Progressive No-Tillers in Latin America have discovered that green manure cover crops are the cornerstone of sustainable agriculture and are always included in any sound no-till crop rotation, says Rolf Derpsch.

While the climates in Latin American countries differ from those of most U.S. crop-producing areas, there are basic cover crop and crop-rotation principles that you can adapt to enhance weed control, reduce herbicide costs and slow the development of herbicide resistance worries.

Derpsch is an agronomist who specializes in no-tillage systems and the development of sustainable production systems with green manure cover crops and crop rotations. Prior to becoming an independent consultant last year, he worked for the German Agency for Technical Cooperation (GTZ) from 1966 to 2001. Between 1993 and 2001 in Paraguay, he served as senior advisor to the MAG-GTZ Soil Conservation Project, a joint venture between GTZ and the Ministry of Agriculture and Livestock in Paraguay.

The agronomist has been studying the effects of cover crops and crop rotations on weeds. In recent tests, he no-tilled soybeans after a black oat cover crop and achieved a 39-bushel-per-acre soybean yield without any herbicides.

Needs No-Till Systems Approach

Derpsch suggests there are fundamental principles that should be followed to achieve these results. First, cover crops and crop rotations are not mutually exclusive.

“You can’t think of cover crops without thinking about crop rotation. A cover crop is nothing without being inserted into a crop rotation,” says Derpsch.

Effective crop rotation is a must with no-till, maintains the agronomist…