Published

2015-04-06

Two new field experiments are being established this month at ECHO’s Global Demonstration Farm in southwest Florida. Both studies involve tropical legumes, which provide farmers with a source of green manure, grain, and/or animal fodder.

The first trial will shed light on how much moringa (Moringa oleifera) leaf powder can be expected with various soil amendments and the intercropping of a tropical legume. The soil amendments include a no-input control, biochar, compost, and biochar + compost. The idea behind the biochar + compost treatment is to load the pore spaces in biochar particles with both microbes and nutrients. Once the moringa trees are approximately knee height, we plan to sow a bush variety of velvet bean (Mucuna pruriens) at the base of half of the moringa tree rows. This will allow us to test the effect of soil amendments on moringa growth and leaf production, with and without a tropical legume.

The second study will give us first-hand experience with a “2-4-2” maize-legume intercropping system in which 2 rows of maize are alternated with 4 rows of cowpea (Vigna unguiculata). An online publication by IITA (International Institute of Tropical Agriculture), Improved cowpea-cereal cropping systems: cereal-double cowpea system for the northern Guinea savanna zone, contains details on this approach including results of large scale farmer field trials in which total grain (cowpea + maize) production increased from less than 1.5 t/ha with traditional practices to over 3 t/ha with the 2-4-2 approach. In the ECHO Florida trial, we plan to measure grain production of the 2-4-2 maize system, with the legume being either cowpea, jackbean (Canivalia ensiformis), or ricebean (Vigna umbellata).

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