[Application of bed planting systems in wheat] | Aplicaciones de sistemas de siembra en camellones para trigo

Wheat has traditionally been planted in solid stands, especially for both irrigated and moderate to high rainfall, dryland production systems. Wheat planting is usually accomplished by either drilling closely spaced rows 10-30 cm apart on the flat or by broadcasting the seed on a leveled soil surface followed by a shallow tillage operation for seed incorporation. These conventional wheat planting systems most likely represent a carryover from the rather random, scattered manner that wheat and other small grain cereals were first encountered and collected for food and ultimately domesticated through initial cultivation using crude hand tools followed by simple animal-drawn implements. In northwest Mexico (especially in the state of Sonora), researchers and farmers, have developed and implemented a fundamentally new system for planting wheat. Wheat in this part of Mexico is no longer planted as a conventional solid stand but on raised beds that are usually 70-90 cm wide upon which 2-3 rows of wheat are planted on top of the bed. The furrow or corrugation between the beds is used for irrigation water application. This planting system is quite different from the furrow-irrigated system occasionally found in some areas with irrigated wheat where the wheat seed is broadcast or drilled on the flat followed by the formation of the irrigation furrows or corrugations at approximately 90 cm intervals. With this system, the emerging wheat plants still remain in essentially a solid stand in the space between the irrigation furrows with many plants also emerging from the furrows themselves. However, this system does allow use of furrow irrigation instead of the more traditional flood irrigation providing better water management and drainage opportunities. The system used by farmers in northwest Mexico is quite unique in that the wheat is generally planted only on top of the raised beds and with a defined number of rows on each bed with a specific spacing between the rows . This paper will attempt to describe this system and the benefits that farmers in Mexico have attained through its application in irrigated wheat production areas and it will also present some results where wheat bed-planting has been used in rainfed areas where either too little and/or too much rain can occur during the growing season.