A history of tillage in California’s Central Valley

Abstract The Central Valley (CV) of California is a remarkably productive agricultural region. Much of the productive capacity of the CV stems from the reliable tillage management systems that were developed beginning in the 1930s and that changed very little until the 1990s and even more dramatically in the 2000s. A variety of technologies, people and social networks have contributed to the major transformations in tillage management that have rapidly occurred during this recent time. Factors that influenced the prior slow evolution of tillage systems in the region include the need to find ways to farm with irrigation, cope with a broad range of soils, achieve high crop quality and yields to compete on world markets, expand farming operations to greater acreage, and find ways to farm with ever-increasing costs. The cost increases, recognition of the emerging concepts of conservation agriculture (CA), and the development and broader adoption of advanced irrigation systems are now spurring farmers and research organizations in the CV to overcome problems experienced with conventional tillage practices and to develop new cropping systems in the region including no-tillage and strip-tillage. Ultimately, broader adoption of conservation agriculture principles and practices in this region will stem from a diverse and complex set of motivating factors. The role of global farmer-to-farmer communication has had a major impact on this process. Ongoing targeted problem-solving efforts addressing weed, water and fertility management in conservation agriculture systems will be needed to make them more reliable and widely used.