Sustaining Row Crop and Fine Hardwood Productivity through Alley Cropping: On-Farm Demonstration, Research, and Economic Evaluation of an Integrated System
This project was undertaken to assess the feasibility of using alley cropping agroforestry in the North Central Region to 1) diversify farm incomes and produce needed timber for the wood products industries, 2) protect soil and water resources, and 3) reduce inputs to crop production.
Alley cropping agroforestry is the practice of planting crops or forages in alleys between rows of trees. Historical crop yields in existing alley cropping trials were used to establish research and economic objectives. Case study analyses of a private farm were also undertaken to determine feasibility of alley cropping as a sustainable system. Preliminary analysis in 1995 indicated that tree alleys were encroaching on crops in Purdue's 10 year-old trial. Environmental and physiological measurements also indicated that trees were competing for light and shading crops, lowering yields. This led to the implementation of treatments to separate trees and crops below ground to discern above and below-ground competition, as described last year. 1995 results showed that water competition below-ground was the major factor decreasing plant yields. This appears to have been replicated in 1996 though analyses are still underway. Given this knowledge, economic modeling has shown that management for below-ground competition (disking or knifing periodically to remove tree roots from crop alleys) significantly impacts crop yields and returns to the farmer for the alley cropping system. In many cases, alley cropping is more profitable than traditional farming of row crops. Different scenarios present different returns, but agroforestry, managed properly, can add value and lessen risk for farms.