Local Effective Microorganisms: Farmers Making Their Own Biological Inoculant for Improved Soil Health.

Culturing and using effective microorganism from locally derived microorganisms has become a common practice employed by farmers throughout Central America as well as parts of South America and Southeast Asia and increasingly all over the world. Despite its growing popularity there is little published research that explores the potential beneficial or detrimental effects of changing the biome of composts, manures and soils to which LEM is applied. The aim of our research was to explore the benefits and possible risks associated with incorporating LEM into agricultural management practices in temperate, ultisols. Through a series of experiments, the effects of LEM were analyzed when used in the cultivation of annual ryegrass (Lolium multiflorum), edamame soybeans (Glycine max), winter wheat (Triticum aestivum) and Toscano kale (Brassica oleracea). The experiments were carried out in different seasons, both in field plots and in a pots and in conjunction with different soil treatments and amendments. Through our research we have found LEM additions increased nitrogen mineralization within the first week after application when combined liquid swine effluent and when combined with composted broiler litter. We also found that the structure of free-living soil nematode communities was better maintained under conditions of high disturbance and enrichment when LEM was applied to soils. Finally, in a study using biosolarized soils, among soils that received no amendments or fertilization, the soils that received applications of LEM mineralized more nitrogen and produced higher kale yields.

Whether from extreme climate events such as droughts or from agricultural management such as sterilization, tillage and fertilization, soils and their microbial communities constantly face stress.

Based on our data, we conclude that LEM is an affordable, locally-available product that can fortify the sustainability of agroecosystems by building soil food-web resistance to these stresses and by improving N availability of manures.