Ruth Poglitsh wrote to us from Swaziland regarding EDN 82.“I wanted to let you know that I have really enjoyed EDN while I have been here. The feature on ways to improve your experimentation was excellent. And I was thinking about the Malian peanut sheller as I spent nearly eight hours shelling a backpack full of peanut pods. “On the alley cropping article, I had a couple of comments. When I was at the University of Florida, I was taught that alley cropping was not intended to be a way to increase yields/acre. The purpose was to shorten or eliminate fallow periods. It might be an appropriate tool if (1) farmers traditionally had long fallow periods for old fields (often around 7 years) and additionally (2) population pressures now made land a limiting factor and fields could not be fallowed for such long periods of time.
“Alley cropping would then allow the farmer to maintain a lower level of soil fertility over a long period of time. This situation fits very well with Dennis Shannon's data [reported in EDN 82]. At first the yields are less with the alleys. But the yields are more stable over time, hence reducing or eliminating the need to fallow the field.
“When I visited CATIE (Tropical Agricultural Research and Higher Education Center) in Costa Rica, I asked about their experience with alley cropping. They said that results were not promising because their soil was too fertile. Not a bad problem to have.
“It would be interesting to know if Dr. Sanchez would agree with this assessment or if the data suggests that even in this limited situation the competition with water makes other alternatives more appealing.”