Evaristo Eduardo de Miranda
Zero-Tillage Evolution In Brazil
1 – Introduction
Zero-Tillage (ZT) based agriculture has been practiced for the past thirty years in Brazil, but it has showed a dramatic increase in area over the last decade, reflecting a deep behavioral change in farmers and technicians. ZT provides an effective control of land degradation, reducing soil erosion, and increasing efficiency, productivity, and soil organic matter. An added benefit is a substantial improvement in environmental quality due to the sustainable use and management of natural resources and the rationalization of agricultural input application.
Since the first experiences with the ZT system were initiated in the seventies, it has undergone many tests and studies. The useful technological integration among innovative farmers, research institutes, input and machinery industries, official and private technical assistance and agricultural related services have managed to overcome many difficulties. Thus building a solid base of knowledge and reference.
Through ZT´s initiative there has been a behavioral change among producers and technicians towards sustainable agriculture. This process has resulted in a greater professionalism through the incorporation of new technologies and the improvement of managerial factors in the production process. Therefore resulting today in a recognized alternative for establishing policies which favor sustainable environmental development. This has evident benefits for society as a whole.
The increase from around l million hectares of annual cultures (early 90s) to 12 million, in the year 2000, has made ZT stand out in Brazil. Besides, the system has also been utilized in all perennial cultures: sugarcane, recovery of pastures through rotation with farming, reforestation, orchards, vegetable farming etc. ZT has revealed itself as the most potent instrument to be developed in the rational manipulation of water basins, given its broadness and universality.
Hoping this exceptional expansion may bring desirable benefits, there is an opportunity for partnerships with a variety of commitments e.g. the “Friends of the Land Clubs (CATs)”, cooperatives , associations, foundations, groups and etc. The aim of these organizations is to develop a cleaner and prosperous agricultural development which in turn will open itself to new fields of cooperation in research/education and obtain a better balance in the Brazilian agribusiness.
ZT is made up of a group of integrated techniques with the aim to improve the environmental conditions (water, soil, climate) and to explore, in the best manner, the potential of the natural resources available inside the agro-ecosystems. In this process three minimum requisites should be considered: the soil not being revolved, rotation of cultures and using hay for covering the plantation (mulching). It can be associated with the integrated control of pests, diseases and weeds. However, ZT should not be taken as a universal recipe but as a system that requires local adaptations. Farmers have taken the initiative through a continuous integration effort of with soil scientists and technicians, what made it possible the advance in the development and transfer of technologies.
Adopting ZT adds values soils as a multifunctional environmental compartment and results in significant savings to society as a whole. It minimizes the costs per produced unit by maximizing the productivity of labor and the efficiency in the use of industrial. It also increases the process of carbon sinking through the accumulation of organic matter in the soil.
ZT in Brazilian agriculture has improved the professional capacity of hand labor and the managerial skills in agricultural activity and increased the productive efficiency and income of the sector. This have had multiplying effects in the secondary and tertiary sectors of the economy by creating more employment. The agribusiness as a whole has obtained greater economical, social, and environmental sustainability. The presently 12 million hectares under zero- till practices is represents one third of the total annual culture cultivated in the different areas of the country.
2 – Environmental impact assessment of zero-tillage
The environmental and social benefits of ZT practices can be summarized as follows:
Reduction by 90% of a gully erosion which can reach up to a hundred tons of fertile earth per year, so preventing rivers, lakes, and dams from siltation and improving the quality of drinking water;
Contributing to the rational handling of the water basins by preventing obstruction of rivers, lakes, lagoons, and dams. Thus resulting in positive reflexes and improving the quality of water, irrigation availability, and human and animal consumption other than reducing floods;
Adding to the maintenance of biodiversity;
Decrease in the emission of gases that interfere with the green house effect thanks to the reduction in the usage of fossil fuel up to 60-70%;
Carbon sinking effect through the absorption of about a hundred and thirty million tons of atmospheric carbon for each 1% of increase in the superficial layer (20cm) of the soil’s organic matter in the 12 million hectares of area under the ZT in Brazil. In potential terms, these figures generate and gather compensatory credits of more than l billion dollars per year considering the viability of the carbon market;
Significant reduction in agricultural risk because of a greater probability to follows the proposed agricultural zoning calendar. This attracts the insurance sector offering better actuarial calculations and granting the implementation of professional insurance, articulation of funds and equalization of premiums against catastrophes. This will be carried out with the Government’s participation creating positive results, greater stability and permanence with the producers using ZT;
ZT has the potential for use in all activities and by all producers who are in favor of employment and income. ZT facilitates diversification of activities regarding family agriculture because of the reduction in chores which demand a large amount of hand labor (preparing soil and tract of land). Therefore, income improves and there is a reduction of rural migration to urban zones.
The system simplifies the agricultural calendar, validating zoning recommendations and making it attractive to the insurance companies and establishing viability in agriculture. Farming and cattle raising research in this country has proven ZT as on of the most important Brazilian environmental action. This satisfies the recommendations of the United Nations Eco-92 conference and the Brazilian “Agenda 21” as was agreed upon in the Green Protocol.
3 – Cooperative research and development in Zero-Till Agriculture in Brazil
Initial research and farmer-developed practices have contributed to the rapid expansion of ZT adoption. However, a second generation of problems in plant diseases, insect and weed pests as well as agronomic difficulties in some situations have sometimes hindered its expansion. In addition, because of different climatic, soil and agronomic conditions, many local adaptations to technologies have been required. The cooperation between farmers, researchers, university lecturers and professors, private corporations, and extension personnel is necessary to identify setbacks to ZT and determine the particularities of specific regions, which will help the identification of problems and existing solutions in order to overcome present and potential limitations.
In order to identify limitations to ZT expansion, a project was executed providing a technology platform for future research for scientific and technical solutions. The goal of the Platform Project is to prioritize Research and Development (R&D) actions based on the problems and solutions identified by stakeholders. The prioritization of R&D will help to prepare a solid basis as support to promote ecologically and socio-economically sustainable development, globally competitive as well as socially fair, giving definitive support to Brazilian agriculture.
Financial support for the Platform Project comes from the national plan for supporting scientific and technological development (PADCT/CNPq). Different key players have assisted in organizing the project, including the Brazilian Federation for Zero-Till into Crop Residues (FEBRAPDP – proposer), the Brazilian Agricultural Research Enterprise (Embrapa – executer). In addition, the close partnership of universities, state research and extension agencies, Friends of the Land Clubs, agricultural research support foundations, associations and agribusiness is involved in the organization of this Technology Platform. Three activities have being been carried out:
(i) the gathering of information and prioritization of problems/limitations to ZT performance and farmers’ alternative solutions in all agricultural activities, using a rapid participatory appraisal methodology, especially adapted for application with farmers throughout Brazil. ZT problems, prioritized by farmers, taking in consideration the frequency of occurrence, weight of the problem, and the difficulty of finding solutions, may drive new projects in cooperating R & D institutions. In addition, farmers were asked to indicate solutions and actions, based on their field experiences. Simultaneously, a survey of scientific and technological references has catalogued on-going projects, classifying researchers on a web. The cross-checking of problems, solutions, actions and available technologies will help to formulate a list of subjects for R & D cooperative projects, as well as a catalogue of available ZT technologies for tropical and subtropical regions.
(ii) a survey of the present situation of ZT-related technological training and extension, allowing us to demonstrate how technologies are reaching farmers. Involved participants include university lecturers and professors, extensionists, and technical field personnel from both small-scale private companies as well as large multinational ones.
(iii) the consideration of a legislative and policy component which will seek to highlight the environmental and social benefits of ZT for both the rural and urban population of Brazil. This partnership effort, lead by Embrapa, has elected to return to farmers the responsibility of defining ZT research and development priorities, focusing their real problems and proposed solutions. This platform could serve as an excellent policy tool for Brazil, as well as other tropical and sub-tropical countries, showing how to identify and create practices and policies to guarantee the sustainability of agriculture, based upon the participation of farmers as well as other key stakeholders. Thus the solutions proposed are not based solely on the perspectives of researchers and policy makers, but on those of farmers as well, who are key players in understanding and implementing these solutions.
5 – Main Sources