A discussion article by John Landers, a TAA member based in Brazil, with extensive experience of zero tillage, was published in Agriculture for Development 35. As John says: “ I believe Zt rice/wheat to be at take-off stage in the Indo-Gangetic plains. But even more important, I flagged here the albedo effect of rice straw – this cooling effect of increased albedo has been totally sidelined in the debate on Global Warming. The impact of 100% ZT Rice/Wheat could be HUGE if adopted widely in the sub-continent. It would significantly reduce globsl warming, cut irrigation water demand and improve yields. It is a win-win-win scenario waiting to be unveiled”.
The rice–wheat succession predominates on the Indo-Gangetic plains, zero-tillage wheat is now widely adopted and second-generation zero-tillage seed drills are in general use. But, the traditional, water-intensive and high-cost method of rice puddling and transplanting is still almost ubiquitous. New zero-tillage rice technologies have recently been successfully developed by scientists from India, the Maize and Wheat Improvement Center (CIMMYT) and the International Rice Research Institute (IRRI), to substitute the traditional technology for a system using zero tillage in both crops. This paper concentrates on recent results for direct- seeded rice as the most common alternative to puddling, while non-puddled transplanting and direct seeding of pre-germinated rice seed have also had some success. Although yield results have not been consistent for direct-seeded zero- tillage rice, there is consensus on significant water and labour savings and improved incomes.
A list of 15 potential benefits for direct-seeded zero-tillage rice is presented, with a discussion of the facts behind the topics of puddling, non-puddling innovations, weed control, water use and aquifer recharge, soil physical parameters, profitability, improved rotations, labour demands, zero-tillage impacts on the System of Rice Intensification and climate change. A fact summary table facilitates the evaluation of different factors in the elimination of puddling in rice. Recommendations are made on research topics that need to be addressed in direct-seeded rice, especially better weed control, improved upland rice varieties, the extent of aquifer recharge and the straw albedo effect in climate change. A risk assessment evaluation for resource-poor farmers is needed and also an evaluation of the willingness of service providers to make investments in new machinery. Social transfer payments for water saving and more sustainable farming practices are suggested. It is noted that zero population growth is essential to our planet’s sustainability, which will also be threatened by the increasing demands of improved wealth distribution from the Millennium Development Goals. More efficient agriculture and resource use in a stable world population are key to future planetary vitality.
Reference: Landers JN. 2018. Discussion paper on eliminating puddling in rice by using zero tillage.Agriculture for Development,35 (2018) pp 23-30.