The transformation of agriculture in Brazil through development and adoption of Zero Tillage Conservation Agriculture

The soil conservation movement in Brazil has been a major driving force in the continuing search for agricultural farming systems that are more sustainable than what we have today,particularly in tropical and subtropical areas.The development and adoption of Zero Tillage Conservation Agriculture(ZT/CA)was the key to the success of this movement,generating agricultural,environmental,and societal benefits.Adoption of the ZT/CA philosophy and technologies is currently practiced on more than 50%of the annual crop area.This is due to the work and innovations of pioneering farmers,agronomists,researchers,and consultants that were and are involved in these efforts.This extensive adoption of ZT/CA occurred after many unsuccessful efforts to mitigate against the devastating effects of soil erosion that were threatening the entire agricultural industry in Brazil.Technicians and farmers realized that erosion control required continual cover of the soil to guard against the torrential rain storms common to these regions.This triggered the efforts of soil conservation pioneers at different points in time and regions of Brazil.In southern Brazil,Herbert Bartz,watched his topsoil eroding away in torrents of runoff.This set him thinking and searching for alternatives,resulting in his adoption of ZT/CA farming in 1972.Ten years later in Brazil’s centre-western savannah(Cerrado biome),farmers,researchers,crop consultants and agro-industry initiated efforts to expand cultivation into the very difficult production region of the Cerrados.This was successfully achieved through the pioneering work of agronomist John Landers,bringing experience from the ZT/CA farmer association networks in the south.These were the turning points in the sustainable development of annual crop farming in Brazil.Today,society recognizes the role of these pioneers as key to achieving social,economic and environmental sustainability.ZT/CA reversed the historically accelerating degradation of soil organic matter and soil structure by abandoning conventional tillage,thus improving soil physical and chemical characteristics.This was achieved by promoting cover cropping and permanent soil cover with crop residues,crop rotations,and complementary,environmentally suitable soil management technologies.

The development and adoption of conservation tillage systems on the Canadian Prairies

One of the major agricultural innovations on the Canadian Prairies over the last 40 years has been the introduction of conservation tillage(CT).Conservation tillage-a system that includes minimum and zero tillage(ZT)-was introduced as an alternative to traditional(conventional)tillage(TT)to control soil degradation and to promote agricultural sustainability.The development and adoption of CT systems involved pioneer farmers,engineers,scientists,and farmer associations.By the end of the 1970s,CT started to take shape on the Prairies,but for a number of economic,technical,political and social reasons,the adoption of CT did not occur on any major scale before the 1990s.Today,more than 75%of the Prairie’s cropland is under some form of CT with more than 50%under ZT.In this paper,the factors behind the development and adoption of conservation tillage technology on the Prairies in the period between 1930 and 2011 are reviewed.Then,some of the benefits of the adoption of CT on the Prairies are highlighted.The data show that CT and ZT became profitable for the majority of farmers during and after the 1990s,and that the increased use of CT contributed to the dramatic decrease in the area under summerfallow and to the increase in the area sown to canola and pulse crops.These changes contributed to the reduction of all forms of land degradation and to decreases in agricultural greenhouse gas(GHG)emissions.

Current status of adoption of no-till farming in the world and some of its main benefits

In 1999 no-tillage farming,synonymous of zero tillage farming or conservation agriculture,was adopted on about 45 million ha world wide,growing to 72 million ha in 2003 and to 111 million ha in 2009,corresponding to an growth rate of 6 million ha per annum.Fastest adoption rates have been experienced in South America where some countries are using no-tillage farming on about 70%of the total cultivated area.Opposite to countries like the USA where often fields under no-tillage farming are tilled every now and then,more than two thirds of the area under no-tillage systems in South America is permanently not tilled;in other words once adopted,the soil is never tilled again.The spread of no-tillage systems on more than 110 million ha world-wide shows the great adaptability of the systems to all kinds of climates,soils and cropping conditions.No-tillage is now being practiced from the artic circle over the tropics to about 50ºlatitude south,from sea level to 3,000 m altitude,from extremely rainy areas with 2,500 mm a year to extremely dry conditions with 250 mm a year.No-till farming offers a way of optimizing productivity and ecosystem services,offering a wide range of economic,environmental and social benefits to the producer and to the society.At the same time,no-till farming is enabling agriculture to respond to some of the global challenges associated with climate change,land and environmental degradation,and increasing cost of food,energy and production inputs.The wide recognition of no-till farming as a truly sustainable system should ensure the spread of the no-till technology and the associated practices of organic soil cover and crop rotation,as soon as the barriers to its adoption have been overcome,to areas where adoption is currently still low.The widespread adoption globally also shows that no-tillage farming cannot any more be considered a temporary fashion or a craze;instead largely through farmers’own effort,the system has established itself as a farming practice and a different way of thinking about sustainable agro-ecosystem management that can no longer be ignored by scientists,academics,extension workers,farmers at large as well as equipment and machine manufacturers and politicians.

Conservation agriculture in India-Problems,prospects and policy issues

Conservation agriculture(CA)technologies involve minimum soil disturbance,permanent soil cover through crop residues or cover crops,and crop rotations for achieving higher productivity.In India,efforts to develop,refine and disseminate conservation-based agricultural technologies have been underway for nearly two decades and made significant progress since then even though there are several constraints that affect adoption of CA.Particularly,tremendous efforts have been made on no-till in wheat under a rice-wheat rotation in the Indo-Gangetic plains.There are more payoffs than tradeoffs for adoption of CA but the equilibrium among the two was understood by both adopters and promoters.The technologies of CA provide opportunities to reduce the cost of production,save water and nutrients,increase yields,increase crop diversification,improve efficient use of resources,and benefit the environment.However,there are still constraints for promotion of CA technologies,such as lack of appropriate seeders especially for small and medium scale farmers,competition of crop residues between CA use and livestock feeding,burning of crop residues,availability of skilled and scientific manpower and overcoming the bias or mindset about tillage.The need to develop the policy frame and strategies is urgent to promote CA in the region.This article reviews the emerging concerns due to continuous adoption of conventional agriculture systems,and analyses the constraints,prospects,policy issues and research needs for conservation agriculture in India.