How can we measure the health of soil simply and cheaply?
This blog by CIAT describes two alternatives to adapt soil health indicator technologies in a simple way and at lower cost, so that they can be applied by smallholder farmers to evaluate the effect of different varieties of tropical forages and their management on the health of their own farm. The first alternative is the “wet aggregate stability test”, whereby soil samples are placed in a handmade sieve with a very dense cloth, to analyze the stability of soil aggregates. It revealed that soil samples that did not have plants showed much less stable aggregates, indicating a lower soil quality. The second alternative is the evaluation of microbial activity with tea bags, whereby microbial activity in soil is measured by seeing how fast microorganisms can decompose tea bags (organic matter). Results showed that in foraged soils the decomposition of tea bags was faster, suggesting that microbial communities are more active than in soil without plants, as there is a higher content of organic matter, which also gives soils a greater capacity to respond to a new source of nutrients. In addition, it was revealed that the highest concentrations of soil organic matter are generally related to better soil health, suggesting a more active microbial population and higher nutrient reserves that have the potential to be available for absorption by plants. In conclusion, the use of these simple evaluations would allow the farmer to better understand the quality of their soils, without large financial investments, and for timely decision-making. Through daily observations they know the state of their pastures and animal productivity, so they can better manage their pastures with a better recovery of grazing plots, ensuring more productive soils in the future.