct seeded rice.
Yield in direct seeded rice is often lower than transplanting rice principally owing to poor crop stand and high weed infestation. Moreover, cost for weed control is usually higher than transplanting rice. High weed infestation is a major constraint for broader adoption of direct seeded rice. But good weed management practices and use of weedicides at time will increase crop stand and yield. The method of direct seeding of rice is yet not clear around the world. Now a day some mechanical drills are designing for better and easy sowing.
The development of early maturing varieties in different countries and improved nutrient management techniques along with increased availability of chemical weed control methods has convinced many farmers in the world and also in Pakistan to adopt direct seeding culture. In future transplanting method can be replaced by direct seeding.
However, different agronomic aspects of direct seeding although well tried at different places in the world and are still to be investigated in detail against the transplanting method in Pakistan. This changing trend is helpful for the farmers to save their inputs cost and get maximum revenue to uplift their living standards.
This article is collectively authored by Ahmad Latif Virk , Naeem Ahmad, Muhammad Yousaf Nadeem, Saboor Khalid and Ghulam Hasan.